JoeH Posted April 12, 2019 Share Posted April 12, 2019 1979 R686ST, endt676 motor. Over time the air compressor pumps a real thick tar into the wet tank. Probably generates 1 gallon of it per 2 months. Rebuilt compressors don't fix it. Been doing it for years. What is going on??? Quote Link to comment https://www.bigmacktrucks.com/topic/56698-air-compressor-pumps-oil/ Share on other sites More sharing options...
Freightrain Posted April 12, 2019 Share Posted April 12, 2019 Air compressor inlet come from the air cleaner tubing? Pull that line and see if it is oily. You say the compressor is rebuilt and it didn't change anything? If it is not sucking oil on the inlet, then it has to be coming from the pump. When mine needed rebuilt, it only made oil milkshakes(water, oil, foam), not tar. Quote Larry 1959 B61 Liv'n Large...................... Charter member of the "MACK PACK" Link to comment https://www.bigmacktrucks.com/topic/56698-air-compressor-pumps-oil/#findComment-420477 Share on other sites More sharing options...
fjh Posted April 12, 2019 Share Posted April 12, 2019 2 hours ago, JoeH said: 1979 R686ST, endt676 motor. Over time the air compressor pumps a real thick tar into the wet tank. Probably generates 1 gallon of it per 2 months. Rebuilt compressors don't fix it. Been doing it for years. What is going on??? If you got one of those little donut air filters on there ditch it and plumb it in to the main engine air inlet or the inlet manifold that will turbo charge it! ! 1 Quote Link to comment https://www.bigmacktrucks.com/topic/56698-air-compressor-pumps-oil/#findComment-420485 Share on other sites More sharing options...
Freightrain Posted April 12, 2019 Share Posted April 12, 2019 Really? On the boost side? Never really thought about that. Would that really work okay? I still run the little box filter on the side of the pump. I've contemplated changing it over to the air cleaner pipe. I have the plate to convert it, as it came on the 237. I just never plumbed it so I used my old 673 filter. Quote Larry 1959 B61 Liv'n Large...................... Charter member of the "MACK PACK" Link to comment https://www.bigmacktrucks.com/topic/56698-air-compressor-pumps-oil/#findComment-420486 Share on other sites More sharing options...
terry Posted April 12, 2019 Share Posted April 12, 2019 Not sure if I would plumb it in on the pressure side of turbo, all the older mack engines with turbos I have seen had it between air filter and turbo. terry Quote Link to comment https://www.bigmacktrucks.com/topic/56698-air-compressor-pumps-oil/#findComment-420488 Share on other sites More sharing options...
JoeH Posted April 12, 2019 Author Share Posted April 12, 2019 It's set up as Terry stated. My e7 runs off the turbo side, but the endt676 runs it off the suction side between turbo and filter. Quote Link to comment https://www.bigmacktrucks.com/topic/56698-air-compressor-pumps-oil/#findComment-420490 Share on other sites More sharing options...
Hobert62 Posted April 14, 2019 Share Posted April 14, 2019 My 8.3 Cummins I just bought is plumbed right into the intake. It has a valve”forget the name” on the air compressor where the small filter would be,that limits the amount of pressure it will take so it doesn’t take all the turbo boost on a pull Quote Link to comment https://www.bigmacktrucks.com/topic/56698-air-compressor-pumps-oil/#findComment-420576 Share on other sites More sharing options...
blackdog2 Posted April 14, 2019 Share Posted April 14, 2019 If air filter is plug the motor needs air those individual air filters pick up a lot moisture . Quote Ed Link to comment https://www.bigmacktrucks.com/topic/56698-air-compressor-pumps-oil/#findComment-420585 Share on other sites More sharing options...
j_martell Posted April 15, 2019 Share Posted April 15, 2019 I'm chasing a similar issue on the RD (E6-350). Compressor intake is on the boost pipe between the turbo and CAC.... Could that be the source of the trouble? It became a problem when the boss man road tripped it to Alberta from southern Ontario a couple years ago, and the compressor was replaced (not sure if new or reman)....but theres still oil being pushed through sometimes.... The air dyer has been replaced twice...and it still sneezes oil sometimes.... Sorry OP; didn't mean to hi-jack your thread.... Quote Lack of planning on your part does not constitute an emergency on my part.... Link to comment https://www.bigmacktrucks.com/topic/56698-air-compressor-pumps-oil/#findComment-420667 Share on other sites More sharing options...
JoeH Posted April 18, 2019 Author Share Posted April 18, 2019 (edited) Your problem. Is my problem, not a hijack! I'm suspecting the "rebuilt" compressors are not actually rebuilt. I've popped at least 2 in trying to fix this, still does it. Are you sure your intake is from the boost side of the turbo? Or is it between the filter and turbo? I was hoping that turbo'ing the compressor would solve the problem, but if that's how yours is set up then it sounds like it won't.... Dryer isn't an option for me, I can't snot oil all over rich customers driveways. Frequently parked on driveways for 45 minutes, being a concrete truck... Edited April 18, 2019 by JoeH Quote Link to comment https://www.bigmacktrucks.com/topic/56698-air-compressor-pumps-oil/#findComment-420850 Share on other sites More sharing options...
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