Dreaded ATS OEM Turbo Up-pipe slip joint leak has killed my boost 2022 edition.

[ocnorb]

On my last camping trip I was loaded up with the cabover and had our enclosed car hauler trailer filled with toys and gear. Truck seemed to be running ok until I started up the first of a series of canyon passes. Up the first canyon I was only seeing about 4.5psi of boost where I normally get 8.5-9psi. (Stock 1994 IDIT with factory turbo and pinched downpipe and intercooled. Waste gate wired shut.) My EGTs were also higher than normal.

After refueling at the next town, I headed up another long canyon with a few steep spots. Now I only had 2psi of boost! I didn't dare stop as it was narrow and I didn't know if I'd be able to even get going again. I made it to the top and the dirt road to the campsite with no issues. Next day I popped the hood to investigate and decided to check the t-bolt clamps on all the IC tubing. I found the t-bolt on the intake snail was stripped, so I took it off and replaced it. This brought me back up to 5 psi, but no more than that.

Yesterday I had some time so I replaced all the 2" t-bolts with Murray Constant tension clamps. Took it for a test drive up a local hill loaded with just the camper. It was definitely spooling earlier now, but still not much over 5.2psi on the boost gauge. I played with the timing and made the same run a few times. Retarding the timing a sliver did improve the bottom end, but still only 5.1psi of boost up the canyon.

I returned feeling a bit defeated. Crawled under the truck and found this:

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Spent a few hours reading all about it. Sounds like Russ had some NOS parts at one time, but they are no longer. I saw on FB that Grilli was making up-pipes, but has turned it over to R&D. I could not find anything about it on R&Ds site. Also nothing on Classic Diesel Designs except a used set that has already been sold.

I have a few questions for anyone wiser than me:

1. Would it be possible to make a copper gasket that could be set up in the top of the bell area?

2. Could the bell be brazed with copper/silicon brazing that was soft enough to deform and seal when the y-pipe was put back in?

3. Does a leak that small really cost us 4+ psi of boost?


I need/want to do the 3" downpipe at the same time. Popping $1350 for R&Ds manifolds/up-pipe and turbo mount setup has crossed my mind. I'd like to do a few upgrades in the near future and have been collecting parts/ca$h to do them. I have head studs ready to go in. I just ordered a larger IC setup that will require some changes too.

Thanks in advance for the answers/advice/ribbing, etc.

 

[Nero]

Turbos spool up from heat expansion from the exhaust. If it's leaking out before the turbo... No spooling means no boost.

I recently installed a 093 kit on my truck, and Wes at CCD suggested using hi temp orange RTV on the slip joint. Permatex 81878 is what I used. Globbed it up a lot in that joint, pulled my camper and boat with full truck 400 miles no leakage at all.

You'll have to wire wheel the joint up to get all the soot and carbon out though, so the RTV will stick.

 

[ocnorb]

Turbos spool up from heat expansion from the exhaust. If it's leaking out before the turbo... No spooling means no boost.

I recently installed a 093 kit on my truck, and Wes at CCD suggested using hi temp orange RTV on the slip joint. Permatex 81878 is what I used. Globbed it up a lot in that joint, pulled my camper and boat with full truck 400 miles no leakage at all.

You'll have to wire wheel the joint up to get all the soot and carbon out though, so the RTV will stick.

Many of the threads I read indicated that the RTV often failed; has anyone had it work for 20k+ miles?

 

[Nero]

Yeah I've only got about 2k on it so far, eager to hear what others have to say.

 

[IDIBRONCO]

If all else fails, Idioit makes and sell a new pipe to eliminate that joint. A copper gasket may work in your situation if you can get it to the right thickness. We have copper washers/gaskets that seal the bottoms on our injectors and there's A LOT more pressure there than at a turbo up pipe.

 

[YJMike92]

I have thought about putting a coat of braze on the male and female sides and pressing them back together to increase the clearance, but have never tried it. I'm not sure that would be worth trying.

 

[ocnorb]

I have thought about putting a coat of braze on the male and female sides and pressing them back together to increase the clearance, but have never tried it. I'm not sure that would be

If all else fails, Idioit makes and sell a new pipe to eliminate that joint. A copper gasket may work in your situation if you can get it to the right thickness. We have copper washers/gaskets that seal the bottoms on our injectors and there's A LOT more pressure there than at a turbo up pipe.

I was hoping to this thread might shed some light on wether or not someone has tried the copper o-ring/gasket or even brazing a soft material to the bell of the y-pipe. Lots of guys have run up against this and most are more clever than me. The collective knowledge here about IDIs is astounding.

If I could pull the y-pipe and braze it or make a copper gasket that works is far less work than installing a new up pipe.

 

[IDIBRONCO]

My opinion is that you would have a worse leak if you tried the brazing unless you could get it machined to be smooth. I think that a copper gasket/crush washer would work better.

 

[ocnorb]

Well, after lots of looking I found an industrial product that just might be the ticket to fixing these leaky downpipes.

Highest temperature rating for any RTV product I found was 750F. I think that it will work for a little while, but we know these joints are seeing 1200F and maybe more at times.

Stumbled upon Deacon 8875. It’s used in sealing high temperature and pressure turbines and industrial flanges.

It’s rated to 1800F and 5000psi after it’s cured. Data sheet says it’s for “low tolerance metal to metal joints” and “unaffected by thermal cycling”. In addition it forms a “mechanical type seal”, it expands as it cures and does not cement the metal together so later repairs can still be done.

I ordered a tube and I will give it a shot.

 

[ocnorb]

Deacon 8875 info sheet

 

[IDIBRONCO]

It sure sounds promising. Maybe you stumbled onto a real treasure.

 

[Booyah45828]

Well, I hope it works out. It also has a cure time, which needs to be 300 degrees minimum at atmospheric pressure for 2 hrs. I'd start the truck and let it idle for 2 hours, maybe take it on some light driving afterwards to get the temp higher and a better cure?

Wes said a few times here to use the copper permatex. I know some guys have used copper never seize. I think both require an interface that is on the tighter side to work though. If your slip joint is loose, I'm not sure what to tell you. Maybe try furnace cement? It's also available in a caulk tube.

 

[ocnorb]

Well, I hope it works out. It also has a cure time, which needs to be 300 degrees minimum at atmospheric pressure for 2 hrs. I'd start the truck and let it idle for 2 hours, maybe take it on some light driving afterwards to get the temp higher and a better cure?

My plan is to wire the wastegate open. Idle it for a while, then drive it around while monitoring EGTs until it’s fully cured.

 

[chillman88]

Definitely interested to hear how it works for you. I have a slip joint on the turbo I'm going to be installing eventually and I've been thinking about what to put on it at assembly. I'm not fond of going back in later to fix things I should have done the first time.

 

[IDIBRONCO]

Personally, I like the copper gasket idea. If we could get some made, I'll bet they would sell out fast.