Can Leaktest be done on Vacuum instead of pressure?

[chee_dee]

I am in the process of fabricating my own leak tester. It is extremely hard to find a Pressure Gauge that reads in the 7Psi range. Only one I found so far is for a Brake Vacuum Tester, but it reads vacuum.

Question is, will 7 PSi Vacuum work the same if I go in by the plug whole? Surely this would suffice unless I am missing something.

Any input appreciated.

TIA.

 

[Awk08]

I do know someone who used vacuum instead of pressure, not sure what amount of vacuum he used ? MBAR or HG ?

 

[chee_dee]

Surely the same amount as per pressurizing it? 7PSi?

 

[Larry's Shee]

Only problem I can see if it doesn hold you still can’t tell where it’s leaking

 

[chee_dee]

Ahh.. that makes sense yes. I will try it... if there is a leak however, I will have to do it the other way around.

Thanks @Larry's Shee