Tuning Air leaking rapidly from amp adjustment screw hole

[Noose]

I've read a dozen+ threads but I'm not seeing an answer. I replaced o-rings on my dreamline bullpup power plenum as it was leaking air after a complete degas. On assembly I noticed that the regulator had slipped toward the muzzle end slightly so I worked it backward with a 5mm wrench. I re-assembled and tried to re-air it and air was blowing out of the hole around the amp adjustment screw as fast as my compressor could pump so pressure wasn't going up.

I pulled it apart, pulled the regulator, lubed and replaced both o-rings and it sill blows air out of that hole - fast.

Can it be anything else other than the o-rings around the regulator that caused this all of a sudden? The original orings were flat-sided and there are some mild edges where it looks like it was trying to extrude.

I tried cocking and firing during airing up but that didn't "snap anything closed".

I beginning to hate this rifle.

 

[madeintheuk]

Could be a bad internal oring. That same area is where the reg vent hole vents. If an internal oring has ruptured, it’ll blow through the vent hole, and around the area you’re seeing. I would pull the reg out, and reseal the entire reg. 

 

[Noose]

I just ordered up a bunch of Buna O-rings to give it a go after watching 910's video on youtube. It would have to be a completely blown out o-ring, though, as it is leaking so fast you can feel the jet of air blowing out of it.

 

[2L8]

Noose, If you need an O-ring ( I have many) you don't have, DM me and I will send you a couple if I have them.

Patrick

 

[Noose]

Thanks, Patrick. I spent a few hours reading the fx dreamline basic diagram and ordered every oring that matched the basic. I hope it covers mine but I watched 910's video and my AMP is that exact model so I have all of them coming and since they had a 12 or so minimum, I ended up with a lifetime supply minus a couple of oddball sizes around the valve assembly.

 

[Noose]

The saga continues. I received a box of o-rings from the o-ring store. I bought every size my rifle uses that they carried or had in stock. It seems like The AMP, for now, isn't leaking or at least I can't yet tell. I created a new problem, though.

I now have to assume that this rifle was left in a hot car too many times or out in the cold too many times (or both) as all the the o-rings are flat on the sides and some have very light "edges" that look like the beginning of extrusion. It can't be that old as they introduced the bullpup in Jul of 2019 IIRC. I'm serial number 1919xx

I got to about 135 PSI and it won't fill any further as it has an air leak from the barrel now. I assume this is a valve holder or pin leaking around one of the two o-rings in the diagram. Or perhaps it is loose. Or possibly the delrin piece.

It doesn't appear I have any straight forceps so I'm probably down for another tool.

 

[kball]

Noose,

I'm not familiar with this rifle and do not know what the max pressure is but reading this thread from beginning to end I am thinking it sounds like the air system may have been over pressured? Multiple deformed, bulging and/or blown out o-rings is a clue. Just a suggestion but you may want to check the gauges for accuracy before doing a full fill when you replace the leaking o-ring and re-pressure.

 

[madeintheuk]

Cock the gun before first fill. The valve is probs lay unseated due to lack of air pressure behind it to seal. The hammer spring pressure can be overpowered by the valve return spring and keep the valve open. If you cock the hammer, it puts more spring pressure against the valve to keep it closed. 

 

[Noose]

Cocking didn't seal it up while filling but cocking/firing seemed to do the trick as the rifle is stable now. If it is leaking it is such a small amount as to be imperceptible over a couple of days. Replacing the o-rings in the AMP regulator was easy enough except for the actual tiny air regulator itself. The o-rings on the tiny little plunger were extremely difficult to get to go on. I damaged a couple getting them on -- evening snapping one. The 90 durometer is quite a difference over 70. Now that it is all assembled and leak-free, I'll do a little playing around with the original tune and see where I'm at. I have introduced a small amount of regulator creep which wasn't there before so I suspect the o-rings that I finally managed to wrestle onto the tiny little regulators are still somewhat mangled. I'm going to look for a proper-sized "cone" for o-ring insertion and I'll re-do those. One thing is for sure -- I have learned an enormous amount about this rifle in a very short period of time, lol.

As far as it being over-pressured I assume that is a possibility but I obviously have no way of knowing. Assuming it was overpressured and all of the physical metal bits seem to be OK, what other o-rings are under constant pressure that I haven't already replaced? I'll take a look at those as well.