I just bought a older 1996-99 Devilbiss 60 gallon 6.5 claimed HP air america compressor off c-list for 50.00. The guy was honest in telling me he thought the pump was shot. He said he heard knocking. I got it home, put oil in it (it was very low) and fired it up. I didnt hear any knocking and the compressor went from empty to shut-off (125 psi) in just over 5 min. I thought all might be well. then i went to drain the tank and got lots of oil out of the tank. tried it again and more oil. I can open the valve on top of the tank and actually get a mist of oil while the compressor is running. It has an aluminum pump # ac0171. Should i try to fix this pump or just replace? It seems some parts are out there but some are not? Any recommendations on a fairly inexpensive but decent pump that would somewhat bolt up. I want one that can maximize the motor on the compresor which i think is about 3hp as it is marked 15 amps. Thanks alot!
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Devilbiss compressor oil blow by what should I do?
- Thread starter ls1jay
- Start date
Start from flat empty, and time the pump-up to the second. Also report the cut-out psi. I or someone else will calculate your pumps output from that. It should be putting out an average in the 10-12scfm range.
I am not certain, but I think, on those pumps, the crankcase vents into the intake side of the cylinder head (thus allowing the pump to re-ingest any blowby). That's fine and dandy, until for one reason or another, the pump has a problem which produces excessive blowby, which usually carries oil with it.
It is probably possible to find a rebuild kit for that pump. It may need nothing more than gaskets, rings, and a good honing.
I am not certain, but I think, on those pumps, the crankcase vents into the intake side of the cylinder head (thus allowing the pump to re-ingest any blowby). That's fine and dandy, until for one reason or another, the pump has a problem which produces excessive blowby, which usually carries oil with it.
It is probably possible to find a rebuild kit for that pump. It may need nothing more than gaskets, rings, and a good honing.
sberry
Banned
You can take the head off, run comp and can see if oil is coming up past the rings.
Went looking for my thread and realized I posted in the wrong section. Sorry! Anyways I filled up compressor from empty to 123 psi (shutoff)and it took exactly 5:15 seconds. listening closely i may be hearing a knocking, almost sounds like a vibrating effect that seemed to get louder with higher psi. the compressor speed seems equal at all pressures, it was at just over 60 psi at 2 and a half minutes. I cant seem to find any ring kits for this particular pump.
You can take the head off, run comp and can see if oil is coming up past the rings.
gonna try this next!
Went looking for my thread and realized I posted in the wrong section. Sorry! Anyways I filled up compressor from empty to 123 psi (shutoff)and it took exactly 5:15 seconds. listening closely i may be hearing a knocking, almost sounds like a vibrating effect that seemed to get louder with higher psi. the compressor speed seems equal at all pressures, it was at just over 60 psi at 2 and a half minutes. I cant seem to find any ring kits for this particular pump.
Works out to just about 13 CFM @ 65 PSI.
Time it from 80-100 psi I can give you a @ 90 psi figure
Seems pretty close to in spec
Thanks for doing that math for me! Not my strong subject!
I thought it seemed to fill up pretty quick, I was just bothered by the amount of oil. You would think if the rings were shot it wouldnt be pumping air very good??? Anyways the oil concerns me because i plan on painting with it eventually. I understand some oil out the pump is normal, but this just seems excessive. I will have a filter inline but you cant trust those to catch a hundred percent of contaminants can you? i just dont think something is right.
I thought it seemed to fill up pretty quick, I was just bothered by the amount of oil. You would think if the rings were shot it wouldnt be pumping air very good??? Anyways the oil concerns me because i plan on painting with it eventually. I understand some oil out the pump is normal, but this just seems excessive. I will have a filter inline but you cant trust those to catch a hundred percent of contaminants can you? i just dont think something is right.
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Works out to just about 13 CFM @ 65 PSI.
Time it from 80-100 psi I can give you a @ 90 psi figure
Seems pretty close to in spec
Beat me to it, but you can consider it doublechecked. I got the same figure.
That is pretty good output for that pump. Definitely rules out some major things, like damaged/leaking valves, or serious piston damage.
Ok, update. I got home and was going to start messing with the compressor and decided to check the oil and the level hasnt gone down at all. Iv cycled the compressor and drained the air out of it probably 7 or 8 times since i got it home and changed the oil. Im still getting a little oil out the bottom drain valve (not near as much) and a small mist on my hand when i crack the valve on top of the tank. Do you think when i put the compressor in the back of the pickup to take it home all the crankcase oil drained into the tank somehow and thats the oil im still getting?? Anyways, I have a feeling this thing is fine, no idea why the guy was selling it as in need of repair. Anybody have any ideas to rid the tank of all oil and see if its good to go?
If you laid the compressor down, then yes, you most definitely could have oil in wrong places. If, and where oil traveled will depend which side of the compressor was face down, but it's definitely possible.
I wouldn't worry about the oil in the tank. Once it's in the tank, and either stuck on the walls or settled out at the bottom, it's not going to make it back into the air stream. Through use of the compressor, water will condense on the inside of the walls, washing the oil down to the bottom, with time, and it will come out the condensate drain.
You could remove the output plumbing (from the pump to the tank), and clean it with brake cleaner.
You could also just open the valve wide open, and let the compressor just sit and run for an hour. See how much it can blow out with an hour's air flow. Some people think this is hard on a compressor (continuous running), but it's really not. If the pump isn't building pressure, it also doesn't produce heat.
The mist you see out the valve could be condensate. Even though it's water, it usually has a very oily feel to it.
I wouldn't worry about the oil in the tank. Once it's in the tank, and either stuck on the walls or settled out at the bottom, it's not going to make it back into the air stream. Through use of the compressor, water will condense on the inside of the walls, washing the oil down to the bottom, with time, and it will come out the condensate drain.
You could remove the output plumbing (from the pump to the tank), and clean it with brake cleaner.
You could also just open the valve wide open, and let the compressor just sit and run for an hour. See how much it can blow out with an hour's air flow. Some people think this is hard on a compressor (continuous running), but it's really not. If the pump isn't building pressure, it also doesn't produce heat.
The mist you see out the valve could be condensate. Even though it's water, it usually has a very oily feel to it.
K, so all the oil was bothering me. I decided to pull head off and one cylinder has lots of blow by. The crankshaft and connecting rod are all scarred up so im gonna have to replace the pump. I know these ebay pumps are probably not the best choice but i dont want to put a bunch of money in my $50.00 compressor. what do you think would be the best choice for my 15 amp motor. I would like to maximize the motor as much as possible.
http://www.ebay.com/itm/Pro-Alumini...021?pt=LH_DefaultDomain_0&hash=item4ab863dbf5
http://www.ebay.com/itm/280828412003?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1438.l2649
http://www.ebay.com/itm/120973744935?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1438.l2649
http://www.ebay.com/itm/3HP-Twin-Cy...065&pid=100011&prg=1005&rk=3&sd=280973612904&
if i could get by with one of the pumps under 150.00 that would be great. let me know what you think and thanks alot
http://www.ebay.com/itm/Pro-Alumini...021?pt=LH_DefaultDomain_0&hash=item4ab863dbf5
http://www.ebay.com/itm/280828412003?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1438.l2649
http://www.ebay.com/itm/120973744935?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1438.l2649
http://www.ebay.com/itm/3HP-Twin-Cy...065&pid=100011&prg=1005&rk=3&sd=280973612904&
if i could get by with one of the pumps under 150.00 that would be great. let me know what you think and thanks alot