Have a 615 that is making oil again. Was told before I started here that they have pulled pumps from rear of motor to replace rear main seal twice. I had our lube guy drain and refill motor last night to gauge how quick it's making oil today. He said doesn't appear to be fuel and oil mixing My ?? Is why does this keep happening? Other mechanic says it is mixing hydraulic and oil. I have 25yrs in but this is 1st fleet I've worked for that has scrapers.
Guess you are already on the right track, find out how much oil is getting into the engine. Next figure out where that oil is coming from. Not familiar with the 615C but most Cats the flywheel is running in trans. oil so if it's coming from the hydraulics then it's NOT the crank seal. What pumps are run off the engine that would leak into the engine oil? I'm thinking both transmission and hydraulic pumps, either of which could be the source. Just another idea, how is the breather on the transmision or torque converter? If they are plugged that could cause excess pressure in the flywheel housing that would help push oil past the crank seal.
First important thing to identify is what oil's going where - transmission to engine, hydraulics to engine, what..? Once you've identified what's going down and what's going up the process of figuring out exactly how the oil is transferring all of a sudden becomes a lot easier.
Follow the above suggestions. Find the part number from Cat and get a blue and a red can of oil dye and put one color in hydraulic and the other color in transmission and see what color you get leaking.
A very good suggestion, and I can help you with the Part Numbers. The red dye is 9U-5031, the blue dye is 9U-5032. You may have to either really dose the transmission/hydraulic system with dye to get a visible colour change in "dirty" engine oil, or fill the engine with fresh clean oil before starting your tests, or both.
One note of caution when using either of those dyes, DO NOT use it while wearing good clothes! One drop can make a major mess. And don't dump the whole can in right off, maybe a tablespoon or two at first. And don't lick the spoon!
If I remember there is a hyd pump on the front right hand side of the motor it will fill your sump up it did it to me years ago I think we replaced that pump and fixed the problem. Good lucke
Thanks for the replies,been busy and haven't Sat down to update. First thing I did that day after having our lube guy drain and refill engine was looking for engine driven hydraulic pump because I have had problems with hydraulic oil in engine from bad pump seal. Ours doesn't have one in front housing. Added red and blue dyes to powertrain and to hydraulic. After checking each day we have not gained any oil at all. I found problem was with lube guys way of checking oil,by not getting engine leveled out. So luckily we don't have an issue. After studying hydraulic schematics I see where it is possible for accessory hydraulic pumps driven off trans could fill torque converter housing if pump was to start leaking. Last time according to our records it was torque converter seal leak,causing powertrain oil leak into motor. Thanks again for the replies.
B.M.F., Good news! Always nice when solution is just doing something right and not piles of parts. Would have sucked big time if you pulled a pump or converter to reseal it then found out later what the real probelm was. One of our mechanics many years ago was sent to a plant a couple hours away to "Replace head gasket" on a D343 engine in a 988 Cat. He started work then asked why they wanted the head gasket replaced. He was told it was because of the bad oil leak. He took some time to look over the engine and determined it was not the head gasket but just a valve/cam cover gasket leaking. Major difference in the amount of work he had to do that day!