Discovery still leaky.. (Gauge fitting)

[FOZZD1]

One gun perfectly sealed and then onto the 2nd. Thought great its all done but after a while the pressure had
dropped on the 2nd one.

After some testing it turned out to be a very slow leak where the gauge screws into the small extension piece.
Removed the gauge and cleaned the threads, finger tight and a little nip. nope still leaking. Nipped it up
some more and it still leaks. Seems to had a spot where it leaks more like its oval.

Seems to be a taper thread and stumped what to do now. Gauge seemed to sit way deeper than the first gun
so I shaved 1mm off the length of the spacer piece but still the same leak.

Any tips?

Thanks

[Phil Russell]

I don't know the Benjamin Discovery but looking at a parts diagram there appears to be an O ring (?) sealing the gauge? Could this be faulty?
Cheers, Phil

[--ped--]

have you done wet leak test i dump the tube in water if i know i am stripping again or soapy water spray
you can also spray with wd40 but i find it doesn't always show slow leaks as well
the gauge can be a real pain to seal and i swap it for a reg or fit the later p-rod block and gauge

[FOZZD1]

Not making myself clear again lol. I really should read my posts back before clicking submit.

On the Discovery there is a steel spacer piece with an O ring small lip locates the rubber ring and screws into aluminium so very little
pressure is needed for that. I tightened that finger tight then a tiny nip with a spanner. Sealed perfectly.

The gauge screws into that steel piece with a tapered thread, its 100% leaking from that joint. I tightened it to a point where I thought
any more and its going to snap.

Something amiss I think, tighten it ans there seems to be points where it leaks more in one orientation than others.

Its like the threads are oval, or there is a high point that causes it to leak worse when it rotates to that spot.

Totally leak free from everywhere else.

Just picked up some thicker PTFE tape 0.2 rather than the 0.75mm if that fails I will need to recut the threads or add spacers and seals
I think.

Thanks.


PS.
Yes wet leak test in a bucket, not a single bubble from anywhere else. And tested at full pressure also because I thought it was fixed but
only sealed with very little pressure.

[Phil Russell]

Thanks for the clarification. More comments but again most likely rubbish:

Can you detect exactly where it is leaking from? Is there any chance someone has screwed a gauge in too tight and cracked the housing? Is it the correct gauge?

Can you try a few winds of PTFE tape ... I note you intend to and it would be interesting to see the result.

If you compared the two rifles, what differs in the gauge/housings? Could you try the other 'good' gauge in the problem housing? And vice versa?

Cheers, Phil

[FOZZD1]

As I tighten it the leak gets better then worse then better then worse. Threads are not stripped and it tightens far more
than the 1st one needed. I have cleaned the threads several times over and still it leaks.

Wrapping the 0.2mm PTFE tape around it now. Wondering if a full 5 metres is enough.
5metres of this fills the reel where it takes 12metres of the thinner stuff.
Handy stuff to have in the toolbox maybe?






Thanks