D10R Implement Systems

Service Training

SESV1692 October 1997

Meeting Guide 692

TECHNICAL PRESENTA PRESENTATION TION

D11R TRACK-TYPE TRACTOR IMPLEMENT SYSTEMS

D11R TRACK-TYPE TRACTOR IMPLEMENT IMPLEM ENT SYS SYSTEM TEMS S MEETING GUIDE 692

SLIDES AND SCRIPT AUDIENCE

Level II--Service personnel who understand the principles of machine systems operation, diagnostic equipment, and procedures for testing and adjusting.

CONTENT This presentation discusses the operation of the implement hydraulic system for the D11R Track-type Tractor.

OBJECTIVES After learning the information in this presentation, the serviceman will be able to: 1. 2. 3. 4.

locate and identify all major components in the implement hydraulic system; locate and identify all filters, drains, and test points; explain the function of each component in the implement hydraulic system; and trace the flow of oil through the implement hydraulic system.

REFERENCES D11R Track-type Tractor Service Manual (9TR 1-Up) D11R Track-type Tractor Service Manual (8ZR 1-Up)

SENR1775 SENR9400

PREREQUISITES Interactive Video Course "Fundamentals of Mobile Hydraulics" (CD ROM) STMG 546 "Graphic Fluid Power Symbols"

TECD9001 SESV1546

SUPPLEMENTARY TRAINING MATERIAL STMG 679 "D10R Track-type Tractor--Introduction" STMG 527 "D11N Track-type Tractor--Part Tractor--Part 2: Undercarriage, Implements, and Operator’s Station" Video Tape "D11R Track-type Tractor/D11R CD Carrydozer--Introduction"

SESV1679 SESV1527 SEVN4173

Estimated Time: Time: 2 Hours Visuals: 27 (2 X 2) Slides Serviceman Handouts: 18 Line Drawings Drawings Form: SESV1692 Date: 10/97

© 1997 Caterpill Caterpillar ar Inc.

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TABLE OF CONTENTS INTRODUCTION INTROD UCTION ..................................................... ............................................................................................................. .............................................................5 .....5 IMPLEMENT HYDRAULIC IMPLEMENT HYDRAULIC SYSTEM.................................................................. SYSTEM.......... ......................................................................6 ..............6 Bulldozer Tilt Circuit........................................................................................................9 Bulldozer Lift Circuit......................................................................................................12 Quick-drop Quick-dr op Valves ............................................... ........................................................ ...........................................................19 ...19 Fan Drive Hydraulic Hydraulic System..................................................................... ......................25 Ripper and Pilot Circuits.................................................................................................26 Dual Tilt Tilt Valve Valve ..................................................... ............................................................................................................. ...........................................................33 ...33 CONCLUSION.....................................................................................................................40 SLIDE LIST..........................................................................................................................41 SERVICEMA SER VICEMAN'S N'S HANDOU HANDOUTS TS................................................... ................................................... ........................................42

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INSTRUCTOR NOTES

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D 11 R T R A C K - T Y P E T R A C T O R IMPLEMENT SYSTEMS

© 1997 Cater Caterpilla pillarr Inc.

1

INTRODUCTION

This presentation discusses the major design features of the implement hydraulic systems for the updated D11R Track-type Tractor (Serial Number 9TR 1-Up). The D11R D11R is an elevated sprocket design tractor equipped with the Power Train Electronic Control System and Finger Tip Control steering. • 35 3508 08B B engine engine

This tractor is powered by the 3508B turbocharged and aftercooled engine rated at 634 kW (850 hp) with a 25 percent net torque rise for excellent lugging performance. The power from the engine is transferred through a torque divider that results in maximum torque multiplication during heavy loading.

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IMPLEMENT HYDRAULIC SYSTEM COMPONENTS

RIPPER CONTROL VALVE

FAN MOTOR AND MAKEUP VALVE

DUAL TILT CONTROL VALVE

QUICK-DROP VALVES

PILOT VALVE HYDRAULIC AND DOZER TANK CONTROL VALVE

FAN PUMPS

IMPLEMENT PUMP

OIL COOLER AND BYPASS VALVE

2 IMPLEMENT HYDRAULIC SYSTEM • Contin Continuou uous s flow at at minimum pressure with controls in HOLD • Two sectio section n gear-t gear-type ype pump • Pilot operat operated ed control control valves

The implement hydraulic system for the D11R is a continuous flow design that permits minimum pressure in the system when the implement control valves are not activated. The pump for operation of the bulldozer, ripper, and oil cooling circuits is a two section gear-type pump (large and small sections). The system components include: the pump, pilot operated control valves, demand control fan pumps, dozer control valve, quick-drop valves, dual tilt control valve, and a ripper control valve. The system components control the flow of hydraulic oil to the appropriate implement cylinders.

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2

3

1 4

5 6

3

• Hydrau Hydraulic lic tan tank k components: 1. Oi Oill fil filll tub tube e 2. Ma Manu nual al air ve vent nt 3. Hyd Hydrau raulic lic oil fil filter ters s 4. Si Sigh ghtt ga gaug uge e 5. S• S•O• O•S S tap tap 6. Ta Tank nk dr drai ain n

The hydraulic tank is located on the right fender just outside the operator's compartment. The oil fill tube and cap (1) are located on the top of the tank. Inside the fill tube is a fine mesh screen which removes large particles of dirt or foreign material from the oil as the tank is filled. A manual air vent (2) and the breaker relief valve (not visible) are located near the filters. The vacuum breaker relief valve has a pressure setting of 3.5 kPa (.5 psi). Two hydraulic oil filters (3) are located inside the tank. The oil level sight gauge (4) on the front of the tank permits an easy check of the hydraulic system oil level. Always clean the sight gauge to be sure the oil level is visible. Dirt and stains on the glass frequently give the appearance appearance of a full full tank. A scheduled scheduled oil sampling sampling (S•O•S) tap (5) and tank drain (6) are located on the front of the tank. NOTE: The capacity of the D11R D11R hydraulic system is approximately 205 Liters (54 gal.).

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DOZER CONTROL VALVE HOLD TILT SPOOL

ROD END TILT CYLINDER

HEAD END TILT CYLINDER FROM SMALL PUMP

FROM PILOT VALVE LIFT RELIEF VALVE

FROM LARGE PUMP ROD END LIFT CYLINDER HEAD END LIFT CYLINDER

LIFT SPOOL

4 • Dozer Dozer contro controll valve component locations

The dozer control valve is located below the operator's station on the right side of the machine. Inside the control valve are two spools. One spool is for blade lift and lower and one spool is for blade tilt. The blade lift spool is manually operated and the blade tilt spool is operated by pilot oil.

• Manuall Manually y operate operated d dozer lift spool

The manually manually operated operated dozer lift lift spool has four positions: positions: RAISE, HOLD, LOWER, and FLOAT FLOAT. Only the FLOAT FLOAT position has a detent. de tent. The pilot operated blade tilt spool has three positions: TIL TILT T RIGHT, RIGHT, HOLD, and TILT TILT LEFT. LEFT. None of these positions has a detent.

• Pilot Pilot operate operated d blade tilt spool

The tilt circuit receives oil from the small section of the pump. When the circuit is not in use, the oil joins the large pump section oil flow to the lift circuit. If neither circuit is in use, the dump valve opens and sends oil flow to the tank. Both the tilt and lift circuits have load check valves and relief valves. The lift circuit has makeup valves for both the rod and head ends of the lift cylinders.

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DOZER TILT SPOOL HOLD

SECTION A-A

A

A

TILT RIGHT

TILT LEFT FROM SMALL PUMP

FROM PILOT VALVE FROM LARGE PUMP

5 Bulldozer Tilt Circuit • Tilt circuit compo component nent locations

The tilt spool has ha s three positions: TIL TILT T RIGHT, RIGHT, HOLD, and TILT LEFT. LEFT. The tilt spool is hydraulically operated by pilot pressure from a pilot valve which is controlled by the blade control lever. Movement of the lever to the right sends pilot pressure oil to the left end of the of the tilt valve spool. The pilot pressure moves the spool to the right and sends oil from the pump to the rod end of the tilt cylinder, and the blade tilts right. Lever movement to the left sends pilot pressure oil to the right end of the spool. The spool moves to the left, sends pump oil to the tilt cylinders, and the blade tilts left. When the blade control lever is released from either the TILT RIGHT or TILT LEFT position, springs return the tilt spool to the HOLD position. In the HOLD position, the oil from the small section of the pump goes around the tilt spool and joins the oil from the large section of the pump. The oil then opens the dump valve and returns to the tank.

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DOZER TILT SPOOL TILT RIGHT

SECTION A-A

TILT RIGHT A

TILT LEFT

A FROM SMALL PUMP

FROM PILOT VALVE FROM LARGE PUMP

6 • Pilot Pilot oil moves moves tilt tilt spool to right

• Pressu Pressure re opens opens load load check valve • Oil goes goes to tilt cylinder cylinder to retract rod

When the dozer control lever is moved to the TILT RIGHT position, pilot oil goes to the left end of the tilt spool. The pressure of the pilot oil moves the tilt spool to the TILT RIGHT position. In the TILT TILT RIGHT position, the oil from the small section of the pump cannot go through the control valve and the pressure of the oil increases. The increased pressure of the oil opens the load check valve. The pump oil goes through the open load check valve and around the tilt spool to the rod end of the tilt cylinder. The tilt cylinder, which is connected to the upper rear of the blade, retracts and causes the right end of the blade to move downward or TILT RIGHT. When the dozer control lever is released, the pilot oil at the left end of the tilt spool is drained. The spring at the right end of the tilt spool moves the spool to the HOLD position. In the HOLD position, the oil in the head and rod ends of the tilt cylinder is blocked. The tilt angle of the blade will not change until the dozer control lever is moved.

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With the tilt spool in the TILT RIGHT position, flow from the small section of the pump does not combine with flow from the large section. Pilot oil at the left end of the tilt spool has moved the spool to the right. Flow from the small section of the pump goes around the tilt spool and is sent to the rod end of the tilt cylinder. Because the small section flow cannot combine with the oil in the center chamber, the dump valve for the dozer lift circuit does not control the tilt circuit pressure. Instead, the tilt relief valve (at the top of the valve body) is used to limit the pressure in the tilt circuit. When the tilt cylinder pressure increases to 24300 kPa (3525 psi), the pilot valve for tilt relief will open and drain the spring chamber behind the valve spool. This condition permits the valve spool to open and limit the pressure in the tilt circuit.

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DOZER LIFT SPOOL HOLD LIFT RELIEF VALVE FROM LARGE PUMP LIFT SPOOL

7 Bulldozer Lift Circuit • Lift Lift cir circuit cuit components

The lift spool has four positions: RAISE, HOLD, LOWER, and FLOAT FLOAT. The lift spool is manually operated by the blade control lever. Movement of the lever to the rear sends pressure oil to the rod end of the lift cylinders, causing the blade to RAISE. Forward movement of the dozer control lever sends pressure oil to the head end of the lift cylinders, causing the blade to LOWER. If the lever is pushed forward past the LOWER position, the lever will go into int o the FLOAT FLOAT position. The FLOAT FLOAT position is the only position with a detent. In the FLOAT FLOAT position, the blade is free to move up or down according to outside forces. In the HOLD position, oil from the large section of the pump goes to the lift spool where it joins the oil from the tilt circuit.

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DOZER CONTROL VALVE HOLD TILT SPOOL

HEAD END TILT CYLINDER

ROD END TILT CYLINDER

FROM SMALL PUMP

FROM PILOT VALVE LIFT RELIEF VALVE


LIFT SPOOL

BALL RESOLVER

SHUTTLE VALVE

8 • HOL HOLD D pos positio ition n

When the valve spools in both the dozer control valve and the ripper control valve are in the HOLD position, the pressure of the supply oil (from both the small and large sections of the pump) through the dozer control valve is maintained at approximately 700 kPa (100 psi). The dozer lift spool is a "closed-center" spool, and the blade tilt spool is an "open-center" spool. In this view, view, both spools are in the HOLD (or center) position. Oil from the large large pump section enters the valve and starts to fill the chamber in the center of the valve body. body. Flow from the small section of the pump enters the valve body, flows around the opencenter tilt spool, and joins with the oil from the large section in the center chamber. All the oil around the closed-center lift spool is blocked. Because both spools are in the HOLD position, no oil flows to or from the lift and tilt cylinders, and the load check valves cannot open. .

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• Du Dump mp va valve lve

The spring for the dump valve plus the pressure of the oil in the tank have a combined force that provides a restriction to flow. flow. When the pressure in the center chamber increases above the spring force plus the tank oil pressure, the dump valve will open and permit the combined flow from the two sections of the pump to return to the tank. With both spools in the HOLD position, the dump valve provides a constant low system pressure which is available for instant implement response or for "feathering" action of the controls when activated by the operator.

• Shu Shuttl ttle e valv valve e

The shuttle valve resolves which hydraulic function (dozer raise and lower or ripper) will provide pressure feedback to the spring chamber of the dump valve. The shuttle valve is spring biased to the dozer lift and lower function. The stem shifts to the right when oil pressure is directed to the ripper valve port when the ripper function is requested by the operator or during an engine overspeed condition. When the lift spool is in the hold or center position, the spring chamber of the dump valve is connected to the tank. Tank pressure is transmitted through passages in the lift and lower spool that travel through the ball resolver valve and the shuttle valve before filling the spring chamber of the dump valve. During blade lift and lower functions, the cylinder load pressure signal is transmitted to the ball resolver valve, through the shuttle valve, to the spring chamber of the dump valve. This path is the same as when the spool is in the HOLD position. The cylinder load pressure signal is from the lift cylinder rod end during lift and from the cylinder head end during lower or float. The ball resolver valve directs the higher of either the cylinder rod or head end pressure to the shuttle valve. Because the shuttle valve spool is moved completely to the left, pressure oil from the center chamber cannot fill the spring chamber of the dump valve. For this reason, only the dump valve springs plus the tank oil pressure are regulating the pressure in the center chamber. chamber. This pressure will remain low as long as the lift and tilt spools are in the HOLD position, and the ripper circuits are not activated.

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DOZER LIFT SPOOL RAISE LIFT RELIEF VALVE FROM LARGE PUMP

LIFT SPOOL

9 • Do Doze zerr RAISE RAISE

This view of the dozer control valve shows spool movement and oil flow when the control lever is moved to the RAISE position. Movement of the dozer lift spool to the RAISE position opens the chamber at the left center of the spool, which is connected to the rod end of the lift cylinders. Since the oil around the lift spool is no longer blocked, pressure oil from the center chamber of the valve body can open the load check valve and flow around the lift spool to the rod end of the lift cylinders. At the same time that pressure oil is sent to the lift cylinders, oil also flows to the ball resolver valve. The ball resolver valve operates similarly to a check valve. With the lift spool in the RAISE position, the ball resolver valve permits pressure oil to flow to the shuttle valve, but blocks flow to the drain passage at the right end of the ball resolver valve.

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• Dump Dump valve conver converted ted to pilot operated relief valve

During blade RAISE, the lift cylinder rod end pressure is transmitted to the spring chamber of the dump valve through the ball resolver and the shuttle valve. The dump valve uses the rod end cylinder pressure combined with the spring to move the dump valve to the right until the supply pressure is 700 kPa (100 psi) above the cylinder pressure. If the pressure in the dump valve spring chamber reaches 22750 kPa (3300 psi) due to cylinder load or an end stroke condition, the relief valve will open and allow spring chamber oil to drain to the tank. When oil is allowed to drain from the dump valve spring chamber, the dump valve moves to the left and allows pump flow to pass around the dump valve to the tank. This operation prevents the system pressure from exceeding 22750 kPa (3300 psi) during blade RAISE or LOWER.

• Blad Blade e "feather "feathering ing""

An additional condition can exist during dozer operation which is referred to as "feathering the blade." If the operator moves the control lever a small distance to gradually raise the blade, flow to the cylinders goes through the throttling slots in the lift spool. Flow through the throttling slots can create the same effect as an orifice by restricting the flow of oil to the lift cylinder and and to the spring chamber of the dump valve. This restriction to flow causes a pressure difference between the oil in the center chamber of the valve body (system pressure) and the oil in the spring chamber of the dump valve (cylinder pressure). If the pressure difference is greater than the spring force, the dump valve will open and permit some of the pump flow to return to the tank.

• Load Load check check valv valve e prevents drift

With the lift spool in the RAISE position, the load check valve is used to prevent reverse oil flow from the cylinders which can cause "cylinder drift."

• FLO FLOAT AT pos positio ition n

When the lift spool is held in the FLOAT position by the detents on the end of the spool, the load check valve is open. The supply oil in the center chamber goes through the open load check valve to the head end of the lift cylinders. The center chamber is also open to the tank. The weight of the blade is the force that moves the dozer down. The oil from the rod end of the lift cylinders is also open to the tank when the lift spool is in the FLOAT FLOAT position. When an outside force moves the blade up, the pressure of the oil in the rod end of the lift cylinders decreases as the rods retract. The pressure of the oil in the rod end circuit is less than the pressure in the head end circuit. The higher pressure in the head end circuit opens a makeup valve to fill the rod end circuit as needed. The dozer control lever must be moved from the FLOAT position to move the lift spool in the dozer control valve from the FLOAT position.

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DOZER CONTROL VALVE HOLD ROD END TILT CYLINDER HEAD END TILT CYLINDER TILT SPOOL FROM SMALL PUMP

FROM PILOT VALVE DUMP VALVE


LIFT RELIEF VALVE

LIFT SPOOL

10 • Dump Dump valve valve has four four functions: 1. Relea Release se pum pump p flow flow with levers in HOLD 2. Pres Pressu surre compensation valve for pump

The dump valve in the dozer control valve has four different functions in the dozer lift and ripper circuits. When the blade lift and ripper control spools are in the HOLD position, the pressure in the spring chamber of the dump valve is the same as tank pressure plus 700 kPa (100 psi), which is the value of the spring. During blade RAISE or LOWER, the pressure in the spring chamber of the dump valve is the same as the pressure in either the head end or rod end of the lift cylinders. This pressure is felt through the ball resolver valve and the shuttle valve. With the cylinder pressure plus the spring force behind the dump valve, the supply pressure will be raised to a level of 700 kPa (100 psi) above the cylinder pressure. Flow control and fine modulation are possible because of the constant 700 kPa (100 psi) pressure behind the dump valve.

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3. Fl Flow ow con contr trol ol

When the ripper control spools are activated, pilot oil is sent to the right end of the shuttle shuttle valve valve and moves moves the shuttle shuttle valve to the the left. When the shuttle valve is moved, supply oil fills the spring chamber behind the dump valve. The pilot valve and the dump valve now function as the relief valve for the ripper circuit. Because oil from the drive end pump section goes to both a passage in the dozer control valve and to the ripper control valve, the pressure of the oil is always the same in both places.

4. Relie Relieff valv valve e for for main system operation

When the lift spool is in the RAISE or LOWER position, cylinder pressure is transmitted to the spring chamber of the dump valve through the ball resolver valve and the shuttle valve. A pressure relief valve is located within the dump valve spring chamber. chamber. This valve will lift off off its seat and allow the spring chamber oil to drain when the pressure in the spring chamber reaches 22750 kPa (3300 psi). When the relief valve opens, an imbalance exists between the pressure in the center chamber and a combination of the dump valve spring and the pressure in the spring chamber. A balance is achieved when the dump valve shifts to the left allowing oil in the center chamber to drain until the pressure in the center chamber is equal to the dump valve spring plus the spring chamber pressure. This method of controlling maximum system pressure is called a pilot operated relief valve.

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QUICK-DROP VALVE RAISE ROD END OIL

HEAD END OIL

11 Quick-drop Valves • Quick-d Quick-drop rop valve valve in RAISE position

All flow to and from the lift cylinders must go through the quick-drop valves that are installed on top of each cylinder. cylinder. The primary function of the quick-drop valve is to allow rapid blade lower without voiding the head end of the lift cylinders. Minimizing the amount of cylinder voiding reduces the time delay that will occur when a rapid blade lower is followed by an operator request for blade down pressure. The quick-drop valve is activated when a sufficient pressure difference occurs between the cylinder rod end oil and the oil in the spring cavity. cavity. This pressure difference is caused by rod end oil flow through an orfice in the quickdrop valve. The quick-drop valve is de-activated by high pressure in the head end felt through a slot in the spool. The quick-drop valves help to control four functions of the bulldozer: RAISE, LOWER at slow speeds, rapid LOWER, and LOWER with down pressure.

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When the dozer control lever is moved to the RAISE position, supply oil enters the quick-drop valve through an inlet and an orifice, flows through a sleeve, and is directed to the rod end of the lift cylinder. A small amount of oil passes through another orifice and fills the spring chamber behind the plunger. The pressure of this oil adds to the force of the spring, which pushes the valve against the sleeve. This condition causes all the oil entering the quick-drop valve to be directed to the rod end of the lift cylinders and all the oil from the head end of the lift cylinders to return to the tank.

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QUICK-DROP VALVE LOWER ROD END OIL

HEAD END OIL

12 • Quick-d Quick-drop rop valve valve in LOWER

When the dozer control lever is at less than approximately 75% of full lever travel, the lowering of the blade is controlled or modulated. Since the control lever is directly connected to the dozer control valve lift spool, the spool movement is proportional to the lever movement. The flow of oil that can pass through the control valve lift spool at any given position is a function of the pressure difference across the spool and the temperature of the oil. As mentioned earlier, earlier, the quick-drop valve is activated by high lift cylinder rod end oil flow in combination with low lift cylinder head end pressure. For this reason, the actual control lever position when the quick-drop valve is actuated can vary based on oil temperature and the blade weight, which determines the rod end oil pressure.

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When the dozer control lever is moved to the LOWER position, supply oil enters the quick-drop valve through a port and flows to the head end of the lift cylinders. The oil being pushed from the rod end of the cylinders returns through the control valve to the tank. Because of the weight weight of the blade and the resistance to flow, the pressure of the rod end oil may be higher than the head end oil. The flow of oil through the orifice is not high enough to create a large pressure difference between the oil in the port and the oil behind the plunger. plunger. The spring holds the valve against the sleeve and all the oil leaving the rod end of the lift cylinder returns through the control valve to the hydraulic tank.

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QUICK-DROP VALVE QUICK-DROP ROD END OIL

HEAD END OIL

13 • Quic Quick-d k-drop rop LOWER LOWER

When the dozer control lever exceeds approximately 75% of lever travel and the cylinder head end pressure is low, the quick-drop valve is activated and the blade drops very rapidly. The oil flow for a quick drop is the same as slow lower except that some of the oil leaving the rod end of the lift cylinder is directed into the head end of the cylinder. When the flow of oil through the orifice creates enough pressure differential between the port and the plunger spring chamber, the valve and plunger shift to the left and permit oil leaving the rod end to be added to the supply oil filling the head end of the lift cylinders. As mentioned earlier, during a rapid blade drop, the rod end pressure will be higher than the head end due to the blade weight. The resulting pressure differential and valve movement allow the rod end oil to flow to the head end of the cylinder and minimize cylinder voiding.

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QUICK-DROP VALVE LOWER WITH DOWN PRESSURE ROD END OIL

HEAD END OIL

14 • LOWER LOWER with with dow down n pressure

When down pressure must be applied to the blade, the operator moves the dozer control lever to the LOWER position. Pressure oil from the dozer control valve is sent to the head end of the lift cylinders. At the same time, oil fills the chamber at the left end of valve spool. As the head end pressure and resistance to downward movement increase, pressure in the chamber at the left end of the valve spool moves the plunger to the left against the force of the spring and moves the valve spool completely to the right. All the pressure oil from the dozer control valve is then sent to the head end of the lift cylinders. All the rod end oil is returned through the dozer control valve to the tank.

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FAN DRIVE HYDRAULIC SYSTEM SOLENOID

TO PILOT VALVES

FAN DRIVE MOTOR

RADIATOR

OIL COOLER TANK OIL COOLER BYPASS VALVE

FAN PUMPS

15 Fan Drive Hydraulic System • Fan pump pumps s part part of hydraulic system

The demand control fan system on the D11R is considered part of the implement hydraulic system because the fan pumps pull oil from the implement hydraulic tank and send some of the oil to the pilot control valves. Pilot oil shifts the blade tilt spool in the dozer control valve and also shifts the spools in the ripper control valve to control ripper lift and ripper tip.

• Demand Demand contr control ol fan system equipped with tandem axial pumps

The tractor is equipped with two hydraulic pumps for the demand control fan system. The tandem axial (variable displacement) pumps are located on the right rear side of the engine and are driven off the flywheel. The system adjusts the fan speed to match the cooling system demands based on an input signal to the engine Electronic Control Module (ECM) from the engine coolant temperature sensor.

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16

Ripper and Pilot Circuits • Ripper contr control ol valve (arrow)

The ripper control valve (arrow) has two spools (lift and tip), two makeup valves (one for the head end of the ripper lift cylinders and one for the head end of the ripper tip cylinders), and a load check valve. The ripper lift spool is operated with pilot pilot oil pressure and has three positions: positions: RAISE, HOLD, and LOWER. The ripper tip spool is operated by pilot pressure oil and also has three positions: SHANK IN, HOLD, and SHANK OUT. OUT. The valve spools have no detent positions. Movement of the ripper control lever to the left causes the ripper to lift and movement to the right causes the ripper to lower. lower. When the ripper control lever is moved forward, the ripper tip moves toward the machine (SHANK IN). Pulling the ripper control lever toward the rear causes the ripper tip to move away from the machine (SHANK OUT).

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RIPPER AND PILOT SYSTEMS

FROM FAN PUMP

RAISE

TO SHUTTLE VALVE TO DOZER CONTROL VALVE MAKEUP VALVE FOR HEAD END OF LIFT CYLINDERS

LOAD CHECK VALVE

LIFT CYLINDERS RIPPER TIP SPOOL RIPPER LIFT SPOOL

17 • Rip Rippe perr RAISE RAISE

When the ripper control lever is moved to the RAISE position, pilot oil is directed to the upper end of the lift spool and moves the spool down. The supply oil opens the load check valve, goes around the lift spool, and flows to the rod end of the ripper lift cylinders, causing the cylinder rods to retract and the ripper to raise. The oil that is forced from the head end of the ripper lift cylinders flows through the ripper control valve, around the lift spool, and returns to the tank. When the ripper control lever is released, the pilot oil in the upper spring chamber is drained. The lower spring returns the ripper lift spool to the HOLD position. The oil is blocked and holds the ripper in position until the ripper control lever is moved again.

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FROM FAN PUMP

LOWER

TO SHUTTLE VALVE TO DOZER CONTROL VALVE MAKEUP VALVE FOR HEAD END OF LIFT CYLINDERS LOAD CHECK VALVE

LIFT CYLINDERS

RIPPER TIP SPOOL RIPPER LIFT SPOOL

18 • Mak Makeup eup val valve ve

The makeup valve operates when the ripper is lowered quickly. When the lift spool is in the LOWER position, supply pressure oil is in the head end of the ripper lift cylinders and oil is returning from the rod end of the cylinders to the tank. If the cylinder head end supply pressure becomes less than the tank pressure due to the weight of the ripper, the makeup valve opens to let the tank oil add to the supply oil. This condition prevents cavitation in the head end of the lift cylinders and prevents delays in the operation of the ripper.

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FROM FAN PUMP

RAISE


LOAD CHECK VALVE


19 • Loa Load d check check valv valve e

The load check valve prevents reverse oil flow from the ripper cylinders. For example, when the ripper lift spool is in RAISE position, supply oil opens the load check valve and flows to the rod end of the lift cylinders. If the pressure of the pump oil decreases, the force of the spring in the load check valve will close the load check valve and hold the oil in the rod end of the lift cylinders. This condition prevents any movement of the ripper lift cylinders and will not let the ripper drop.

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FROM FAN PUMP

SHANK IN

TO DOZER CONTROL VALVE MAKEUP VALVE FOR HEAD END OF LIFT CYLINDERS

TIP CYLINDERS

LOAD CHECK VALVE

RIPPER TIP SPOOL RIPPER LIFT SPOOL

20 • SH SHAN ANK K IN IN

When the ripper control lever is moved to the SHANK IN position, pilot oil is directed through the ripper control valve to the upper end of the ripper tip spool. The pressure of the pilot oil moves the ripper tip spool down. The pump oil opens the load check valve and goes around the lift and tip spools to the head end of the ripper tip cylinders, causing the rods to extend and move the ripper tip toward the machine. The oil that is pushed from the rod end of the ripper tip cylinders flows through the ripper control valve and returns to the tank

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FROM FAN PUMP

RAISE


LOAD CHECK VALVE


21 • Pilo Pilott control control valves valves

• Dump Dump valve valve acts acts as ripper circuit relief valve

Three pilot valves are located below the dozer and ripper control levers to the right of the operator. The closed-center pilot valves control the dozer tilt, ripper lift, and ripper tip functions. No oil flows through the pilot valves when the spools are in the HOLD HOLD position. Each valve is centered by springs. When the ripper circuit is activated by the operator, pilot oil from the fan pump flows through the pilot valve to one end of the lift spool or tip spool. At the same time, pilot oil flows to the shuttle valve in the dozer control valve. The shuttle valve shifts to the right and allows oil to flow to the spring chamber of the dump valve which now functions as the relief valve for the ripper circuit. When the shuttle valve is shifted, the oil from both the small and large pumps is directed to the load check valve in the ripper control valve.

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PILOT SYSTEM BLADE TILT RIGHT FROM FAN PUMP

RIGHT TILT CYLINDER

FROM LARGE PUMP

22 • TI TILT LT RIG RIGHT HT

The tilt circuit receives oil from the small section of the pump. When the circuit is not in use, this oil combines with the oil from the large section of the pump for the lift circuit. The tilt valve spool has three positions: TILT RIGHT, HOLD and TILT LEFT. The tilt valve spool is hydraulically operated by pilot oil pressure from the pilot valve that is controlled by the dozer control lever. lever. When the dozer control lever is moved to the TILT RIGHT position, the linkage moves the pilot spool down. This movement allows pilot oil to flow to the left end of the tilt spool in the dozer control valve. Pilot pressure at the left end of the tilt spool moves the spool to the right and permits oil from the small section of the pump to flow to the rod end of the tilt cylinder. cylinder. As the rod end pressure increases, the rod retracts and tilts the blade to the right. Oil from the head end of the tilt cylinder is returned through the dozer control valve to the tank.

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DUAL TILT VALVE HOLD

TO ROD END

S2

PILOT OIL FROM FAN PUMP

S1

TO HEAD END

TILT CYLINDERS

FROM BLADE TILT VALVE

23 Dual Tilt Valve • Dual Dual tilt val valve ve has has three modes: - Du Dual al til tiltt - Sin Singl gle e tilt tilt - Bla Blade de pit pitch ch • Solenoi Solenoid d valv valve e contains two positioning coils • Toggle Toggle swit switch ch activates S2 coil • Trigge Triggerr switc switch h activates S1 coil

The dual tilt attachment provides the blade tilt circuit with three different modes of operation: DUAL TILT TILT, SINGLE TILT TILT, and BLADE PITCH. The control valve is located between the radiator grill doors and the radiator on the left side of the machine. The valve is activated by pilot oil pressure from the solenoid valve. The dual tilt valve contains a spring centered, hydraulically actuated spool valve and an electrically actuated solenoid control valve. The solenoid valve contains two coils and has three different positions. When neither solenoid is activated, the system operates in the DUAL TILT TIL T mode. When the toggle switch on the dozer control lever is moved forward, the S2 coil in the solenoid valve is energized and the system operates in the SINGLE TILT TILT mode. When the trigger switch on the dozer control lever is depressed, the system energizes the S1 coil in the solenoid and activates the BLADE PITCH mode.

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• Tilt cylinde cylinders rs contai contain n bypass valves

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Both the left and right tilt cylinders pistons contain bypass valves. These valves allow the completion of the tilt operation. When one of the cylinders reaches the end of its travel, the oil goes through the bypass valve to continue filling the other cylinder.

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DUAL TILT CIRCUIT DUAL TILT RIGHT FROM TILT CONTROL VALVE

TO ROD END LEFT TILT CYLINDER RIGHT TILT CYLINDER

TO TILT CONTROL VALVE

TO HEAD END

FROM FAN PUMP

FROM TRIGGER SWITCH

FROM TOGGLE SWITCH

24 • Dua Duall tilt opera operatio tion n

When the toggle switch on the dozer control lever is in the rear (OFF) position and the trigger switch is not depressed, neither coil in the solenoid valve is energized. The control valve is operating in the DUAL TILT TIL T mode. In the DUAL TILT TILT mode, oil flow is blocked at the solenoid valve and the dual tilt directional spool remains centered by the spring force.

• DUA DUAL L TILT TILT RIGH RIGHT T

When the operator moves the dozer control lever to the TILT RIGHT position, pump oil from the dozer control valve tilt circuit is sent to the head end of the left tilt cylinder. cylinder. This condition causes oil from the rod end of the left tilt cylinder to be forced back to the dual tilt control valve. The oil travels around the spool and is directed to the rod end of the right tilt cylinder. As the right tilt cylinder retracts, the oil in the head end of the cylinder is directed back through the dual tilt control valve and the dozer tilt control valve to the tank. Movement of the tilt cylinders in opposite directions causes the blade to tilt.

• Cylinde Cylinders rs move move in opposite directions



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This action of the dual tilt cylinders causes the blade to tilt to the right. When the control lever is released, the oil is blocked at the control valve, and the blade remains tilted to the right until the control lever is moved again. • Bypa Bypass ss valve valve provides full retraction for maximum blade tilt

The bypass valve in the left tilt cylinder piston allows oil to continue flowing to the right cylinder after the rod is fully extended from the left cylinder. The bypass valve allows oil to continue to flow to the right tilt cylinder rod end and provides full retraction for maximum blade tilt.

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DUAL TILT CIRCUIT SINGLE TILT RIGHT

FROM TILT CONTROL VALVE


TO TILT CONTROL VALVE

TO HEAD END

FROM FANPUMP

FROM TRIGGER SWITCH FROM TOGGLE SWITCH

25 • Toggle Toggle swit switch ch energizes S2 coil

To change from the DUAL TILT to the SINGLE TILT mode, the toggle switch on the blade control lever is moved to the forward (ON) position. The switch causes the S2 coil in the solenoid valve to energize. energize. The valve allows pilot oil from the solenoid valve to flow to the upper end of the directional spool and opens the lower end of the spool to drain. The directional spool moves down against the spring force to the SINGLE TILT TIL T position. In this condition, only the left tilt cylinder will extend or retract to change the position of the blade.

• SING SINGLE LE TILT TILT RIGHT RIGHT

When the operator moves the blade control lever to the SINGLE TILT RIGHT position, supply oil is sent to the head end of the left tilt cylinder. The rod extends forcing oil from the rod end to the tank. In the SINGLE TILT mode, the directional spool blocks oil to and from the right tilt cylinder keeping it stationary. The right tilt cylinder then functions as a brace. When the control lever is released, the oil is blocked at the control valve, and the blade remains tilted to the right until the control lever is moved again.

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DUAL TILT CIRCUIT BLADE PITCH FORWARD

FROM TILT CONTROL VALVE


TO HEAD END

TO TILT CONTROL VALVE FROM FAN PUMP

FROM TRIGGER SWITCH

FROM TOGGLE SWITCH

26 • Trigge Triggerr switc switch h energizes S1 coil

To change the blade pitch, the trigger switch on the dozer control lever is depressed and the S1 coil in the solenoid valve is energized. The valve allows pilot oil from the solenoid valve to be directed to the lower end of the directional spool and opens the upper end of the spool to drain. The valve spool then shifts up against the spring force to the BLADE PITCH mode.

• BLADE BLADE PIT PITCH CH FORWARD

For BLADE PITCH FORWARD, flow from the dozer tilt circuit is sent to the head end of the left tilt cylinder. cylinder. As the cylinder extends, oil from the rod end is pushed back to the dual tilt valve and is directed to the head end of the right tilt cylinder. The oil in the rod end of the right tilt cylinder is pushed back through the dual tilt valve to the hydraulic tank. As both tilt cylinders extend, the blade pitches forward. The cylinder extension rate is not the same between the left and right tilt cylinders. This difference is caused by the unequal volume of oil entering the left cylinder head end and the volume being pushed from the left cylinder rod end. The left rod end displaces a volume equivalent to the volume entering the left head end of the cylinder minus the cylinder rod volume.

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Since the right tilt cylinder head end receives oil from the rod end of the left cylinder, the right cylinder will extend at a slower rate than the left cylinder. When the dozer control lever is released, the oil is blocked at the control valve and the blade remains pitched forward until the control lever is moved again. • BLADE BLADE PITCH PITCH has priority

One additional characteristic of the BLADE PITCH mode is that the trigger switch has priority over the toggle switch. Therefore, if the trigger switch is depressed while the machine is operating in the SINGLE TILT mode, the S2 coil for single tilt is de-energized and the S1 coil for the blade pitch is energized. This feature ensures that the BLADE PITCH can always be changed, regardless of the toggle switch position.

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27

CONCLUSION

This presentation has discussed the major features of the implement hydraulic system for the D11R Track-type Tractor equipped with the 3508B engine. When used in conjunction with the service manual for this tractor, the information in this package should help the serviceman correctly diagnose a problem in the implement hydraulic system. For service repairs, adjustments, and maintenance, refer to the Operation and Maintenance Manual, Service Manual, and other related service publications.

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SLIDE LIST 1. Mod Model el vie view w 2. Com Compone ponent nt locatio locations ns 3. Hy Hydra drauli ulicc tank 4. Dozer control control valve valve (component (component locations) locations) 5. Doz Dozer er tilt spool spool (HOL (HOLD) D) 6. Dozer tilt spool spool (TILT (TILT RIGHT) RIGHT) 7. Doz Dozer er lift spool spool (HOL (HOLD) D) 8. Doz Dozer er control control valve valve (HOLD) (HOLD) 9. Doz Dozer er lift spool spool (RAISE) (RAISE) 10. Dozer control valve (HOLD) 11. Quick-dr Quick-drop op valve valve (RAISE (RAISE)) 12. Quic Quick-dr k-drop op vale (LOWER) (LOWER) 13. Quick-dr Quick-drop op valve valve (QUICK-D (QUICK-DROP) ROP) 14. Quick-dr Quick-drop op valve (LOWER WITH /DOWN /DOWN PRESSURE) 15. Fan drive drive hydrauli hydraulicc system system 16. Rip Rippe perr valve valve 17. Ripper and pilot pilot systems systems (RAISE) (RAISE) 18. Ripper and pilot pilot systems systems (LOWER) (LOWER) 19. Ripper and pilot pilot systems systems (RAISE) (RAISE) 20. Ripper and and pilot systems (SHANK IN) 21. Ripper and pilot pilot systems systems (RAISE) (RAISE) 22. Pilot system system (TILT (TILT RIGHT) RIGHT) 23. Dual tilt tilt valve valve (HOLD (HOLD)) 24. Dual tilt valve (DUAL (DUAL TILT TILT RIGHT) 25. Dual tilt valve (SINGLE (SINGLE TILT TILT RIGHT) 26. Dual tilt valve (PITCH (PITCH FORW FORWARD) 27. Mod Model el vie view w

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S T N E N O P M O C M E T S Y S C I L U A R D Y H T N E M E L P M I

Serviceman's Handout No. 1

P O S R E D - V L K A C I V U Q

E V T L A L V I T L L O A R U T D N O C D E N V A L A R V O T P O U E M K N A A F M E V L A R V E L P O P I R R T N O C

D E N V A L R A E V L S O S O A C P L Y I B O T N E P M M E U L P P M I S P N M A F U P C I L K U N A A R T D Y H E V E R V E L A L Z V A L V O D T O R D O T L N I N P A O C

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P M U P L L A M S M O R F

E V L A V L O D R L T O N H O C R E Z O D

E V L A V T O L I P M O R F

P M U P R E E G D N R I A L L Y M C O T F R I F L D N E D O R


R E D N I L Y C T F I L D N E D A E H

R E D D N N E I L D Y A C E T H L I T R E D D N N I E L Y D C O T R L I T L T O L O I T P S F E I E L E V L R A T V F I L

L O O P S T F I L

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L O O P S T D L L O I T H R E Z O D

T F E L T L I T

A A N O I T C E S

T H G I R T L I T A

A


P M U P E G R A L M O R F

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L O O P T S H T G I L I R T T L I R T E Z O D

T F E L T L I T

A A N O I T C E S

T H G I R T L I T A

A



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L O O P S T E F S I I L A R R E Z O D

F E I E L E V L R A T V F I L

L O O P S T F I L


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E V L A V L O D R L T O N R H E D O D N I C E N L D Y R A C E T E H L I Z R T O D E D D N I N




R P R E M E D U D I N P I N L E L Y G Y C R C T A T I F L I F L M L D O D N R N E F E D D A O E R H

E L Y D C O T R L I T

L O O P S T L I T

L O O P S T F I L P E V M L U A D V

F E I E L E V L R A T V F I L

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L I O D N E D O R

E V L A V P E S O I A R R D K C I U Q


L I O D N E D A E H

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L I O D N E D O R

E V L A V R P E O W R O D - L K C I U Q


L I O D N E D A E H

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L I O D N E D O R

E V L A P V O P R D O R K C I D - U K Q C I U Q


L I O D N E D A E H

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E R U E S V S L E A R V P N P W O O R D D - H T I K W C I R U E Q W O L

L I O D N E D O R


L I O D N E D A E H

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E V I R R O T D O N M A F

M E T S E Y V I S R C I D L N U A F A R D Y H

S E V L A V T O L I P O T


R E L O O C L I O R O T A I D A R

R S E S E V L L A I O P L O A Y V O B C

K N A T

D I O N E L O S S P N M A F U P

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S M E T S R Y E S E S I P T A P R I O R L I P D N A

E V L R A E Z V L O O D R O T T N O C


E K D V C A L E O A L H V C

T F I L L O R O E P P S P I R

E L T E T V U L H A S V O T

P I T L O R E O P P P S I R E D V N S L E A T R D V F E I A L D P N E U F I H L E O K R Y C A O F M

S R T E F D I N L I L Y C P M M U O P R F N A F

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S M E T S N R Y I E S K P T N A P I O H S R L I P D N A

E V L R A E Z V L O O D R O T T N O C


E K D V C A L E O A L H V C

T F I L L O R O E P P S P I R

P I T L O R E O P P P S I R E D V N S L E A T R D V F E I A L D P N E U F I H L E O K R Y C A O F M

S R E P I D N T I L Y C P M M U O P R F N A F

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M T E H T G I S R T Y I S L T T E D O A L I L B P


T R L E I T D T I N H L G I Y C R

P M M U O P R F N A F

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M O P R F M L U I P O T N A O F L I P

E V L A V T D L L I O T H L A U D D N E D O R O T

1 S


E E D V A L L A B V M T O L I R F T

2 S

D N E D A E H O T

S R E T D L N I T I L Y C

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D N E D O R O T

D N E D A E H O T

T R L E I T D N T I F L E Y L C

T I U T C H R G I I R C T T I L L T I T L L A U A D U D

E V L T A L I T V L M O O R R T F N O C


N A F P M M U O P R F

T R L E I T D T N H I L G I Y R C

E V L A T V L I L T O O R T T N O C

H C T I W S R E G G I R T M O R F

H C T I W S E L G G O T M O R F

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D N E D O R O T

D N E D A E H O T


T I T U H C G I R I R C T L T I L T I T E L L G N I A S U D

E V L T A L I T V L M O O R R T F N O C


P M U P N A F M O R F

T R L E I T D T N H I L G I Y R C




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D N E D O R O T

T D I R U A C W R R I O C F T H L C I T I T P L E D A A U L D B

D N E D A E H O T


E V L T A L I V T L M O O R R T F N O C


N A P F M M U O P R F

T R L E I T D T N H I L G I Y C R




SESV1692 10/97

Printed in U.S.A.

D10R Implement Systems

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