Found an air leak! :-( Now what?

[Donnie]

Still building the GT186 slowly and done a leak down test

It's hard to tell though exactly where its coming from? ie its looking like its coming from the upper cylinder stud on the mag side.
However, it's not coming via the base it's between the 1st and 2nd fin.

So, is it a leak via the stud and travelling up past the base gasket to the next spot and fixing it simply means removing the stud and replacing with loctite added to ensure no leak or is there something else going on?

Any help appreciated.

https://www.youtube.com/watch?v=gWxEDSZ_VCg

[Captain Pugwash]

You dont need to test above 8psi some test kits advise no higher.

Check the alloy around the barrel stud for damage if it's ok then likely it's the seal between the barrel and your engine case this is allowing air to travel from the primary chamber across the gasket face and out into the barrel stud hole thats where you can see it escaping between 2nd and 3rd fin.

[dave411]

Have you used any type of sealent on your base gasket?

[Captain Pugwash]

Have you used any type of sealent on your base gasket?

I don't often use a base gaskets, but if I do I use loctite 5922 gasket dressing.

[Donnie]

just greased the gasket as I usually do to be honest.

[Wack]

Most of the gaskets are crap nowadays so I try to avoid as they split around the stud holes when the cylinder is torqued up.

[Donnie]

This one was a reasonable one, ive had to take it apart, reseal everything again using some threebond liquid gasket but it's still got a leak but not as bad so im on the right track, im going to have to replace the stud and use some threadlock just to eliminate that I believe.