BT65 Air Cylinder tube not holding air

[JayV21]

Hey All...  My BT65 air cylinder does not hold air.  the valve was worked on by a tuner about 1 1/2 year ago and has worked flawlessly up until last week.  I usually just send my "lovelies" out for power tunes but it's cost me, well, if my wife knew how much I would be living under a bridge.  So, I've decided to start doing my own tunes and repairs.  I have two projects in mind but I'm going to wait a month or so before I take them on.  For now, I'd like to repair my BT and staring showing it the affection it deserves.  It's an elite .177, and the air cylinder I'm using was originally from a .22.  the valve ports have been plugged except for two.  Any ideas?  SOS, HELP PLEASE......

[Kmanca1]

There can only be two causes.  it's either an O-ring has gone bad, or there is dust in the fill port.
MINE had the speck of dust in the fill port.   

If yours is like mine......you're SOL.   It will be much easier, less time intensive, and cheaper in the long run to just get a new tube.
Once you have the new tube, swap out your modified valve for the new stock one and you'll be back in business. 

[JayV21]

Thanks.  I'll give that a shoot. 

[Privateer]

Put the tube in a bath tub with some water and you will find the leak real fast.
Just be sure to dry it really well to prevent rusting of any steel parts.
The tube is aluminium so that won't rust.
HatsanUSA has the rebuild kits.

Swapping the valves can lead to a misaligned port job. But since you have 2 holes open it shouldn't be an issue.

[JayV21]

I'll give it a shot. Thanks.  If i can't it get going, who would be able to repair it that's in the Midwest area?  I've spent a fortune just on freight to the west coast.

[Privateer]

You in Illinois?

[JayV21]

Yup.  The communist state of Illinois!

[Tundra]

I've fixed my bt65 air tube twice. First time I pulled the probe before it was bleed off and damaged the o-ring. They give you extras when you buy the gun. Take a chunk of two by four and a hole saw and drill a hole as close to the tube size as possible then run it through a table saw and cut it in half. This will hold the tube in a vice without marking the tube. Has to be tight in the vice. Now take a big screw driver that fits the probe fill hole and unscrew the end. It's tight so be careful when it lets go. Hit myself in the face the first time I did this. There are videos on u- tube as to how to take the o- ring out. Basically when you take the end off the back comes off and you will find the o- ring. Be sure to wet the new o-ring with grease or it won't be long and you will be doing it again as I had to. That was months ago and hasn't leaked since. Good luck on your repair. It's not very hard to do. Hope this helps.

[JayV21]

Fixed.  Found a bad oring on the valve.  Not hard at all. Thanks for all your help. Next is the AT44 cylinder.   Maybe later tonight or tomorrow morning.  I did look on the Hatsan website for the rebuild parts.  23.00 for a hand full of Orings??   I found that to be shady.

[otter5555]

i get ALL my orings at the parts store for about 5 cents each and they work perfectly