air pressure too high- air compressor

[mjoekingz28]

I just got a used compressor. I probably need to do full maintenance on it but need to get the model # and find the online manual for it, besides that I have one problem that is worrying. There are two gauges, so I've found, one is the air that you can get out of it and the other is whats in the tank. The regulated (outlet) pressure gauge seems to be reading fine and is ok. The tank side gauge will skyrocket right past 200 (the max reading) and a little ways past that it will finally switch off.

I asked my dad about it (he who gave it to me) and he said he just never paid attention to the gauge and it always worked fine for him.

There is a twist handle there for what I guess is for adjusting the pressure, but I haven't touched anything until I get the manual. I'm just wondering is the gauge awry and/or the pressure relief "safety" valve not doing its job.


This was all Sunday when we used it with a nailer. After we finished the job I used the air gun to use up all the pressure and it went down to 0psi (on the outlet side). Today I checked and the tank side gauge was still reading around 150psi.


Not sure of the hp or size but it is 125psi max Craftsman.

 

[oilboy123]

The regulated gauge when cranked up should read close to the tank gauge when the pressure cutout switches out.

 

[Shannow]

If you think that it's overpressuring the reciever, don't run it.

Pneumatic failures are extremely not pleasant.

 

[robshelton]

Congrats on the compressor! The tank gauge is bad - its common. The regulator has the adjusting knob - it changes the pressure in the line past the regulator. Screw it in all the way for full pressure or out a bit to get the desired pressure. If you are worried about the tank pressure, look for the pressure release (pop-off) valve. Most are brass and have a small ring that looks like a mini key chain ring. With the tank at full pressure, pull the ring to open the valve just a little. It will make a lot of noise! But it should close quickly and you will know it's working. BTW, most of those valves have their pressure rating stamped on them in small letters so you may be able to read it.

Be sure and drain the tank often to get the water out of it. You will see the drain petcock on the bottom. Usually the watter is rusty so don't let it stain stuff you want to keep clean.

 

[car54]

My 150psi compressor reads 220psi on the gauge. the gauge has progressively gotten worse. I'm sure I should get a new gauge, but I haven't gotten around to it yet.

 

[mjoekingz28]

I checked it out today. Its a 12 gallon oil less 919.162121. Looked up the manual and there is no mention of an air filter.

The regulated pressure is at zero and the tank reads 150psi. I pulled the pressure release and no air escaped. That means the gauge is way off, correct?

I went to drain the tank and just a dab of black sludge got on my hand. Maybe it needs some pressure to expel the water. Didn't notice it the other day, but when I was moving it there was alot of water sloshing around. If pressurizing it doesn't work, I can remove the whole drain assembly, but believe there to be a risk of future leaks or stripping out the threads.

 

[01rangerxl]

Could just be a bad gauge as someone mentioned before. There may also be an adjustment screw inside the pressure switch that could be way out of adjustment.

Having some pressure in the tank does help with getting water out, but it should still drain if the valve is open. It's not uncommon for a valve to get corroded, clogged, etc. Finding a replacement shouldn't be too hard. Odds are Campbell Hausfeld part number D-1403 will fit. That part number comes with a thread sealer on it. You can probably also use teflon tape or Loctite.

 

[JTK]

Yes, like said, if that sucker did actually pump-up to 200psig, the PRV would have lifted on the tank seeing as though you do have one on there. Good thing!

I've had cheapy compressors blow the sensing line out of the fitting that goes to the cut-off switch if they over-pressure. Kind of a secondary 'weak-spot' for cheap ones.

 

[mjoekingz28]

I bought a new pressure gauge and it wasn't the right fit. I figured they were all universal and this one from Sears was 1/4" NPT threads. It was obvious it was too big for a replacement on my compressor. I will look further, but the gauge from Lowe's looked to be as big and will not fit. It looks as if I will have to live with it or special order it somehow.


Also, the tank drained just fine. It was probably a couple of gallons drained. I fully opened the valve and plugged in the compressor and let it run for a few minutes.

 

[01rangerxl]

Originally Posted By: mjoekingz28
I bought a new pressure gauge and it wasn't the right fit. I figured they were all universal and this one from Sears was 1/4" NPT threads. It was obvious it was too big for a replacement on my compressor. I will look further, but the gauge from Lowe's looked to be as big and will not fit. It looks as if I will have to live with it or special order it somehow.



Sears still carries most parts for it...
http://www.searspartsdirect.com/partsdir...st=&shdMod=