How to test for turbo hose leaks???

[LarryB]

Just returned from a recent trip. Comming up the Vantage hill in eastern WA I was making good time and 25psi boost when I heard the infamous POP-Hissssss followed by black smoke and high EGT. I pulled over and reconnected the blown off right rear boot. After getting back on the road I discovered that I now could make 32PSI and the EGTs were relatively lower. Seems that boot has been leaking for a while.



Question:

How does one test for leaks this side of riding under the hood while pulling a hill?



I'm thinking of making a set of plugs for the turbo inlet and outlet so I can pressurize the entire system to check for leaks. Is this the way to go??

 

[Shovelhead]

Another member posted about building a pressure tester a year or so ago.

Seemed to work OK, but posted the next day that one end of the tester blew off while testing, smacked him in the mouth and broke a tooth.



Be Careful.

 

[nickleinonen]

the easiest way to measure/test for any leaks would be to have 2 boost gauges. one pre IC, one post IC. tap one straight off the turbo elbow and one in the intake side. make sure everything is nice and tight. and then get some baseline numbers to record so you know if the numbers go way out of sync, time to fix 'em quick



am i completely off here? or would this work well?

 

[illflem]

nick, the pressures would be the same even with a leak. Imagine the boost system as a tank, the pressure will be the same no matter where the reading is taken.



You can make a tester by tapping a 1/4' hole in a plug inserted into a 4" ABS coupling. The coupling will fit on the boost hose turbo connection, put an air fitting into the tapped hole. Keep the pressure under 25 psi so you don't lose a tooth and apply soapy water to potential leak areas, don't forget the intercooler.

 

[LarryB]

Bill

Do I need to have the engine in a certain position so the air doesn't blow through the engine because of valve overlap? I figured I would need an exhaust side plug too.

 

[illflem]

Larry, I never have but have a high cfm compressor. Have had the engine land on a spot where the valves were open just right, the escaping compressed air actually turned the turbo till I bumped the engine. If too much is escaping for your compressor or you don't like the noise just make a plate out of rubber, plastic or whatever to sandwich in-between the air horn and manifold.



I got to thinking and am not totally sure if the fitting I used was 3 or 4" or the outside diameter of pipe or fitting, do remember I used it to fix a plumbing leak later. Better check before you tap.

 

[QRTRHRS]

It's 3" pipe. I used some really heavy wall scrap from work to make mine. I had to spray a little WD for the pipe to slide into the hose. I must have missed the correct valve position until I gave up. Going to make a cap for the intake end and try again.



Don't forget to inspect the o-ring between the turbo outlet and the cast elbow. I forget the size.

 

[JMarkos]

I built a plug out of aluminum that gets clamped to the elbow coming out of the turbo and made a plate to go between the grid heater and the intake. Brought it up to 34 psi and closed the valve on the compressor and let it sit for 20 minutes or so ,lost about 3 pounds, I'd say that is pretty air tight.



However I have moved my boost gauge from the waste gate hose to the intake and have lost 6 psi at full boost, which I am not sure there should be that much pressure drop but I sure can't find a leak. Beats Me???

 

[Doc Tinker]

Try this: Get some sticky liquid soap (there is some long lasting kids bubbles available) and soap up the connections. Take it for a short drive under the conditions that you describe. Pull off on the shoulder at the end of the pull, pop the hood and see if there are some bubbles on the connections. I'm just guessing that it would work. Maybe you could loosen a clamp to make it leak and try the bubbles to see if it works.



Doc

 

[JIM S.]

if you had an old motorcycle intertube, cut it and hook the ends to the metel pipes and pressure it up to 10 PSI or so and if it holds it good if not get soapy water and start spraying away.

Jim

 

[Champane Flight]

We use

We use dish soap and water. It really does not take a lot of pressure to detect leaks with this mix. I would just idle the engine, or maybe bump the throttle a little and spray the affected areas. Should show up.



Or use the same solution and a rubber sewer cap on the filter side, pressure with compressed air from the boost fitting. You might have to roll the engine over a little to get on TDC. But any leaks should show. Make sure you use a regulater on the air, as you don't want to blow boots.