upright air compressor report

RICKG · Post by **RICKG** » Sat Jun 13, 2015 9:51 am

http://www.mastertoolrepair.com/air-com ... 21418.html

US General #3848 from harbor frt.
Purchased July 2010, it performed well for it's intended use for just under 5 years. June 2015 the valve assy is cooked. I'll be checking on replacement parts from the mfr and will report back. This reporting is FYI for those considering this unit.

In retrospect I would have spent the extra $$ to upgrade to larger, this unit was underpowered for some jobs (as expected) but overall was satisfactory.

RICKG · Post by **RICKG** » Sat Jun 13, 2015 2:36 pm

AHA!! Blown head gasket allowing the exhaust (to the tank) side to blow back into the intake side and out the air filter. Now to find gasket only.

whydahdvr · Post by **whydahdvr** » Sat Jun 13, 2015 8:33 pm

What size would you recommend based upon your experience and potential use?

Post by **wesk** » Sat Jun 13, 2015 10:48 pm

I would stay with 90-120 CFM at 175 PSI if I intended to sand blast and paint. Tank size should be at least 60 gallons or more. I prefer the two stage twin cylinder pumps.

whydahdvr · Post by **whydahdvr** » Sun Jun 14, 2015 5:52 am

OK. What about a compressor that could do that work as well as run air tools - like a nail gun, an air ratchet, etc.? Is their one you might recommend for all those uses or is it better to specialize?
I've got limited space so that and budget are the main limitations.
Thanks.

Xamon · Post by **Xamon** » Sun Jun 14, 2015 7:01 am

For air tools you need at least 10cfm at 90psi. I have one that does 12cfm at 90 with an 80 gallon tank, got it on sale for $500. This can run almost anything. The large sand blaster does beat it though, I get about 5 minutes of run time before hitting 80psi and having to wait for the compressor to recharge to it's max 125psi. So blasting is doable just not as fast as a larger unit.

Post by **wesk** » Sun Jun 14, 2015 10:10 am

The two tasks I listed in my first post are the toughest demands you can put on a compressor. The things you mentioned are easy for most any quality compressor and would be a piece of cake for the one I described.

I do a lot of heavy work and it fits my bill. If you never sand blast or paint the smaller units will work for you.

However if you wish to pinch the money and enjoy stopping in the middle of a task and waiting for your compressor to catch up then a cheapy may work for someone trying to do bigger jobs with smaller compressors.

RICKG · Post by **RICKG** » Mon Jun 15, 2015 1:26 pm

Found the gasket set from an outfit called General air compressor svc.
30 bucks + ship Ouch!! Should be at my door by weeks end. When I spoke to the rep there I mentioned I thought the failure was a result of a poor design at the web between the int/exh chambers where the gasket sits. He agreed and said he was aware of many head gasket failures on this model. He thought that the mfr had increased the width of the web on the head on later year models (mine was a 2010) and the replacement gasket is aprox 3/8" wide at the failure area rather than the aprox 3/16 on the orig gasket.
It'll be 2 weeks before I can do the repair and will post results.

Edit: the $30 price is for a COMPLETE pump gasket set, not just the head gasket. Head gasket n/a separately.

RICKG · Post by **RICKG** » Fri Jun 19, 2015 2:36 pm

Parts came in this PM. Note the difference in the width of the webs between the blown gasket (top) and the replacement (bottom). Yes I'd say they've addressed a design flaw.

Something the rep said was to install gasket, torque to 20 ftlb, run it up to temp a couple of times and re-torque which makes sense since it really is a piston engine.

Now to go effect the repair-a guy doesn't realize how often he goes to his compressor till it's down

4x4M38 · Post by **4x4M38** » Fri Jun 19, 2015 8:47 pm

Rick,
It sure sounds like you lucked into a parts rep that not only
knows what he is talking about but is also willing to share
his knowledge.

We have several suppliers in this hobby that are the same way.

It sure beats that deer in the headlights look I get often in the
chain auto parts and hardware stores.

RICKG · Post by **RICKG** » Fri Jul 17, 2015 8:21 am

Finally got around to finishing compressor repair. The head gasket install was straight forward and effective. However there's a relief valve located at the tank on the pressure line between the pump and tank. This valve releases pressure at the pump upon shut down allowing less work for the elect motor upon start up. A piece of the blown gasket had lodged in the valve rendering it ineffective. Once that was cleaned up we're good as new (fingers crossed).

I can recommend General A.C. Svc in Chicago for A.C. parts and advice.
1-800-444-1983 ask for George.