Ive got a Cat IT28B (serial 1HF00904) that has oil leaking from the starter gasket. I’ve been doing some reading and from what I’ve read usually that gasket will leak if the tranny fluid is overfilled or a plugged breather. My question is it isn’t a small leak. At idle there is a steady stream of oil coming out. It is clear like hydraulic and the tranny level is just about empty. The leak went from not leaking at all to this steady steam instantly. (It didn’t start with a drip and get consistently worse). I’ve checked the starter bolts and they are both tight. From the reading I’ve done it doesn’t seem like there’s a large amount of oil going through there. It is currently low on oil (I haven’t checked the breather yet) but can a failed gasket cause a leak that large? I wouldn’t expect that kind of pressure in there. I’m just trying to get a feel for what could be wrong before I take the starter out and put a new gasket in.
First thing I would be checking is the breather on top of the transmission case. If it is plugged it could be cause the oil that normally leak from converter and into the area where the starter is and build up pressure. See item #20 circled in red in this picture:
I would be worried about the o-ring leaking between torque and engine if this machine is configured that way. Any issues with low transmission oil or might be a blown pump seal from the hydraulics into the torque. Look for low hydraulic oil and or low trans fluid and go from there.
In his first post he did mention that transmission oil was very low! I'm pretty sure this machine like many Cat loaders and such is what is called a "wet flywheel". In other words there is a normal amount of leakage from the converter that then drains back by gravity into the transmission case. The reason I suggested checking the breather is if it is plugged it can cause back pressure on the drain line(passage) from the converter causing oil to build up in the converter/flywheel housing. When this happens it can lead to leaking into the starter or out the starter mounting gasket area. I have seen machines that got so bad the armature of the starter was ruined from the oil.
Ok, read it a little to quick. Lol used to standing beside a machine to trouble shoot. New to this so first brain malfunction completed. Thanks for bringing clarity.
I've also seen where someone didn't put in the gasket between the starter and flywheel housing. I always looked for a ground strap on the back of the starter to the engine block when I saw those leaks. If it was there I figured there was supposed to be a gasket on the front of the starter. The IT28/928 might be different though. Everything sits a lot lower and tighter in the machine. I would probably ask if there were any other issues such as low power and overheating.
I recall back when a local shop was just getting into heavy equipment starter repairs. We had a starter that had just been rebuilt by them and short time latter it was leaking oil out around those plugs for access to the brushes. Removed starter and I took it apart. Found the seal for the armature shaft to be very distorted. When I said something to the repair shop they did not think those seals were really that important. Seems they had never heard of a "wet flywheel" machine!