valve problem for 68 classic

[Chozy]

I just bought my 68 automag last week on e bay its a used one and it has a problem i dont know how to fix. When i screw in the co2 tank all the co2 does is shoot out of the back of the gun and makes a sqeeking noise. What should i do to solve this problem do i need a new part? Thanks

[mcveighr]

Turn down the velocity, if that doesn't work, check the reg seat o-ring. Thats the brass int in the back half of the valve.

[athomas]

Whenever you get a new mag, you should take the valve apart and clean it. Check all the o-rings and replace any that are worn or damaged. This is a good chance to inspect the valve and apply a bit of oil. When you put the valve back together, put the CO2 on and dry fire a bit to blow out any excess oil.

[Chozy]

again

Well for the most part that worked. I unscrewed the bolt on the very back and put in c02. The gun did not leak but there was very low velocity. When I turned the velocity up it began to leak out the front of the gun, and not even reach the valve. After that, I loosened the bolt to find that it was still leaking. I've replaced all the O-rings already but still dont know what to do...

[athomas]

Make sure you don't point the gun and CO2 towards the ground when you screw on the CO2 bottle. This could cause liquid to flow into the mag. This will freeze the o-rings and CO2 will flow throught the gun.

With the gun pointed up, screw in the CO2 with the trigger held in. Sounds awkward but easily done. Now, check for leaks. Hopefully none. If there are leaks, note where they are coming from. Any from the front or bottom would be caused by a leaking on/off assembly. Leaking from the back could be caused by a regulator seat o-ring or an o-ring around your regulator assembly. If there is no leaking, release the trigger quickly, listen for leaks. Any new leaks will be out the front and will be caused by the powertube o-ring.

Usually, gas shooting out the back of a standard valve is caused by the regulator seat o-ring. If the gun is used, you should replace it, especially after you have had the gun apart. Older reg o-rings never seem to seal well after that.