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Mech Power Compressor problem

29415 Views 23 Replies 9 Participants Last post by  oldboy
I have a 2 hp twin tank Mech Power compressor, Model # M90002. It does not have many hours on it. I bought it new for odd jobs and pumping up tires. Probably not more than fifty.

It runs fine and then it will not build up pressure. It just stays around 25 pounds and runs and runs. I have found when I took off the head that there are two very thin pieces of metal over the holes in the "block" I'll call it. They get out from where they belong and then the comp. will not operate properly. I can put them back and it runs OK, but then they move again and it's the same.

Can anyone tell me the problem here? And of course how to fix it.

Also, I'm not sure that I'm putting them back correctly. The manual is not clear.:confused:

Any help will be appreciated.
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those reeds sound like they maybe are missing a little piece of them that holds them in place? Just a guess tho.
And Welcome to the PEF!
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Thanks for your reply. I wouldn't be surprised if there is something missing. I've had problems since I bought it. But I'll be darned if I know what it is.:(
Could be that all the parts were not put in it when it was built. I does happen unfortunately.
Welcome to PEF :D

can you post some pics with the head off, maybe one of us will see something you dont

I can do that. Later today. This morning my wife has other plans for me.
Here are the photos

Here are the photos. I hope someone can make some sense of them. I had them all captioned but the photo gods didn't like them.

First pic shows what you see when you remove the head. Two discs about 3/6 thick with a thin shim in between, about .010 thick.

Second pic w/ screwdriver as pointer shows small flat piece about 3/8 wide, 2" long and maybe .025 thick. I THINK these are the trouble makers. HOWEVER, when I took the head off today, they were in the correct location, which is in a depression milled into the 3/16 disc.

The last couple of pics show the way the parts are assembled. Disc, Shim, disc. There are gaskets glued to the head and the lower disc..


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i wonder if it is not sealing well to the "block"
It's running again

I put the head back on. Before I did I put some Permatex gasket goop, a very little bead, all around the 3/16 plates to maybe keep things from moving around. As soon as I hit the switch, it pumped up and stayed there. So we shall see. It usually performs this way when I put it back together, but then at some point won't pump up, but sits around 25 psi and just runs forever. :confused:
Running like a Timex watch!

I have used my compressor a couple of times since I "glued" it back together and it's running OK.. Only time will tell. But it's something to consider if your compressor starts acting up.

Merry Christmas to all.
Glad it is still working, and Merry Christmas to you also!
i dont know if you're problems are solved with the permatex. but to me it looks like those two hot spots on the 3rd to last photo of the thin shim are your culprit. the air was probably leaking out around the defects in the gasket causing your problem
mech air compressor HELP!!

Hello everyone
I have just joined and not couldn't find where to post a message, so am just replying to this one. My husband is a gear-head and used to take care of all the mechanical stuff and power equipment, but was recently diagnosed with cancer and doesn't have the strength anymore. I have been keeping things going, but the air compressor that I need to put air in the back tire of the riding lawn mower doesn't work. I plugged it in and pulled up the orange button but nothing happens, I accidentally hit my foot against the red thing on the one of the air tanks and some air escaped, then I turned the orange button on and it fired up for a few minutes then stopped. I can tell you guys that the psi on both dials are between 6 and 8. Any idea what might be wrong? or would you need more to go on?? I have low air pressure in one of my new car tires AND really low air pressure in my john deere tire. Help would be really apprecaited, thanks!!
Mech Power m90002 compressor

I have what sounds like the same problem as Phidor except that I found the pressure switch not working properly. Can't find anything on "Mech Power" and am looking for where to go to order parts for my compressor.
Is there an intake breather that might be letting small debris filter in to affect the sealing? If the reed is moving that’s a different story. Have you contacted the manufacturer on the matter? They might know of the matter and have designed "A Recall Fix". LOL!

I like this format of allowing attached pics to show info, which is worth "A 1000 Words". What is the limit on # of Pics and sizes (per windows properties)?
Can someone tell me HOW to contact the manufacturer? All I can find between the compressor and the Instruction manual is that the compressor was manufactured in China to specs. provided by Mech Power, Cupertino, CA.
Francis & momrisgbee, I think you would get better responses if you send your own separate post and include more info and pictures as to what you are referring to.

1. Related to pressure switch, you might be able to put it in a Run mode vs Auto to get it to run constantly. I was able to add a generic pressure switch (purchased locally) to my 1972 1 HP 10 Gal Sears Compressor. I also found bad starter capacitor contacts in the motor from years of Auto paint getting into the contacts (fine emory cloth fixed that). Look for sign of derbies being sucked into the breather end on the motor and that might show bad contacts.

2. For quick fix, I would suggest using a portable air tank to bring in the air you need to be safe.

3. Pictures of the units could lead to more info. If the pressure relief is the problem w/o the motor’s starter contacts being a problem try to by-pass it it and let your pop-off release pressure at a safe PSI.

4. Attached will be a dirty pic of my compressor, showing the contacts cleaned and generic valve (the best as can be seen).
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Slow Me! I just remembered that I was given this Monster due to a simple leak. Repaired it and loaned/gave it to our Son-In-Law. These little machines have worked great during my 6 years in the field helping build Habitat Homes. Plus, in the warehouse I c/n believe one could keep up with two nail guns over 6 months w/o our major 30 Gallon 5 HP Compressor was down. My test with this one was installing lug nuts and it passed (removing and installing) after checking installing with a torque wrench.
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