exhaust leak between headers & y-pipe (1 Viewer)

[Layonnn]

I am in the process of replacing my exhaust system.

Today, i installed the y-pipe onto the header with new crush gaskets. The pipe has the two cats on it and one O2 sensors. I connected everything together and fired it up to check for leaks. (all used OEM stuff, except new O2 and gaskets. headers were not replaced.)

I am getting leaks right where the y-pipe meets the headers.

What could be causing this since they are new crush gaskets? The gaskets sit around a little lip of pipe, so it's not like they are not centered. Any ideas for a fix?

Thanks.

 

[Atoyot1031]

I assume you mean the manifold not header. If your leak is in fact right where the two meet than the crush gaskets somehow were not installed correctly or did not crush correctly. I had this happen on my old minitruck.

To check where your leak is coming from start with a cold engine/engine bay. Fire it up and feel around for the air flow.

Also, those studs can get pretty corroded with age and heat. You could have torqued them down properly, but due to corrosion they did not properly crush the crush gaskets.

Leaks on the inside seam of the "Y" in the y-pipe are also very common.

Good luck!

 

[Layonnn]

I assume you mean the manifold not header. If your leak is in fact right where the two meet than the crush gaskets somehow were not installed correctly or did not crush correctly. I had this happen on my old minitruck.

To check where your leak is coming from start with a cold engine/engine bay. Fire it up and feel around for the air flow.

Also, those studs can get pretty corroded with age and heat. You could have torqued them down properly, but due to corrosion they did not properly crush the crush gaskets.

Leaks on the inside seam of the "Y" in the y-pipe are also very common.

Good luck!

I thought the difference between headers and manifolds were headers came off in individual tubes and then collected where as manifolds all go into the same pipe nearly as soon as they come off the engine block. Oh well, you know what i mean

The studs are good. I checked them and ran over them with a die to make sure the threads were clean. I also cleaned up the area around the gasket with a wire wheel brush to remove any debris or possible rust.

I ran my hand around and can feel the exhaust leaks. Its only in one spot on both pipes.

I will remove it tomorrow and check the crush gaskets.

 

[NKP Garage]

check the flange surfaces of the manifolds to make sure they're flat and not heavily pitted. if they are try smoothing them out. Worst case if you still can't get a good seal smear a little copper high temp RTV on either side of the gaskets and reinstall and that should take care of any pinhole leaks: http://images.solidcactus.com/autobarn/per81878.jpg

 

[Layonnn]

check the flange surfaces of the manifolds to make sure they're flat and not heavily pitted. if they are try smoothing them out. Worst case if you still can't get a good seal smear a little copper high temp RTV on either side of the gaskets and reinstall and that should take care of any pinhole leaks: http://images.solidcactus.com/autobarn/per81878.jpg

That is what i was planning on tomorrow. I didn't have any room to get the wire wheel brush up under the manifold. But i will try the dremel and wire brush tomorrow.

 

[Layonnn]

That is what i was planning on tomorrow. I didn't have any room to get the wire wheel brush up under the manifold. But i will try the dremel and wire brush tomorrow.

Did this, still had the leak.

I got some of the copper high temp sealant. Put a thin bead on each side of the gasket. Will let it cure 24 hours and start it up tomorrow and check again.

 

[sicilian]

Retarded PO

I am sure you already got this fixed, but I just wanted to relay what was causing this on my 97. Same issue leaking at the crush gaskets, dropped the y-pipe and after realizing that the threads were chewed on the studs decided to replace those, (one came out with the nut, the others are frozen in there). Went down to the dealer and got the correct studs, and lo and behold they were different, much less unthreaded area, someone before me had replaced them with factory manifold to head studs thinking exhaust studs are all the same. What this means is that when you tighten down the nuts they never tighten all the way just jam into the end of the threads, also buggering the threads when they have to be removed. Thanks PO! Still have to remove the frozen studs as soon as it stops raining. Any hints on removing these manifold to y-pipe studs? I have already tried heat but did not get it red hot, and it has been soaking with PB for days. Not looking forward to drilling them out, or removing the manifold.

 

[Otamiway]

I ran into the same issue. Heat and vise grip worked for me. Make sure to get most of the heat on the manifold

 

[sicilian]

Thanks, but unfortunately I ended up eventually having to both remove the manifold and drill the stud out. One came out with heat and a stud socket, but the other just broke off, leaving about 3/8 sticking out, so I removed the manifold (actually came off no problem, I would have done this right off if I knew I wasn't going to have any issues there) and clamped the stub in a vise and turned the manifold, and the it broke off flush. This stud was so fused I had to drill it out all the way to the thread minor diameter and pick and peel thread bits out enough to get a tap to start in the same thread. It is out now and cleaned up pretty well, probably have about 85 percent thread, but it should hold no problem the new stud doesn't feel too loose. So tomorrow it goes back together, definitely the most frozen stud/bolt I have ever had to deal with.

 

[Beej]

What size stud socket is used here?

Also, can any (correct size) nut be used or is there something unique about these?

 

[NKP Garage]

What size stud socket is used here?

Also, can any (correct size) nut be used or is there something unique about these?

There are special split top locking nuts that are used on exhaust components. You can get them at the dealership or most auto parts stores.

 

[NKP Garage]

The OEM Toyota ones look like this. I would just hit up one of the vendors on here that sells OEM toyota parts to get the correct nuts and studs:
https://www.amazon.com/Genuine-Toyota-90080-17187-Exhaust-Pipe/dp/B000QSTZT8

 

[Beej]

Exhaust Manifold/Downpipe Gasket Part #

This thread is a good guide!