Craftman 6.5hp 33 gallon, regulated supply only goes to 60 psi

by Aaron Chase
(Bonsall, CA)

The air compressor was bought in 1997. Has worked great for several years. The max pressure on this unit is 125 psi.


In the last year 2009, The tank shows 140 psi, which is normal. However when I adjust the regulated supply, the maximium psi that is obtainable is 60 psi on the nose. Which is strange. This unit use to go to 125 psi. If I keep on turning the regulater nob to increase the pressure, nothing happens after it reaches 60 psi and the nob starts to make a clicking sound.

Other than that problem everything works as it should.

I can buy parts for it but I have no idea what part is bad.

I thought the regulater is bad, however I read that they almost never go bad. So I would like some advice please.

_____________________________

Bill says...

What does the gauge on the tank, not the one on the regulator say?

If the tank has only 60 PSI in it, you can turn the regulator knob until you are blue in the face, and you won't get the pressure up past the tank pressure level?

Does your air compressor ever reach the cut out pressure level of 140 PSI any more, or does it simply keep running and the air pressure never gets past 60 PSI?

If that's the issue, read these pages.

Cheers,

Bill

Comments for Craftman 6.5hp 33 gallon, regulated supply only goes to 60 psi

Click here to add your own comments

May 05, 2010
reply
by: Anonymous

The tank is 140 psi. Which is where it should be. Regulated supply only 60 psi.

______________

Yes, I see that in the original post. Sorry I missed that.

Almost never go bad is not the same a never goes bad. So, I expect you either have debris in the regulator affecting the operation, or, the diaphragm or spring itself is suspect.

May be time for a new one.

B.

Click here to add your own comments

Add your own question or comment. It's easy to do. How? Simply click here to return to Craftsman Compressor Issues.

I have repaired all leaks. But still no pressure buildup.

by Cesar
(El Paso, TX USA)

I have a Craftsman 25 Gal. air compressor serial no. 919.165250 that i bought at a cheap prise because it had leaks. I have repaired all leaks including the one in the cylinder where the air was escaping. i bought and replaced the cylinder, cylinder housing, the rubber rings, the only thing i have not done is replace the gauges which i can see one of them is broken. But none the less i checked for leaks. i grabbed a windex bottle and added water with soap and i sprayed it almost everywhere and nothing leaks. But for some reason there is not air pressure. What do you think i missed?

Thank you

______________________
Bill says...

Cesar, assuming that the compressor actually runs :-), and there are no leaks as you say, then it seems to me that you may either have a valve issue, an internal gasket leak, or both.

Put your fingers near the intake port when the compressor is running. Is air getting sucked in, and / or is it getting blown out too? If it's coming out too, that suggests a valve failure, and all the compressor is doing is pulling air in and blowing it back out the same valve, without any going into the tank.

Bill

Click here to post comments

Add your own question or comment. It's easy to do. How? Simply click here to return to Craftsman Compressor Issues.

Craftsman 4.5 hp 30gal fills tank supr super slow?

by chassis mechanic
(Lomita,ca)

I have a Craftsman 4.5 or could be 3.5 HP 30 gal. tank and for a very short time it pumps normal, meaning the tank filling according to the tank pressure gauge fills quickly at first then it slows way down to about 2 psi per 10 seconds.

I believe the piston rings are shot or something in the head.
_____________________
Chassis Mechanic...

Yup, clearly something wrong with the pressure building on that Craftsman.

That it fills quickly at first, then slows down as the back pressure builds suggests that the problem is pressure related.

Though that could be the rings on the piston (any air blowing out the air intake when the compressor is cycling - that confirms that) I am more inclined to look at other components.

Run the compressor briefly with the air intake filter removed to see if air is huffing back out of the intake when the compressor starts to slow pressure build. If so, then the intake valve is compromised.

If not that, with the tank empty and the compressor off, I would remove, thoroughly clean, and replace the tank check valve. It is low likelihood that this is the problem, but it's a fairly easy check and if it works, it saves tearing down the pump.

What the Craftsman compressor problem might be is either a pressure valve problem or an internal gasket problem - the gasket starts to leak at a certain pressure and air cycles inside the pump rather than being pushed into the tank.

If you get to that level, you want to change the valve plate or valves and install new gaskets at the same time, eliminating both as the source of the problem.

Cheers,

Bill

Click here to post comments

Add your own question or comment. It's easy to do. How? Simply click here to return to Craftsman Compressor Issues.

919.167620 builds pressure to 95 psi. compressor keeps running

by Walt Barry
(Haiku Hawaii USA)

Craftsman 919.167620 builds pressure to 95 psi. compressor keeps running but doesn't add any more pressure.

i can hear air escaping from below the MAIN pressure gauge.

the air is escaping the whole time the pump is running.

if i tap what i think is the check valve,the air stops escaping and the pressure build to the set max 150 psi?
___________________
Walt, I am not entirely sure what you mean by ..."if i tap what i think is the check valve,the air stops escaping and the pressure build to the set max 150 psi?" If it means you stop the air flow from the tank check valve to the pressure switch, and if air is normally blowing out the bottom of your pressure switch, then you likely need to remove, clean, and replace the tank check valve.

This, too, puzzles me... "i can hear air escaping from below the MAIN pressure gauge."? A gauge is a device that indicates pressure. Where below the main pressure gauge is air escaping? If your main gauge is installed over the pressure switch, and air is bleeding out the pressure switch, then it could be the tank check valve, or it could be the diaphragm in the switch has a hole in it.

Cheers,

Bill

Comments for 919.167620 builds pressure to 95 psi. compressor keeps running

Click here to add your own comments

Mar 03, 2012
thank you
by: walt

i'm going to remove and clean what i think is the check value. thank you for your help
walt
______________
Good luck.

B.

Click here to add your own comments

Add your own question or comment. It's easy to do. How? Simply click here to return to Craftsman Compressor Issues.