Fluids

LUBRICATING FLUIDS Lubricating fluid fill all surface irregularities providing oil films which slide against each other and  prevent metal to metal contact. The primary purpose of lubricant is to reduce friction friction between moving parts. TYPES OF OILS:

There are three types of oil is used –  1) Petroleum Petroleum based, based, ) !ineral !ineral based, based, ") #ynthetic #ynthetic based based $n modern engine synthetic oil is used because it provide both very low% very high temp. Performance. #ynthetic oil are also used in some accessories on the engine such as starters % &#' to  preclude using wrong oil in these units. These oil can also be found in modern airplane hydraulic s(s % in some instruments. The characteristics of both natural petroleum oil % synthetic oil have outlined in !$LL*+1 for natural oil !$LL-+ % !$LL"* for synthetic oils. MIL-L-23699(TYPE – II) II) is being widely adapted by b y military % civilian operator. There There are many advantages over other oil: 1) /igher viscosity  ) /igher load carrying characteristics  ") 0etter high temp. 2idation stability  3) 0etter thermal stability. PHYSICAL PROPERTIES PROPERTIES of OIL:  1) Low volatility  ) 4nti foaming 5uality ") Less co6e deposit 3) /igh flash point 7) Low pour point *) 8ide temp. 9ange *+ ; to 3++;) USES:  1) Lubrication  ) &ooling ") &apable of collecting foreign metal 3) il must protect lubricated component which r manufacture from noncorrosion resistance metal. 7) il also used for cushion between metal parts *) $t aids in forming seals between piston % cylinder -) $t is used to reduce abrasive wear of moving parts.

SERVICING  0efore servicing of engine oil s(s should refer to engine or a(c type certificate data sheet or or operating manual for correct oil. 4nother important consideration when servicing the oil s(s is to ensure that servicing is accomplished with in a short time < hrs) after engine shut down. !anufacture normally re5uire this in order to prevent over servicing

IDENTIFICATIONsynthetic oil are straw color when new but dar6er over time in service .The color change come from an o2idation inhibiter added to the oil which dar6ness after coming in contact with o 2ygen . The gradual dar6ening effect is not an indication of oil degradation but rather the inhibiter performing its function of absorbing o2ygen content in air that is normally present in the bearing compartment ./owever abnormally rapid or heavy discoloration of oil can be an indication of engine problem. PRECAUTION –

1. !a6e certain that oil is protected from contamination . 8hen servicing engine oil wear protective gloves = ". ;unnel should be clean. 3. #ervicing perform within shot time after engine shutdown.