I don't have any boost leaks ! I have tons of boost ! My Boost gauge says I have 1,000,000 psi boost ! ......

Yep we have heard it all before and I kinda believed it. Figured if I wasn't blowing off boots I was good.

Picked up a 3" PVC pipe cap drilled and taped a hole for a air hose plug. Sprayed soapy water. Bubbles bubbles bubbles. passenger side boot in valley, air intake heater delete plug, drivers side boot in valley, drivers side boot turbo to intercooler pipe.

Curious if I will notice any difference driving it empty tomorrow.

Moral of the story build a stinking boost leak checking device you dummies and use it!!!!!!!

 

Eating crow is not too bad if you can look past the mistakes you have made and learn from them.

Learning from our own experiences and the experiences of others is one of the greatest capabilities we have available to us.

Do you have a boost gauge or are you using TorquePro to read it?

 

Torque pro. I believe the boost reading I have been seeing is accurate. All the leaks were small but a leak is a leak.

Sadly I will have to do it again since I need to pull the passengers intercooler pipe to replace the tube seal for the fuel line to the head.

 

How much PSI can you safely pressurize the tester too?

Obviously, one limiting factor would be the burst strength rating of the PVC plumbing cap.

However, the other, bigger, concern I have is how much is safe for the turbo? Obviously its not really meant to be pressurized at the inlet. Also, the shaft will be spinning with no oil flow.

Its my understanding that sometimes a plenum leak doesn't show up until fairly high boost, so can one achieve a high enough pressure safely, with a boost leak detector, to feel confident that there is no leak at high boost? Can you achieve 30-40psi with B.L.D. without damaging the turbo?

 

The shaft will only spin for a few seconds at most until all the cyliners,pipes ETC are full of air. You won't hurt the turbo at 30-40psi of air.

 

When performing the boost leak test does the system hold air or does some leak through valves?

 

I would assume that there will always be some significant leak down, as you will never get all the valves closed at the same time. Additionally, there is going to be varying degrees of blowby past the rings. How much will depend on the mileage/condition of the motor. So, I think that the turbo would actually be spinning quite a bit, as there will be a constant flow of air, if you want to maintain the pressure.

 

The turbo doesn't spin, the volume of air leaking past the rings isn't enough to spin the compressor. Over 25 psi you risk being hit by a PVC projectile. Don't stand in front of the PVC/ABS cap, it hurts!

 

I have that tee shirt

Clean the oil out of the intake boot and the outside of the Detector well with carb cleaner before tightly clamping in place.

I have pressurized to over 30 with no problems and never had the turbo spin. Have had the engine turn a 1/16 to 1/8 of a revolution as the cylinders balanced out but that's it.

 

I've never witnessed the turbo spinning either and have had the engine turn a tiny bit.

If you lightly score the outer circumference edge of the PVC on the gauge end, you will lessen the possibility of it becoming a projectile without affecting its ability to seal.

Been hit once..

 

Welcome to the club!

The passenger lower boot is a real bear here. I have new billet intake plenums, but even at that, the clamp on the spider side slides and works its way down- even after being tightened fully.

I added one of my old clamps in between the spider and plenum clamp as a spacer to hold the upper one in place.

Add to that, the new super-duper clamps from RRD aren't spring clamps, don't have bent bolts (easier to get bolt into the nut end), and are a little short (hard to get nut threaded when in place.

I wouldn't buy those clamps again. Other than being "new" they are a real downgrade from my OEM Excursion spring clamps.

On top of all of that, like you, I was tightening things up, making more boost and getting rid of leaks. So other weak links start showing up. That's where a boost leak setup is really helpful

FYI. Make sure to put the PVC in ONLY the short piece of tubing from the turbo, NEVER after the CCV, that only throws air into other places.

 

Pics of the problem at that lower boot.





I did mention the short bolts to Clay. As usual, I am the only person in the world with an issue and it isn't worth getting bolts .25" longer

But you can see the challenge there for the clamp and the leak that comes- especially after the boots warm up and get flexible.

Keep an eye on it and check for leaks again after driving it a while

 

I just learned another difference between our diesels and gas engines while reading this thread. A boost leak detector like this won't work on a gas engine due to valve overlap, where the intake and exhaust valves are both open slightly at the same time at the end of exhaust / beginning of intake cycles. Never thought that our diesels do not have valve overlap. Tried searching for camshaft specs for 7.3's but couldn't find anything.

 

John, it looks like the spider is not down far enough for the boot to grab hold of it. I might be wrong, but I am 99% sure that when installing the spider and boots on my truck, there is a very small gap between the hard parts of the spider and the plenum insert. I would say, maybe 1/4" or 1/2" at the most and of course both of those are under the boot.

When you go to reassemble your Ex, see if you can get the spider and billet plenum somewhat flush with each other, then tighten down the boot.

 

Next time the spider comes out, I am going to pull the boot up off the plenum a bit. I shoved it way down on there to start, then there wasn't as much as I wanted on the spider. I didn't realize the length of the boot and how it would fit.

I have a stud on that intake plenum, so the fit is tight and not really simple to do anything with the boot with everything installed. The clamp just barely fits over the boot with the stud in place.

But...the clamp is still above the ridge on the spider, so it *shouldn't* move Maybe it will get better, but I'm not in a big hurry to remove the spider