I have a 312c cat excavator that’s leaking motor oil somewhere under oil filter. I really need any advise or comments, thanks
Step 1. Determine exactly what is leaking. Step 2. Disassemble, replace gasket/o-ring/component Step 3. Reassemble. If this doesn't help, post the serial number so a Cat guy knows what he's looking at.
I've had a leak at the circled parts.
I changed o-rings and gaskets that are circled, do you know of any other places that it could leak oil? I put Teflon on 2 of the threaded plugs, I will get the serial number so you know which machine we looking at. Thank you
serial #CAT0312CTCBA02814. It’s leaking, I put like 4 gallons a day in it.
Did you change this one? And, Teflon is not needed, required, or to be used on 4, 6, & 31. #8 is to be snugged up, and then #9 snugged up, to prevent filter drainage.
Yessir, I changed that one too. That’s the one where you can see inner oil cooler tubes right?
Sorry not that one but yes I’ve changed it too
At 4 gallon a day, you should be able to see the leak. We certainly can't.
Step one: Go to Autozone and get engine degreaser, Four gallons a day is a lot. Get a lot of degreaser. https://www.autozone.com/fuel-and-engine-cleaners-additives/engine-degreaser/p/gunk-engine-brite-degreaser-15oz/522149_0_0 Step two: Hose everything down with degreaser. Let sit for 15 minutes. Step Three: Hose everything down with a water hose, or better a pressure washer. Try not to hose out the alternator. Step three: Take a blowgun and dry everything off. Use a flashlight to observe that everything is very clean. Step four: Start engine. Use the flashlight to observe the source of the leak. Until you know where it is actually leaking you are just throwing seals at it. Might as well just pull the engine and replace every seal on it in that case.
We cleaned and pressure washed it, I can see where it’s running down the side of the engine. Took a bore camera but can’t really see exactly where it’s coming out of? Thanks for your help I’m just gonna replace inner oil cooler and check the injection pump, it’s in that area. Between oil filter injection pump and inner oil cooler plate
Whatever works for you . . . I would stay there with degreaser, brake cleaner, air and a mirror and flashlight for a long time before I started loading the parts cannon, but that's just me.
Where the oil cooler tube come out to the oil filter base, does it have o-ring on the tube that comes out? The gasket the only thing that keeps the oil from leaking? I know it has two o-rings close to the oil filter. Thanks for earlier replies
The only O-Rings I can see are the two circled by HMC (Ref #10) in the illustration above. The cooler has gaskets (Ref #2) to the cover but surely if they were leaking it would be losing engine oil into the coolant.? Is there a possibility that something metal is cracked and it's not an O-Ring/gasket problem at all.?
Yessir that’s what I figured, I believe we found where the oil was leaking from. It was the gasket where the oil cooler mounts to that long skinny plate. Thanks to y’all for helping