Engine/Transmission (1994 - 1998) To rebuild or not ?

[mrineer]

I've got oil leaks at the oil pan gasket, front gear housing cover gasket, oil cooler gasket and at some other minor locations. I was going to replace the gaskets and check and repair other leaks as they become evident. This is a Freightliner FL70 with a 5. 9 12 valve Cummins aerial bucket truck with 190000 miles on it with a number of hours in idle time when the truck is in PTO lift mode. The truck is in good condition and everything works, and for a 93 it runs great. My question is at this time should I think about a rebuild or only replace parts as needed. With the leaks described is there another course of action ? My purpose is to keep it stock and run it for another 190000 miles. Dependability rather than speed.

 

[rattle trap]

i would think a rebuild would only be considered after doing tests such as oil consumption/pressure, compression, or if the bottom end is making noise.



you can buy a compression tester specifically for various cummins engines through harbor freight for $59. the other 3 are easy and free to observe.



but even if compression came back low, i might still hook up a leak down tester to the injector adapters from the harbor freight kit and listen for the location of the air leaks. could require head work (cracked or needs valve job) or could indicate a worn bore.



no need to waste money on what ifs though.



consider a oil sample as well. does your pto use a high idle?



in the mean time a diesel tune up and gaskets/seals may be all it needs.

 

[GAmes]

Rebuild with only 190k? That would be a serious waste of time and money. I've probably replaced every gasket there is on mine, and for now I have no leaks. I now use less than a quart of oil every 5000 miles.

 

[Missouri Mule]

The idling time could be a concern if the engine doesn't rev when using the pto. But I don't think you need a rebuild.

 

[Vaughn MacKenzie]

A Cummins could be tired at 190K if not maintained properly or run with a poor quality or leaking air filter.