i took an old glow plug and brazed a pipe onto it with a 1/4"npt chuck.

the gauge is a diesel gauge and has a release button and i believe a one way valve in it.


But it isn't working i hooked it up and cranked it over and it goes right to 300 but as soon as i stop cranking it's down to zero.


The check valve must be bad or it needs another one lmaybe lower?? Funny thing is if i shoot com pressed air into it with a blow gun it holds at 150psi??

 

Something must be wrong with the gauge's check valve. Maybe the check valve can't hold the 300 but does ok with the 150. What is the gauge rated for? Got a picture of your set up? Your handy tool sounds interesting, Might make one..

 

it's a motorite head. they're made in USA out of pittsburgh by bacharach they make Hvac stuff but they stopped making they got out of the auto tools business. I figured it would be better than spending the money for a cheap china one.

Anyway i think i found my problem. the gauge has the button on the stem below it i thought it was a check valve but i think it's just a release valve to release air in the hose. but it hold air in for the small stuff. Maybe it is a check valve i don't i ordered one of the chinese ones off ebay.

the problem is i think the check valve is in the fitting with the quick connector. the Motormite use a different set up which i didn't get.

also all the compression testers use a 1/8" npt quick coupler and couplings can't find that stuff anywhere. everyone thinks i'm on drugs when i tell them i want a 1/8 npt quick coupling.

I found check valves in 1/4 npt but they almost as much as the chinese testers so i'm just going to buy a chinese one. maybe the barach motormite head will fit in place of the chinese gauge.

 

The cell brass. close nipples with check ***** built in.
Just put one of these inline with your gauge. Cheaper