DIYbanter - View Single Post - 20 yr old Air compresor

bq340

On 6/14/2011 7:37 AM, wrote:
My Sears 5 hp ( ok: 2 hp) belt drive compressor has been leaking at
the unloader valve whenever the unit is shut of or it turns itself off
(for longer than I care to admit). I have been limping along with
this problem by manually regulating the pressure via the breaker or
using enought air to keep the unit running for extended periods. I
finaly replaced the unloader valve last night. New one leaks just as
much - after a moment of thought - duh, that is what the unloader
valve is supposed to do. Problem is that the unloader valve is
unloading the tank along with any residual pressure in the pump.
Question is: where is the air leak coming from? The reed valves in
the head (I presume there are reed valves, have not opened up a
compressor in 30 years) or a check valve between the pump and the
tank? Any been there fixed that? Thought I would ask before digging
deeper into the compressor. THanks

Mine of the same vintage has a check valve in the tank where the pipe
from the compressor attaches, looks like a pipe fitting but is the check
valve. When it went I cut the pipe & installed a compression fitting
type inline.

MikeB