OIL PUMP ASSEM. 9L9654 - Caterpillar

3406C And 3406E Truck EnginesUnnecessary turbocharger replacement can be avoided by accurate evaluation of residue or damage found in and around the turbocharger. In addition, evaluation of engine operation and performance with respect to oil usage and smoke, will provide supporting information. It is important to first check upstream in the turbocharger air inlet (between the air filter and the turbocharger inlet) for a possible leak. This is essential as any residue adhering to the compressor wheel may appear to be a leaking turbocharger compressor end oil seal. Grease (the type used to lubricate air filter seals and intake duct seals) and soot is the residue that most often combines on the compressor wheel and back plate to give the appearance of a leaking compressor oil seal.
The removal of a significant number of the turbochargers (that were removed for leaking oil) is caused by compressor wheel damage. The damaged compressor wheel causes wheel imbalance that results in a compressor end oil seal leak. The compressor wheel damage is usually caused by a foreign object in the air inlet. This cause and effect is usually missed during diagnosis.
Specific Review Criteria For Turbocharger Compressor End Oil Seal Leaks
1. Look for the presence of HEAVY ENGINE OILin the compressor housing outlet. Differentiate between engine oil and the grease used on the compressor outlet tubing seals. See Illustration 1.
Illustration 1. Turbocharger Compressor Housing Outlet. Heavy engine oil found here (A) may indicate a leaking compressor end oil seal. Grease found here (B) is used to lubricate compressor outlet tubing seals and is not a reason to replace the turbocharger.2. Remove the turbocharger compressor housing. Check for the presence of HEAVY ENGINE OILon the compressor back plate (C) and in the compressor housing. See Illustration 2. Do NOT confuse engine oil with the sticky black deposits from grease and soot. Look at the compressor blade deposits (D) to more conclusively determine that there is an upstream source of contamination.
Illustration 2. Turbocharger Compressor And Back Plate. The black deposits shown on the compressor back plate (C) and compressor blades (D) are from grease and soot.3. Examine the turbocharger turbine and compressor wheels for foreign object damage. Any compressor and/or turbine wheel damage usually indicates a problem outside the turbocharger.After the above criteria have been used to confirm or reject the need for a replacement turbocharger cartridge, some additional cleanup may be necessary. Accumulated oil or deposits should be cleaned from the compressor housing, charge air cooler, and air ducts downstream of the turbocharger before the system is reassembled. This cleanup will improve performance and also help prevent future misdiagnosis by another operator or mechanic.