How to test for boost leaks??

[JonEQuest]

I have made up a rig to test for boost leaks but I can't get it to hold any pressure.
What I made was basically what I have seen others do online. I have two PVC caps. One cap is in one inlet just capping it off. The other is in the other inlet and plumbed with an air line T that has a air pressure gauge and a hose to input air. I have that hose run to a air blower nozzle so I can trigger air in when I want to momentarily. I have pumped air into the system and I was able to use soapy water anf found a loose V-band clamp on the front turbo and another small leak around my map sensor o-ring. I have fixed both of those but when I add air the pressure gauge stays at 0 psi. I was hoping to be able to pressureize up to about 25psi and look for the type of leaks that arise during full boost. I cant seem to get pressure to build. One thing I observed is that when I turned my oil cap it was definitely under presure and popped off when I turned it open. I have an external PCV setup with low and high side catch cans. Should I pinch off the hoses to the catch cans to stop air from going into the crankcase? The videos I have seen online people seem to be able to pressurize the inlets and outlets and it holds pressure for a little bit.

 

[sosiiick]

Try finding a smoke machine. I have had good success finding boost leaks with one.

 

[JonEQuest]

Try finding a smoke machine. I have had good success finding boost leaks with one.

I bought a smoke machine but it didn't really put out enough smoke to show anything. Plus I want to be able to pressurize the system to find leaks that happen under boost. I did get enough info with soapy water to find leaks and seem to be able to boost up to 20psi but I am sure my turbos need to make 23psi to keep that up.

 

[Pete]

If you can't get access to a smoke machine, use a air pressure regulator and plum it to the intake system and cap off the inlets. A cylinder leak down tester set to under 15 psi makes a good high pressure smoke tester. You just need soapy water because there is no smoke. Usually you can just hear the problem.