Rebuilt valves aren't happy

[jpdgas]

Long post for what I really hope is a simple fix, so here we go!

I have a RTvalve and Xvalve in two separate guns that are having the same after rebuilding them. They had 20yr old orings so I replaced all of them.

Both the RT and Xvalve have the same issue regardless of which gun they are in:
When I hold down the trigger, there is a diminishing leak down the barrel. It starts out strong, and dies down in a few seconds, but never goes away. Then after 5s or so, the gun starts trying to shoot and chuffs. So, trigger pull, fires, HISSSssssss...chuff....chuff...chuff...

What I have tried:
Fired 100+ to break in orings
Flipped on/off orings in case they aren't seated
Stripped the valve down all the way and re-cleaned surfaces and orings, oiled each oring on assembly
Tried various carriers, the current is the largest that doesn't leak, which is the single dot
Tried various velocities
Swapped on/off assemblies between the RT and X
Swapped valves between guns
Tried a 800psi and 1000psi tank
Cried a little, swore a lot

I don't know what details are pertinent, so here is everything I can think of:
Both are running lvl10, red spring, and the largest carrier that doesn't leak down the barrel.
Both are on a ULE frame, new sear, Intelliframe and ULE body
Xvalve is using a Lukes trigger, RT valve is the intelliframe trigger
Velocity for both is 285 +/-5

Secondary issue with the Xvalve, it sprung a leak from the regulator side hole before the rebuild. After the rebuild, it has mostly resolved itself after shooting it a bit, although occasionally there is a slight sputter from the hole.

Thanks in advance!

[rawbutter]

Sounds to me like the problem is in your on/off assembly. Maybe you got some bad o-rings in your parts kit. I've had that happen to me.

If you email AGD, they might send you a few replacement o-rings for free, especially if you just bought the parts kits.

You did change ALL the o-rings, right? Sometimes guys don't change all of them because a few are hard to replace, or they don't look worn. Sometimes you get lucky, but not always.

[superman]

Sounds like your top inner on/off oring.

[jpdgas]

Yep, replaced every oring in each valve with new kits from AGD. I flipped all of the orings in the on/offs but it didn't make a difference. Maybe a bad batch?

I have reached out to Sandman as well.

[nak81783]

I’ve always had good luck with theoringstore.com

The “millable gum” urethane EU 90’s work well, but maybe don’t last as long as the cast urethane.

They even have the single turn split washers that go on the reg pin.

With the minimum buys, it’s probably more up front than a parts kit from AGD, but you’ll get more rebuilds from theoringstore.com’s min buys.

Also, I’d strongly recommend using gold main springs. Unless you’re actually breaking/chopping, any stiffer spring just further complicates the system.