Holman 185 CFM pressure valve open - blowing air

by Rainman
(Washington, MI, USA)

Holman 185 Compressor

Holman 185 Compressor

Holman 185 Compressor
Holman 185 Compressor Valve in question

During a recent job the machine began to run full blast. Found a burst hydraulic line and a pressure valve blowing air. The machine was quickly turned off and it did not run out of hydraulic fluid and didn't overheat. Replaced the line.

The compressor started fine except the valve is still blowing air and causing lower air pressure.

Have attached pictures of the compressor and the valve.

My questions are: Does this valve need to be replaced and what is it called? Or is this valve good and something else is wrong causing it to stay open and blow air? Need advice...

Holman 185 CFM Air Compressor
Compressor # RO175 P / 6190 NS ("RO175" could be ROA75 or RO275)
Ford 4 Cylinder Diesel Engine
Engine # 2701 E / S668848

Comments for Holman 185 CFM pressure valve open - blowing air

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Mar 08, 2015
relief valve
by: Black Diamond Industries

hey how are you guys all doing , I have the same compressor its a Holman ro175 ford dorset motor , if I were you ,I would try to take it apart because it might be seized

Sep 29, 2014
Type of compressor
by: Bill

You might also take a look at the pages on this site that describe the various types of air compressors, including reciprocating and rotary screw, among many.


Sep 28, 2014
valve failure?
by: Doug in s.d.ca

OK. Some compressors are actually a modified diesel where some of the cylinders do the air compression, and rest generate the power. That's be one kind of reciprocal.

Otherwise, a separate airend is typically a screw compressor.

So yours is a screw type?

Either way, why don't don't you pull that valve thing off and see if you can figure out what, if anything is wrong with it. Maybe you need to reset it somehow...

Sep 28, 2014
Valve Location and Accessiblility
by: Rainman

It is the top center (located at the front of the compressor) and the beginning of the manifold pipes. It is the valve pictured without the hose, nearest to the center of the picture, reminds me of a home water heater relief valve.

It is the air end of the compressor.

Not sure what reciprocal is, how does one determine what a reciprocal compressor is to answer your question.

The valve is accessible. Just turned it a couple of times without taking anything apart.

Sep 28, 2014
by: Doug in s.d.ca

Hard to see what's what here.

Is the second pic top center off what appears to be a manifold the valve?

And is that the airend? Is it a reciprocal?

Can you get it off without tearing down a bunch of other stuff?

Sorry for all the questions, but as you probably noticed, there isn't a whole lot of info on these on the web.

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