Compressor not building pressure, overheats.

[Musicinabottle]

I have a 6.5 HP 60 gallon compressor I bought new about 20 years ago. It recently started getting hot as in smell extremely hot paint smell and no compressing at all. I drain this compressor far enough in between where I get about a half quart of water out the drain, but this time when I went to drain it, I got close to a gallon of water from the drain.

I pulled the intake filter and housing, as well as the output tube and it both draws air and is putting out air, but simply won't build pressure. The check valve off the output at the tank operates (moves) open and closed when I pushed on it with a drill bit.

What could be wrong with it? Need new valves?

 

[Boilerhouse]

Is it a single or dual stage? It seems to be working OK when there is no load connected to it, but...It acts like one of the valves is not seating and allowing air to cycle back and forth between cylinders. I'd be inclined to pull the head and check each valve, looking for dirt under a seating surface or obvious wear.

 

[KenC]

6.5hp sounds like maybe a Devillbis/airpro/or other name using an aluminum pump spinning at a fairly high speed. That pump uses a set of reed valves that are not individually serviceable and break or fatigue so that they no longer seal well. Only way to tell is to remove the head and valve plate.

I've had that pleasure a few times. First time the plate was $125 so I replaced it and the gaskets. The last time, the part had increased to over 250. I now have a different compressor!!

 

[Musicinabottle]

6.5hp sounds like maybe a Devillbis/airpro/or other name using an aluminum pump spinning at a fairly high speed. That pump uses a set of reed valves that are not individually serviceable and break or fatigue so that they no longer seal well. Only way to tell is to remove the head and valve plate.

I've had that pleasure a few times. First time the plate was $125 so I replaced it and the gaskets. The last time, the part had increased to over 250. I now have a different compressor!!

That'll be the case with me if it's going to anything remotely close to that cost. Okay, heads coming off then. Thank you for the info guys!

 

[cheesehead2]

I had the same problem some time back. Even though the check valve moved it still was bad. Bad seat/spring weak. Replaced it for I believe around 10.00 . Works great now.

 

[Musicinabottle]

No kidding huh? Well, I might just start with that then first. Quick, cheap and easy.

 

[Musicinabottle]

Well, perhaps stupidly, I pulled the top of the jugs off and apart from a fair amount of dirt and crud on the underside of the head, and a bit of corrosion on the reeds, but not near the seal, and a cracked in a couple spots, head gasket, that were there from day one judging from the dirt that filled in, everything looks fine.

Pulled the check valve next, and it could be blown or sucked through from either side. So I think we have the culprit!