AirAmerica Rex: Output pressure keeps climbing

[cannibalpope]

I bought a used AirAmerica Raptor Rex from a kid, sent it into AirAmerica and had them rebuild it. Got it back and used it without problems for a few days then poof.

The symptoms are: When I air the tank up the output pressure keeps climbing. It will slowly increase from 100 (or whatever I preset it too) and climb past the max on the gauge (1200).

After 1000 it starts to hiss out the back of the regulator (through the little whole that reads, "pressure relief" and spits out grease.

I've completely stripped the regulator and rebuilt it with the same results. The internals look flawless.

Before I send this back to AirAmerica, anyone else have any advice on what I might be missing?

[Aegis]

Just curious, as I have a couple of raptors - how are you measuring output pressure?

[vf-xx]

I had something similar happen to my tank, but that was whenever I got it filled. Between 1200 and 2200 psi my tank would do that. Turns out the piston O-ring needed replacing.

I think the Reg seat did too, but I don't remember for sure.

[abarnhar]

I have a Raptor and had the climbing problem also.

It's most likely your reg seat (the big fat white washer). Look for nicks or dirt on it. If it isn't sealing well, then pressure from the tank can seap into the reg, causing the pressure to rise and eventually bypass the oring and leak out.

If you need a reg seat... I found a guy selling them cheap somewhere. I bought a bunch and they are great... PM if you want and I'll look for his info.

[athomas]

When you take the regulator apart, you should replace the regulator seat o-ring whether it looks bad or not, especially if it has been in use for a while. Any disturbance of this o-ring from its original position can cause a leak which would in turn cause the output pressure to increase uncontrollably.