CAT C12 with coolant in oil - Diesel Truck Forum -
Thread Details Posted by Monkey with a wrench, this thread has received 0 replies and been viewed 1330 times.

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post #1 of 1 (permalink) Old 05-02-2017, 02:13 PM Thread Starter
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CAT C12 with coolant in oil

I need to pick some brains. I have read some great posts on here regarding CAT's and Cummins and was wondering if you guys could help me out.

I have a CAT C12 in a 99 Peterbilt dump truck. 227,000 miles on it. I was working at another customers shop on his excavator when these guys came rolling in to talk to the owner. One thing leads to another and now I'm scratching my head.

CAT C12 serial #2ks14722 arrangement 172-8888

Coolant in oil. Customer states they were driving it hauling loads and towing there excavator and it started overheating. Checked oil and nice milky froth, coolant low (they have GREEN coolant in there!!). They changed oil and topped off coolant, kept driving for the day. They state no loss of power and told me, after asking all kinds of questions; that it takes forever to build air. I pressure tested the air compressor and its not leaking, but putting air to the air side of the compressor; it just whistles past the rings. Yesterday I drained the coolant out of the oil pan and pressure tested cooling side cold. No drop in pressure over an hour. Pressure test at 15psi. Started truck with pressure tester on system. No spike in pressure. Ran truck for an hour up to 150 F coolant and 125 oil. A few PSI increase but I attribute that to air expansion. Shut truck down and let it sit. Oh yeah, while idling I noticed white smoke coming from exhaust when it was getting warm. Smelled like oil, didn't smell antifreeze. Pulled exhaust flange from turbo, OIL POURING OUT. Turbo bearing and seal wiped out. So we have Turbo and compressor wiped out. From 12pm to 8pm left pressure tester on there. Started at 15psi and it had dropped to 8psi by 8pm. At some point either today or probably tomorrow I am going to pull the oil pan and look to see if its the water pump or if a liner is pitted and leaking.

So with all of that said, I am wondering if I am wasting time by looking and should just tell them it needs an inframe. Guess I need to look at a few mains and check condition as well as any liner scoring.

Anyone know if you can do a relative compression test with CAT ET?? Or a power balance??

So if this is short and convoluted, spent last night til midnight argueing with laptop at home and part of this morning. Guess that is broken too. Had to get the laptop out of the truck to writethis. Man, I hate computers sometimes..............just something else to break..........then you can't see whats broken!!
K, thanks for the help. Now off on my trusty steed to save the masses of broken crap with my magic wrench!!!

Thanks for listening
Monkey with a wrench is offline  

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