Classic RT problems

[GTC1187]

I picked up a classic RT but it has a slow leak from the rear off the marker. I have a parts kit somewhere, is it likely just an oring?
Also, the original twist lock barrel will turn 360 degrees when fully inserted. Any ideas?

[Nobody]

Check the reg seat. Make sure it is clean. If it is mishapen or gummy, replace it.

The twistlock, check the barrel pin. Sounds like it was pushed down and either the spring is broken or it needs to be tightened.

[athomas]

First thing to do when you aquire any new gun/mag is to clean the entire valve and gun. Replace any suspect orings.

When the marker is leaking out the back, does the velocity seem high? Turn down the velocity and see if it helps.

If the leak goes away, then your problem is due to the regulator piston assembly venting excess pressure. It isn't a problem unless it vents at too low a pressure such that you can't reach the desired shooting velocity.

If the leak goes away but the velocity is too low, then your regulator piston assembly is too weak for your setup. This usually happens with older regulator piston assemblies when used with higher pressure level 10 volt systems. If your mag is running a level 10 bolt and still has the original regulator piston assembly, then this is probably the source of the leak.

If the leak persists and the velocity is still high after you turn down the velocity adjuster, then your regulator seat oring is dirty or bad.

If the velocity adjusts normally, the leak out the back seems to always be there, then the oring around the regulator piston assembly is probably bad.

If the twist lock barrel rotates 360 degrees, then the twist lock assembly isn't working properly. Either it is missing, damaged, the tension is set too weak, or the grooves in the barrel are bad.

[Cyco-Dude]

where exactly is the leak, do you know? is it coming from the hole in the regulator adjustment nut on the back of the valve, or just somewhere "in the back" that you can't see? i would check all of the valve and banjo bolt o-rings as athomas mentioned...pretty standard stuff for a mag, especially an rt classic. every one i've got needed a valve rebuild lol.

[athomas]

Yes, I assumed the leak was actually coming from hole at the back of the valve, which is the velocity adjuster.

If the leak is from somewhere at the back, but not the velocity adjuster hole, then you need to identify where it is actually leaking first. Then, its usually just a simple oring fix.