compressor problem

[George Max]

This morning my compressor stopped working. The motor hums, but it's not making the appropriate comressor noises that normally accompany that. The compressor in question is a C-H 4 gallon oil less pancake.

I had to leave for work, so at this moment haven't had the opportunity to disassemble anything to see what's really wrong. I assume that the compressor portion has probably seized in some way.

Since some of you have probably experienced this before, a sudden stop of the compressor, what was wrong with yours? Was it an easy fix with a rebuild kit? What should I be looking forward to when I open mine up? Was it worth repairing, or should I just toss it in the circular file and get a new one?

[Mortimer Schnerd, RN]

This may be overly obvious, but have you looked for a reset button? I've got a DeWalt Emglo that 1) doesn't want to run if it's cold outside and 2) has started running at about half speed and then stops. Restarting it gets a repeat of the cycle. There is a reset button that apparently when it trips, doesn't completely shut it off (or it has an intermediate setting... I don't know).

The solution for mine is hit the compressor with a heat gun to warm the oil up before I try to start it, then it cranks like it should every time. But in your case I wonder about the reset.

You did say you didn't have any time to look into it. Sorry if this was too obvious to mention.

[John E.]

I had a Campbell Hausfeld compressor do something similiar, turned out the small v belt that connects the piston to the motor had broken. In this case the motor was running but no compression. Still working on getting a replacement belt.

John E.

[George Max]

My compressor is in the basement, so it's warm. I was trying to fill a tire quickly with about 5 minutes until I had to leave for work. So yes, I had no time.

I'll look at this more closely when I return.

[George Max]

Interesting the number of things I've found to check on.

In addition to the reset button mentioned in the other posting, there's the pressure relief valve that might be stuck leaving pressure in the cylinder that the motor can't overcome to start compressing again. And now the belt.

[George]

Note that both remedies have been for oil-type compressors. I'd look to thawing the pressure gages if it's outside where condensation could occur. If the gage says "I'm full," the compressor won't start. Since yours hums, and is possibly a universal motor, I'd look to the brushes and commutator.

[Mortimer Schnerd, RN]

Do us all a favor and let us know what the problem ultimately is, so we can all learn from it.

[Gerald Ross]

Mine did this, and I took the cover off and found that while it was humming I could spin the fan and it would take off. It was the capacitor. 8 weeks later the replacement arrived from Harbor Freight and it worked fine. No longer have that piece of Junk.

[George Max]

Here's the fallout from this particular episode - I got home, and began to work on it. Of course, let's first take a look at how the unit looks while sitting on the floor.

The assembly containing the port to which the hose is plugged into was rotated about 45 degrees from it's normal position. Probably from tugging on the hose from the other end. When I rotated that assembly (port, pressure switch, and so on) the compressor began running normally when I plugged it in. !!!

So I'm not entirely sure what was wrong, but I'll bet it was related to pressure in the compressor and line to the tank that the motor could not overcome. I'm guessing that the relief valve that bleeds that off did not activate correctly when the compressor was tugged by the hose.

While I might not know exactly why this episode happened, I'll be addressing the fact that the above mentioned assembly can be rotated out of normal position and investigate the part that bleeds off pressure in the compressor.

[George Max]

See my reply to Mortimer telling the "rest of the story"

The only thing I want to append is a small bit of disappointment that this spoils my opportunity to justify to SWMBO the purchase of a larger unit more capable of running things like a die grinder. :(

[Mortimer Schnerd, RN]

Thanks for following through. Obviously, you have a safety issue that can only be addressed by the purchase of a large oil-lubricated unit. I wouldn't wait another day.

[George Max]

Actually wifey never prevents me from buying a new tool. This would be a matter of seeing how well it fits into the budget. I don't just buy things wily-nily and get blind sided by a credit card nightmare.

What I *do* think I'll be doing is putting it into a wooden box in case of explosion 'cause the pressure switch is malfunctioning.

[Patriarch]

George Max wrote in news: [e-mail]:

Well, then, you really DO have a bonafide safety issue with which to contend. I would not keep a compressor needing repair in my shop in a state where it could pressure up. Fix it, disable it or toss it.

The replacement becomes a second issue.

Patriarch

[CW]

A wooden box may make you feel better but that's all it will do. If that tank were to explode, the box won't help.

[Charley]

I was in a shop when a small air tank about the size of a pancake compressor blew up. We were lucky and nobody was seriously injured by it, but trust me, you don't want to even be in the same building when this happens. Even though I received no visible injuries, I think part of the hearing problems that I have resulted from it. I couldn't hear anything for the rest of that day. My hearing did improve after that, but it was never really right again. Do yourself and your family a favor and either fix that thing or trash it.

[George Max]

Ya know, that's not making me feel better about *any* compressor. I used to scuba dive. Having a tank with 3500lbs of pressure in it strapped to my back wasn't an entirely comforting thought aside from it being my air supply. What if it burst? Same with the compressor tank. We're relying on a lot of stuff working right.

[Mortimer Schnerd, RN]

I ran a dive shop for about 10 years (my first career). There used to be some equipment called AGA Divators that took 4000 psi if it was older; if it was newer and still had its + rating (given for the first 5 years of its life), you filled them to 4400 psi. You think I didn't pucker filling those?

The most likely time for the cylinder to fail is when you fill them. For the customer, the most likely event would be for the tank to heat up in your car on the way to the dive site and pop its burst disk... which made one hell of a noise and would create a spectacular cloud of vapor in the trunk of your car, No damage though, except to the $2 burst disk.

Now if a tank actually failed while being filled (2250-2450 for steel, 3000 for aluminum), it was teeth and eyeballs all over the room. A good way to get killed or maimed.... I've never known it to happen to anyone I knew but there were maybe three occurences I read about during the 10 years I did that job.

[George Max]

I thought the pressures were the other way around. Higher for steel, lower for aluminum.

I'm recalling that Pirate's Cove dive shop (Milwaukee) filled my steel

95 to around 3500psi when it was new.

The only aluminum tank I had was the little pony strapped to the side.

I too have only read of tanks bursting during fill. And I never heard of one failing during use. I hope I never witness a tank actually failing.

[George Max]

I'll say this - it ain't plugged in now.

[Mortimer Schnerd, RN]

Times have changed, obviously. When I was in the industry, almost all tanks were either steel 71.2 cf (at 2450 psi) or aluminum 80 cf (at 3000 psi). The aluminum 80s came with a lifetime warranty, which is good since I understand that some of them started developing problems around the neck sometime after I'd moved on.

WE had exclusively aluminum tanks in our rentals and for use in our classes... they were rust free and we thought they'd last forever. Steel tanks were notorious for rusint internally and requiring repeated tumbling to knock it out. If the rust was pitting, you had no idea how close the hole came to the surface of the tank... kind of scary if you thought about it.

But times move on. I was working in the industry from 1976 until 1990. 9 of those years I ran my own shop; the rest of the time I worked for others.