PP700 leaking. Common spots?

[kcatx]

It seems my PP700 is slowly leaking, drops about 5 MPa over night.
Where do these things usually leak from?   I'll go at it with some leak detector at some point soon but was wondering if it may be somewhere internal that I won't be easily able to detect.

[nervoustrigger]

The OEM O-rings in mine were a problem in multiple areas but from what I recall of the mammoth GTA thread, the two most common spots are the fill port O-ring and the regulator body.  Be advised the regulator body seal I’m referring to is not an O-ring, it is the crush seal formed by squeezing the daylights out of the white plastic washer inside.  A simple workaround was published early on that shows simply dropping an O-ring into the space surrounding the plastic washer, and that does indeed stop the leak but it introduces a new potential issue which is that the air now trapped inside can work its way to the low pressure side.  That behavior shows up as regulator creep (a slow or fast first shot after sitting idle for a while).  Bonding the washer down with Superglue is a solution.  A lot of folks threw their hands up and bypassed the OEM regulator and installed a Huma in-tube regulator.  I’m too stubborn.

[kcatx]

Thanks nervoustrigger.  I  may take a look at the fill port O-ring, but won't mess with the regulator-- unless I'm going to just pull it out and put in a Huma.  I've let it sit from posting until now and it's only down to half full, so it doesn't appear to leak beyond that.  That isn't a big deal to me as it still shoots full power at that rate, so I'll probably hang tight until the 750 is available...

[kcatx]

Well, I apparently let it run down too much.  Now when I attempt to fill it the air comes right out the barrel.  I assume the value isn't closing (maybe dusty now?) and a Huma reg would be the ideal fix?

[denovich]

It could be a leak in the valve body. Maybe try a soap bubble on the transfer port. I got some debris in my valve that made a dent on the plastic sealing surface allowing air to leak by. The damage to the surface was hard to see without magnification. I solved it by chucking it in my drill press and using a file to remove enough material to remove the dent.

[Back_Roads]

Well, I apparently let it run down too much.  Now when I attempt to fill it the air comes right out the barrel.  I assume the value isn't closing (maybe dusty now?) and a Huma reg would be the ideal fix?

 Have you tried filling with the gun cocked ?

[kcatx]

  Doh!  Of course not!  This happened a few days ago and during the interim I remembered that for various guns this is the first thing to try,  then promptly forgot that and posted my follow up when I saw the gun again.   As soon as I saw your message I realized I never *actually* tried that, so just did.  Problem solved!
 Pure idiocy on my part!   Thanks for calling it out so I could double check!  I guess now I'll need to come up with another ploy to get a Huma reg :-)

Have you tried filling with the gun cocked ?