Thanks, I did give it a basic test using a Mityvac, a bit of flat plastic packaging and a liberal coating of vaseline. I could apply a vacuum of 60mbar/17 inHg and it would hold vacuum for about 15 seconds. I also filled it with water and left it overnight and no leaks. Given the crude test setup I think it is probably ok to put back in, but if you can suggest another test method I'll give that a try too. Where did yours leak from?
