sears pressure relief valve on top of the smaller of two pistons

by rick
(houston tx)

have sears 60gal. tank, 5hp. holds 175psi but prv opens on top of the smaller of two pistons at 80psi what to do?


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Bill says...

Rick, I am assuming that this is a new condition, and that nothing unusual has been noted on the compressor before this started happening?

The PRV will go off if the pressure in that piston exceeds the PRV set point, or the PRV is failing.

The pressure can exceed set point if the valve that controls the outflow from that cylinder is not working properly. If that valve does not allow air to escape under pressure, then the pressure builds too high and the PRV pops.

If the PRV was in the line to the second cylinder, and that second cylinder was plumbed into the tank, then I would say that it was the intake valve on the second cylinder that would be causing your problem.

Cheers,

Bill

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Sears compressor ~ Changing a Flapper Valve

by Michael
(Dallas, Texas)


I bought an old Sears two-cylinder air compressor and it works great except one of the flapper valves is broken and it leaks down over about an hour.

I pulled the cylinder head (that's how I found the broken flapper) and the 3/16 hex screws holding the remainder of the flapper are so shallow-headed I can't get a bite on them with any tool. They look like brass, too.

What do you suggest for getting those fasteners out/off?

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compession ring - help to reassemble

by Jeff
(Lerna,Il)

I have a new compression ring for a Craftsman 919.167300. 1st- it looks like (1) in the breakdown, but the people I bought the ring show(use 2).

Can't imagine because I can't hardly install (1). #2 - I can install the compression ring onto the connecting rod, but how do I get it in the cylinder sleeve? Jeff

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Bill says...

Jeff, I haven't taken your compressor apart, so I cannot offer advice on rebuilding it with the new compression ring.

Some photos of your compressor issue would be nice to help understand your problem, and I invite other Sears compressor re-builders to offer any advice you may have for Jeff.

Cheers,

Bill

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