turbo to exhuast pipe cracked fumes in cab hot to repair?

[GMichaels]

Just got back from picking up my 93 350. A few disappointments on the way, and things I had missed.



but I need to fix this problem so I can drive the truck.



where the exhuast pipe conects to the turbo there is a crack in the pipe and now some exhuast leaks out.



It appears that the air for the cab is taken from the engine compartment, when I start the truck with the vent selected you can see a puff off smoke come through the vent. smell is not that bad if you go at high speed.



Now looks like someone put a hose clamp around the pipe and some copper silicone to seal it. I am not sure how the connection should be, is there a gasket? what is the best way to fix this without spending a lot of money, SS is expensive, should I get it welded?



Greg

 

[Paychk]

Greg welcome to the forum



I'm not sure what you are asking, more info will help, does your truck have an exhaust brake or just a stock system? (at least where the pipe hooks to the turbo).



If you go the the user control panel (white button located at the top of the page) and select the profile tab and fill out the signature line with details about your truck, it will help when others respond to your Q's.

 

[dusthomps]

If it were me, I'd just weld the crack in the pipe and reinstall. There is no gasket between the down pipe and exhaust housing, just the band clamp.





Dustin

 

[Paychk]

Originally posted by dusthomps

There is no gasket between the down pipe and exhaust housing, just the band clamp.





Dustin

If there is a brake installed on the turbo and it is from pac-brake there is a v-band clamp (between turbo and brake) and a ball & socket connection at the pipe itself.



Need more info!

 

[GMichaels]

ok add tag line. This is a 93 350 diesel no mods, although I don't know how to tell what turbo I do have.



I should have check closer, the pipe is not cracked. But if there is no gasket, don't understand how this joint is sealed? I have not pulled the joint apart yet, but it is covered up with copper silicone.



Does the pipe slide over the turbo housing? and that clamp is suppose to seal the pipe against the cast turbo? Now I see how this can be a probem, I may have to make my own gasket.

 

[Paychk]

The stock pipe is a butt connection to the turbo. The connection is held tight by a V band clamp, this clamp may have stretched to the point it won't seal. Also the pipe flange may not be square to the turbo outlet, you may need to loosen the exhaust and reset the flange to the turbo. There is no gasket between the two and putting one there is a band-aid like the silicone from the previous owner.

 

[Paychk]

This is the inside of a V band clamp. This should be the type of clamp on your exhaust at the turbo.

 

[GMichaels]

yep thats he clamp, i will have to scrape all he goop off and see why its leak so bad, maybe its a cracked turbo housing.



How do you post a picture?

 

[Paychk]

When you are on the "post reply" page under the text box is an "attach File" box. Browse to the location on your computer, select the file and away you go. File size is limited to 32 Kilobytes.

 

[Philip]

Sounds like you have a cracked flange on the down pipe. I have had to replace two down pipes so far in 6 years from this flange cracking or breaking.



Check the pipe mount at the bottom of the bellhousing. Both times mine cracked this mount had came loose. This lets the pipe vibrate and causes the cracks to happen.



If you find the mount bolt broken off in the bellhousing post back I can tell you how to repair it.

 

[dpuckett]

If you can stand the smell of diesel exhaust, it is drivable to get you home. Unlike a gasser, you dont have to worry about CO poisoning from the fumes. Just a sulphery smell once in a while. Sounds like the exhaust pipe got cocked askew and is not sealing like it should. Get a new clamp, loosen the downpipe from the transmission bellhousing so it will move. Line up the DP to the turbo outlet and tighten the clamp around it, then tighten the clamp down at the bell housing. THis should seal the pipe to the turbo. I have done it a time or two when I shortened the pipe to install a wastegated housing and didnt get the cut exactly 90 deg. There is some room for error.



Daniel

 

[GMichaels]

Ok I took the clamp off and found that the ring on the end of the down pipe was rewelded and not centered around the pipe.



Now I don't know what a good one looks like. Mine has the main pipe and at the end that connects to the turbo there is a smaller pipe in the main pipe and welded. then at the end of this smaller pipe is the ring that butts up against the turbo. Does that sound normal or as this been cobbed up??



I know this coupling does not need a gasket, but is the a gasket material I could use around this clamp, else I have to remove the down pipe and cut off the ring and reweld. I assume this is SS so I won't be able to do it.



I removed a lot of copper silicone around this joint, there must be something better...

 

[Philip]

Copper silicone is about the best for this app. A place I used to work at we used it on all band clamps on semi tractor exhaust systems.



The neck down setup you talked about is normal for our stock down pipes.



Rewelded sounds like it has broken once before. It needs to be straight to the turbo. Its time to cut and reweld or replace the down pipe.