jim wrote:
EW wrote:

My OLD 220 Volt Sears air compressor (model # 106.15378) with twin cylinders
recently quit being able to compress more than about 65 psi into the tank.
At that point, the motor still runs, the fan belt starts to squeal, and the
cylinders will no longer run. I can't even "turn" the flywheel by hand.
Lowering pressure a lot lets it run again.
I'm assuming something (reed valve??) is causing the high pressure air to
"work" against the cylinders so hard that they will simply not pump. (I
wonder if storing the compressor in my hot Texas shop -- 140 degrees in mid
PM -- contributed to this!)
Any ideas? "IF" it's a reed valve, is it accessible at the top of the
cylinder block? Is there a difference between the "input air" and output
air" reed valve? Can I fix a reed valve? ANY comments would help!!
Thanks.

EW
you have two valves in almost all compressors:
[.....]
you might have problems????? hope for the best... either sears or any
pump replair shop can sell you a check valve... the unloader valve at
sears is part of the whole diaphram valve that controls the pressure
from the tank.. i could not get one from sears.. you had to buy the whol
thing.. so i went to a pump repair place.. they fix air compressors and
got one there for about $15.00 also... these valve are pretty standard
sized and interchangable for most compressors... hope this helps.

Grainger sell unloader valve, his would cost under 10bucks for an inline.

--Loren