Or you can spray it w/ soapy water, It will make bubbles where the leak is.

 

only when under boost/pressure

 

Really? why?

 

These threads are the introduction to workin on there first truck for many of the folks readin them, so what may sound like basic common sence at your level of experience may need to be explained for their benefit.

 

ok sorry bout the sarcasm

 

As Uncle Bubba stated, some of these guys are new. When I first started reading forums and wrenching, I would have looked at your post count, along with "chpmnsws6" post count, and normally just gone with who ever had been around here longer. For many of us, this is our only lifeline then starting to wrench on automobiles. That would mean I'd been spraying the intercooler down with soapy water which would have done nothing but cleaned it. Come to think of it, when I had my 1991 Eagle Talon, I did that exact thing looking for a boost leak, because no one mentioned the fact it needed to be pressurized

 

every time i've tried this, all i get is a ton of air going out the exhaust system due to exhaust valves being open. how are you guys buildling any pressure in the intake system when all the air just flows through the head and out the exhaust?

 

All intercoolers leak; they're designed to. That's why they are technically known as "finny leakers".

Cummins procedure for testing whether a finny leaker meets their standards (on an ISB) has two parts.

First, it calls for no more than a 3 PSI pressure drop across the finny leaker under load. I'm sure this spec is higher when you're running twice as much boost as stock.

Second, it calls to cap the finny leaker (PVC works stuck into the existing booties works) and pressurize to 30 PSI (tap a regulator into your PVC elbow). Shut air flow to it once it reaches 30 PSI and it should drop no more than 7 PSI in 15 seconds. Be aware that a piece of 4" diameter PVC with a lot of 30 PSI air behind it can put you in the hospital if it flies out.

Expect to see bubbles with pressure in them and soapy water. It in no way condemns the finny leaker.

 

interesting info. my concern though is more in the couplers, not the finny leaker.