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klmnla

Watson LA
Joined
Feb 22, 2008
Messages
370
I decided to air test my intake with the gadget below. I was about to change the valve springs, so decided to test while I had the rockers off and the valves closed. Its amazing how many leaks that cant be detected just while the motor is running. 4 out of the 5 small vacuum hoses on the vac block leaked under pressure. I now have an air leak on both sides of the throttle body at the shaft seal, near the return spring etc. Im not sure how to fix that one? Either way, once the seals don't leak and I have the new valve springs in, hopefully I will have this ongoing problem fixed.
GN intake air tester.JPG
 
Thanks, I ordered the seals last night. I guess I will change out the valve springs while waiting for the parts to deliver.
 
tell me more about that gadget and how it works. See it in another post thanks.
 
tell me more about that gadget and how it works. See it in another post thanks.


Its pre-made to fit on the 2 -1/2 inch TB opening and has an air valve. got it from silicone intakes on line. Makes it easy to pressurize the intake and discover all those darn leaks.
 
So once you pressurize the intake how did you determine where the leak was coming from. Can you feel the air coming out or was there anything else you did?
 
So once you pressurize the intake how did you determine where the leak was coming from. Can you feel the air coming out or was there anything else you did?


I would hear the air leaking, and then would run my fingers near the sound until I actually felt the air. I also sprayed a little dish detergent mixed with water and looked for bubbles. All of the vacuum hoses on the vacuum block were fairly new and tight fitting, however 4 out of 5 leaked as soon as they saw a little pressure. Im going to zip tie every single one of them. And the TB shaft seals leaked really bad. GBody has the seals for $20.00, and I ordered a set. I will check for additional leaks, like the EGR block off plate etc as soon as I get these items fixed. Valve springs go in this week also. Good time to do them, since the rockers had to come off anyway.
 
Forgive my ignorance but do the valves need to be closed to use this? Im fighting getting my settings correct and i am planning on putting all new vac lines on when i find a kit (anyone know of one) and then testing vacuum but i didnt know how until now. I also didnt know about those throttle orings that may be part of my issue.
 
Forgive my ignorance but do the valves need to be closed to use this? Im fighting getting my settings correct and i am planning on putting all new vac lines on when i find a kit (anyone know of one) and then testing vacuum but i didnt know how until now. I also didnt know about those throttle orings that may be part of my issue.

Yes, the valves have to be closed. All my vac lines were tight, or so I thought, and spit out air with less than 20psi in the intake. I can imagine what the leak were like under boost. I was told the TB o-rings will leak a little, but mine leak really bad. Mostly because i tried to replace them a while back with some rubber o rings and they did not seal very well.
 
alot of times the nipples on the billet blocks leak , they should all be removed coated with loctite and reinstalled tight

personally i dont like the spacing on the billet blocks to get a good seal , i klnow its stock appearing but the seperated port vac blocks that take 1/8 npt fittings are much better suited for performance
 
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