Compressor Only Attaining 40 PSI

[stevebournelincs]

can you guys tell me what oil you use in yours please?
I have an issue where the pressure will only build up to about 40 psi and will not increase
I did change the oil and I think this actually made it worse
I did use compressor oil I will have to check whi h type I used
any help please

 

[rtbcomp]

Welcome to the forum. I've put this post in a new thread to make the topic easier to follow.

 

[Matrixx]

can you adjust the pressure?

 

[angellonewolf]

Is it more so the pressure switch?

Don't know much about comprssers but that would be my first look and there not expensive

Only a guess there will be more knowable people along in a min

Edited

 

[daleyd]

I think some more info would be needed before you could make a judgement such as

Does the compressor cut off and won’t go any higher or does it continually run and go no higher?

Is it direct or belt drive?

Is there any sign of escaping air when pressure builds?

 

[hotponyshoes]

Is it stopping when it gets to 40psi or is it still running and just not building up more pressure?

 

[rtbcomp]

Are you reading the pressure in the tank or at the outlet of a regulator?

 

[steviec_lj]

Have you emptied the tank or both air and water?

B-I-L had a small compressor that wouldn’t go above 25psi, until I drained the 11ltrs of water out of the tank.

 

[WorkshopChris]

Do you have a picture you can post up so we can see what we are talking about?
From the description of the problem i would be looking at the head gasket or valve plate. Providing everything else is sound and its not losing air from any leak.

 

[MoreWellie]

Assuming it gets to 40psi and continues to run but never gets higher then...

I had a similar problem on one and found it was just the head bolts had come loose over time. I was lucky as once tightened (within reason) it worked fine

if tightening alone doesn't work then I would remove the head and take a look at the gasket

if this isn't the case then turn the motor off and listen for leaks because to hold at 40psi it would most likely be audible

 

[waddycall]

Screw or piston compressor?

 

[Alan Reynolds]

I had a Clarke/Machine Shop compressor with a similar fault. It turned out to be a reed valve that had cracked in half. How to effect a cheap repair? I found some Moore and Wright feeler shim that had been sitting in a drawer for years and used the old pieces as a template and ground a new one of the right thickness. Still works fine. I did the same with another one when at the race track and this time I used a carbon reed from a motorcycle and just cut it with scissors. That's still working too. You haven't left the drain cock loose? does it lose pressure once it reaches 40 psi?