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Old Aug 18, 2011 | 01:00 PM
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Question Boost Leak Test Question?

hey guys..
after installing my van turbo, i wanted to do a boost test to make sure all was tight. Got the stuff yesterday and did it this am.
question...i pressured the system up to 15 psi and all i could hear was the air going from my hose to the fitting. when i unhooked the quick air connect the was a rush of air out the leak detector. does this mean it was holding air and all is good, or did i do something wrong. thanks...
 
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Old Aug 18, 2011 | 01:27 PM
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Did you hold the air in the system for long? What I like to do when I do a boost leak test is get a spray bottle of soapy water and spray it on the turbo where it meets the spider, all the boots, and the compressor housing on the turbo. That way if there are any leaks you will see bubbles
 
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Old Aug 18, 2011 | 01:39 PM
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Originally Posted by weekendwarriorfsw32
Did you hold the air in the system for long? What I like to do when I do a boost leak test is get a spray bottle of soapy water and spray it on the turbo where it meets the spider, all the boots, and the compressor housing on the turbo. That way if there are any leaks you will see bubbles
I found simple green to be a perfect liquid to use. Most people have some, and it bubbles nicely. Also, you can use your hand to feel around. You will always have some leaking from the CCV, possibly your oil dip stick and eventually through your exhaust.

Here is a good test. Pump up the pressure to 10-15psi. Disconnect the quick release at the tester and listen for the turbo. You should hear it spool up as the air goes rushing out.
 
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Old Aug 18, 2011 | 02:09 PM
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all i did was set my compressor to 15 psi and just hooked it directly to the cap. i unhooked the filter and put the cap there. it just kept blowing air at 15 psi into the system. is that wrong? do i need to get 15 psi in the system and remove the air supply? i thought i understood the process, but now im not sure??
 
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Old Aug 18, 2011 | 02:19 PM
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Originally Posted by brownie83
all i did was set my compressor to 15 psi and just hooked it directly to the cap. i unhooked the filter and put the cap there. it just kept blowing air at 15 psi into the system. is that wrong? do i need to get 15 psi in the system and remove the air supply? i thought i understood the process, but now im not sure??
What you were doing was fine. But you can also cut the air supply off (Close the regulator) and watch the pressure. If it falls you have a leak. Then try to find it.
 
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Old Aug 18, 2011 | 02:21 PM
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oh ok...ill try that after the boy gets up from his nap. i was just leaving the compressor pump air into the system...what is the best way to cut off the air supply without letting air out?
 
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Old Aug 18, 2011 | 02:22 PM
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Originally Posted by brownie83
oh ok...ill try that after the boy gets up from his nap. i was just leaving the compressor pump air into the system...what is the best way to cut off the air supply without letting air out?
Set the regulator to 0.
 
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Old Aug 18, 2011 | 02:24 PM
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will do...thanks for the info. i dont think its leaking anywhere...but want to make sure
 
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Old Aug 18, 2011 | 02:26 PM
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Originally Posted by brownie83
will do...thanks for the info. i dont think its leaking anywhere...but want to make sure
The boost leak detectors usually only find big leaks, because some will always leak from the motor, (CCV, Oil dip stick, exhaust..). So another way to test is get on a road and go WOT. A stock truck will make about 25psi.
 
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Old Aug 18, 2011 | 02:29 PM
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mines not stock...im making the same boost as i did with my stock turbo...just installed a van turbo. thought etgs are a little high in low rpms, so just wanted to check. also did new up pipe donuts. will a leak detector leak air out of the up pipes?
 
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Old Aug 18, 2011 | 02:58 PM
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No it will not find leaks in the exhaust.
 
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Old Aug 18, 2011 | 03:00 PM
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Originally Posted by weekendwarriorfsw32
No it will not find leaks in the exhaust.
X2 you will need to drive around a bit and look for soot from the up pipes
 
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Old Aug 18, 2011 | 03:25 PM
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I wouldn't pressure the crankcase with 15 lbs of air pressure! I don't think some of the seals would appreciate that!
 
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Old Aug 18, 2011 | 03:31 PM
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Also the intake system won't normally hold pressure. Like the others said use soap and water to check for leaks. Simple green is mildly corrosive so be sure to get it all cleaned off with soap and water! Don't believe me, try it!
 
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Old Aug 18, 2011 | 08:52 PM
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Originally Posted by bulla
I wouldn't pressure the crankcase with 15 lbs of air pressure! I don't think some of the seals would appreciate that!
im not sure what you mean...doing the test, people say set it at 10-15 psi...did i do something wrong?

i actually was able to get it to work...i think...it took a little time to get to 15 psi and then i heard some air leaks...one at the spider to map line and one boot. tightened them up and the gauge held pressure for about 5-7 sec then went to 0..but i assume, thats from losing thru the engine, etc right?
 
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