• Welcome to The Truck Stop! We see you haven't REGISTERED yet.

    Your truck knowledge is missing!
    • Registration is FREE , all we need is your birthday and email. (We don't share ANY data with ANYONE)
    • We have tons of knowledge here for your diesel truck!
    • Post your own topics and reply to existing threads to help others out!
    • NO ADS! The site is fully functional and ad free!
    CLICK HERE TO REGISTER!

    Problems registering? Click here to contact us!

    Already registered, but need a PASSWORD RESET? CLICK HERE TO RESET YOUR PASSWORD!

Vacuum test.

JSC

New Member
Messages
8
Reaction score
12
I'm waiting on return plugs for injectors. A gage for the test port. I already had a vacuum tester. I removed the bleeder screw and installed a tester there. I primed it and intel had the gage read 100 lbs. So. Every hour Iooked at the gage it dropped about 10 lbs every hour. Every hose and pump head looked dry. I'm guessing that it should never drop vacuum? And could the. Problem be that's the seal in the tank leaking ?
 
You got 100psi on the supply side!! Nothing about that seems right.

Vacuum test on a no start duramax goes like this.
Cranking 2-4"
It should hold 1-2" indefinitely.
If it leaks down you block off the lines one by one to see if it hold vacuum.
0" means you have a leak and your sucking air. Or a bad injection pump
Over 5" is a restriction in the line, filter or sending unit.
 
Back
Top