# Craftsman 150 PSI Air Compressor Regulator



## FLReno (Jul 3, 2017)

I have a Craftsman 150 PSI Compressor (Model: 919.167310). I just purchased a new Air Regulator to replace the original one that I thought had gone bad since it would drain the main tank pressure to whatever I set the Regulator pressure to.
However, when I replaced the old reg with the new reg, the same thing happened. The tank would reach 150 PSI however when I would lower the line pressure to 80 or 90 PSI, the tank pressure would also drop to or very close to that same pressure.

Is there something wrong with the new regulator as well or could there be some other issue causing the tank pressure to drop to what the regulator is set to? If I leave the regulator set to 140 PSI, the tank will maintain that same pressure.

Confused...


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## mark sr (Jun 13, 2017)

Where do you hear the air escaping at? How long does it take the tank to loose pressure?


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## FLReno (Jul 3, 2017)

I only hear air escaping from the Regulator knob when I adjust the Line Air Pressure.

The main tank pressure appears to drop at around the same pace as the line pressure does.

Once the regulator Line pressure has reached that pressure that it was set to, the main tank pressure is also maintained and no additional air is lost.

Both the main tank pressure gauge and the Regulator gauge tend to read almost the same pressure level within 10PSI.


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## raylo32 (Nov 25, 2006)

Fittings often leak. Either the ones connecting the hose downstream of the regulator or perhaps the tank water drain.


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## subbuilder (Jun 20, 2016)

Sounds like a problem with either a bad tank pressure gauge (letting the pressure drop), or the fittings between the two gauges.
Sub


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## FLReno (Jul 3, 2017)

Thank you for all the replies.

Just to recap, the tank maintains its pressure to whatever the line pressure is set to. If I set the regulator to 140 PSI that tank also maintains 140 PSI. Subsequently, if I set the regulator to 80 PSI, that tank also maintains 80 PSI as well. 

The water drain is good and not leaking and nothing down stream from the Regulator appears to be leaking.
@subbuilder 
I thought about the tank pressure gauge being an issue however I just assumed that the Regulator was responsible for maintaining tank pressure while controlling (lowering & raising) line pressure. 

The tank pressure gauge seems to indicate the tank pressure quite well. Does the tank pressure gauge provide any other function? Does it play a role in maintaining tank pressure as it relates to the regulator line presure?


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## mark sr (Jun 13, 2017)

The tank's gauge only purpose is to let you know the pressure in the tank. The regulator gauge lets you know what working pressure you have coming out of the tank.


How is your pump cutting on/off? is it cycling more than it should?


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## FLReno (Jul 3, 2017)

The pump appears to be working well and cutting off at 150 PSI as it normally does.

The pump will run a little longer though if the regulator is set to a lower PSI. Unfortunately, the regulator will leak air until it reaches the PSI that it is set to. However it also lets pressure out of the tank a well until the tank is at the same PSI that the regulator is set to.


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## mark sr (Jun 13, 2017)

Where is the air leaking? at the threads of the regulator?


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## FLReno (Jul 3, 2017)

Yes, the regulator appear to be releasing or leaking air where it should which is right around the adjustment knob. The threads of all the fittings are taped with Thread Sealant Tape and are not leaking at all.


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## DexterII (Jul 14, 2010)

If you haven't already, in lieu of adjusting the pressure up to what you want, try adjusting the regulator about 10-15 psi higher than you want, blow off a little air with your blow gun, then adjust the pressure down to what you want. So for 80 psi, adjust it to 90-95, blow off some pressure, then crank it back to 80. Don't know how common it is, but have seen some that acted like the diaphragm didn't like to fully seat when adjusting up.


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