TargetTalk

I have one of these Tau pistols we use as a club loaner. We have precious little junior size pistols so this gets used quite a lot. Recently started leaking CO2 through the valve. With action open it leaks through the hole in top of frame. I've tried pelgun oil which usually fixes everything. Taken grip off, remove rear of action screw. Removed piston seal and white seal. All looks okay but that is as far as I've taken it down. Someone send a link showing exploded view and let me know where to source parts. These are pretty simple machines and I'm thinking there is something I'm missing.

Anyone have one of these sitting in the basement they want to sell reasonable (better yet donate) to our club?

It sounds like the firing seal is leaking, which can be a pain in the neck to repair. Parts can be obtained from Tau Brno in Czechoslovakia. The best exploded diagram is here:

http://www.74fdc.files.wordpress.com/20 ... ploded.jpg

The parts you are interested in are #27 & 28. Sometimes just cleaning & greasing the seal area will do it. Dirt can get embedded in the plastic seal surface. Depending on how you use it, one problem you can get is condensation from venting the CO2 quickly. This can cause rust, both on the face of the metal valve, and inside the chamber in the grip. When the rust flakes off, it can get embedded on the plastic seal surface.

The plastic seal is a press fit, and can be a royal pain to extract. The early ones had a steel sleeve inside that can make it even trickier.

If you have to replace the seal, let me know, and I can try to cobble together all of my notes on how it's done. Alternatively, I suspect Buck at Pilkington can do it for you.

As you describe it, you already removed the problemseal; the valveseal. Its a pain to get to as it lays deep in the pistol.
Iirc, there are 2 seals, blue and white. I believe the blue are more recent and softer.
Tau's work so well in a variety of temperature because of hard seals.
It sometimes helps to tap the valvestem into the seal to get it to 'fit'the seal and seal off.
If this doesnt help, you'll need replacement.
A surplus of oil will only make it leak not cure it.
Parts can indeed be ordered directly on the Tau website.
Charish yr Tau 7 jr ; they're awesome pistols and the Jr's are very rare, expecially the older types