Any air compressor guru's out there?

[jimbob200521]

Well here I am again, asking for help from the OCC guru's! In my incessant online searching of all things that I "need" for my shop, I came across a Trades Pro 30 gal 5hp air compressor. Looked good, price was way too high, but specs seemed good for what I'd do; 5hp, 75% duty cycle, 5.6-6.4 SCFM flow, and 125psi max pressure. Anywho, got the guy to a good price for it and made the deal. Got it home and fired it up. After a quick diagnostics, I changed the oil (who knows how long it'd been), replaced a few leaky fittings, and gave it a go again. After 15-20 minutes, it still hand't pumped up to full pressure. I'm guessing it got to about 60-80 psi as the gauge was just about beyond readably fogged up.

I'm guessing the rings are bad on this as it shouldn't take that long to fill up. Basically, I'm pretty new to compressor workings such as this and want to know if it's worth putting a few bucks into this to get it back to repairing. Here's a link to the service manual, parts breakdown are on pages 17-18. I'm guessing I need parts 10 and 11 (rings for the piston) but I haven't torn into it yet so I'm not sure. Where should I start with this thing? Thanks guys!

http://www.alltradetools.com/pdfs/ne...835521_eng.pdf

[J-Mech]

Did you check the air filter? Are you sure the gauge works? If it's foggy, it may also be broken. Which gauge? There are two, one before and one after the regulator. I always remove the regulator. That way you can get full pressure when you want it. If you need a regulator for something (painting, or a nail gun) use a small regulator in line at the gun. That way you can adjust pressure right where you are working and don't have to walk back and forth to the compressor.

If you do decide to replace parts, it's more likely the reed valve (part #5) although the rings could be worn. I don't know how much the parts cost, but most of these compressors aren't worth the time.

[olds45512]

before you go ordering parts get a squirt bottle with some soapy water in it and check over the pump and and relief valve to make sure there isnt any leaks. check good around the head because when they leak it just pushes the air out instead of into the tank and it will take forever to fill.

[jimbob200521]

Originally Posted by J-Mech

Did you check the air filter? Are you sure the gauge works? If it's foggy, it may also be broken. Which gauge? There are two, one before and one after the regulator. I always remove the regulator. That way you can get full pressure when you want it. If you need a regulator for something (painting, or a nail gun) use a small regulator in line at the gun. That way you can adjust pressure right where you are working and don't have to walk back and forth to the compressor.

If you do decide to replace parts, it's more likely the reed valve (part #5) although the rings could be worn. I don't know how much the parts cost, but most of these compressors aren't worth the time.

Air filter is removed (for testing purposes). Regulator also removed, I don't care for them for the same reasons you listed, John. As for the reed, I'll check that out tomorrow, I'm done in the shop for tonite.

Originally Posted by olds45512

before you go ordering parts get a squirt bottle with some soapy water in it and check over the pump and and relief valve to make sure there isnt any leaks. check good around the head because when they leak it just pushes the air out instead of into the tank and it will take forever to fill.

I'll check out the soapy water suggestion, hadn't made it that far yet. I will check the head more in depth, though, as it gets quite hot. It is clean, however, as I've checked that and air is flowing over it freely. I do say it gets hot because after a few minutes of running, I can't touch it without it getting too hot to touch. Anywho, I'll check the head gasket to make sure it isn't leaking.

My next problem is finding an outlet for these parts. After a QUICK search online, the only outlet I've found is through the vendor. I'm curious if Napa or O'Reilly carries any parts, althoug if it's a gasket I suppose I could make my own.

[kostendorf]

If it proves too expensive to fix Harbor Freight sells just the pump for a pretty decent price and they guaranty them. The one I bought has a 10 year warranty and the cashier told me to bring it back in that time working or not for a new one.

[Alvy]

I just bought a rebuild kit for my Campbell hausfeld 60 gallon and the guy had different kinds, it was an ebay store. Had to measure my piston diameter as there were 2 for mine available, came with all the reed valves, screws, gaskets, etc. decent price too. If you find out it's internal. This sounds dumb but a slipping/loose belt will give you the same issue as well.

[J-Mech]

Originally Posted by kostendorf

If it proves too expensive to fix Harbor Freight sells just the pump for a pretty decent price and they guaranty them. The one I bought has a 10 year warranty and the cashier told me to bring it back in that time working or not for a new one.

Originally Posted by Alvy

This sounds dumb but a slipping/loose belt will give you the same issue as well.

This compressor is direct drive. No belts. If he buys a compressor at HF, he'll need a motor too.

[Oak]

Jimbob, I'm thinking the reed valves may be your problem. How much does the intake "suck" when the pressure in the tank gets higher? Like an engine if it were the rings I would think you would have a lot of blow by.

[Maxwelhse]

I have a silly question... Did you ask the seller if you can return it because it doesn't work as advertised or possibly help to pay for repair parts?

[DoubleO7]

Since it is supposedly developing 60-80 psi, would it not also blow the crank oil dipstick out if it was a push-in style?
If the rings or bore were bad.