S410 still leaking

[Hairybiker59]

I stripped and replaced all 0-rings on my s410 because it had a slow leak.i replaced the o ring on the pressure gauge for a dowty seal tightened it up and filled rifle.all was well until the next day I noticed it had lost air,I put a balloon over the pressure gauge and it inflated it.it the problem the dowty seal and should I replace it with a o-ring?

[ronnie12342003]

or the pressure gauge is nacked

[TenMetrePeter]

Dowty seals are designed for flat faces without a groove. The dogleg will have a groove for an o-ring to expand into but the dowty lip may actually drop in and not be compressed. I would go back to the correct size o-ring

[Hairybiker59]

Dowty seals are designed for flat faces without a groove. The dogleg will have a groove for an o-ring to expand into but the dowty lip may actually drop in and not be compressed. I would go back to the correct size o-ring

I believe that the dowty seal was at some point used on the s*series but not sure if it was the older or newer models

[Brooksy]

If it was designed for an O ring, fit an O ring. Apply a tiny coating of O ring grease first, this helps it to seat correctly.

[TenMetrePeter]

Also depends on where the balloon was fitted. If only on the gauge body then it may well be the gauge bourdon tube knacked as already suggested by ronnie

[TenMetrePeter]

Screen Shot 2017-04-25 at 14.18.20.jpg (20.17 KiB) Viewed 5746 times

If the dogleg looks like this with a groove milled into the face where the gauge threads then it deffo needs an O ring.
If it is completely flat with just the thread then a Dowty washer is indicated.

[Hairybiker59]

Removed the dowty washer and replaced with an o-ring,filled to 100 bar and left it overnight and all is good.happy days