More exhaust leaks

I recently replaced my muffler with the OEM Toyota part that includes the mid pipe, muffler, and tailpipe in one piece. The flange at the mid pipe was a mess and I replaced the rusted off nuts with new locking nuts and washers. That went fine.

But I looked upstream and there are 3 other rusty flanges with donut gaskets... and the one in y-pipe just up from the mid pipe on the passenger side just started leaking. I was afraid that the other work would disturb these fragile things and it did.

I am going to replace that gasket assuming the flanges are solid enough and hope the 2 donuts at the connections from the manifold to the y-pipe and cats don't start leaking. If those start leaking we are looking at major work... it'll pretty much need all the pipes and cats up to the manifold replaced which is $$ enough... but those studs on the manifold flanges to the y-pipe are going to be a bear... or impossible to deal with without removing the manifolds... and those studs that hold the manifolds to the heads are also going to be a bear, or impossible to deal with without pulling the heads... etc. Damn rust.

Trading for a 3rd gen is looking better and better... which is too bad because I love my truck and it is running great.

 

In my mind.....that falls into the category of "Don't F with It".

Take it to an exhaust shop. Quote first. Then decide the repair/replace path.

 

Yeah, I might just do that. Maybe even the dealer if they will give me a firm quote. I just don't want to get into a situation where this is open end and some lummox breaks a stud and they want to charge me for cylinder head R&R. Not sure I would trust a typical muffler shop.

Again, I could do all this if necessary, but not ideal this being my DD and I don't want to leave my nice car outside of my one car "car closet" whilst I work on the Tacoma. And the tiny garage adds a major difficulty factor for this sort of stuff.

What year is the Honda in your avatar?

 

That is a very old bike. '81 Honda CX500C.

It was the first bike model to have liquid cooled, shaft drive. It also had high output for displacement. The holy grail for NA carb bikes was to get 100 hp from 1000 cc. This bike is 50 hp from 500 cc. Downside, its heavy....pushing 500 lbs. Not a crotch rocket by any stretch, but it is a nice nimble cruiser. Great around town. Strained at 75 mph. It was built and geared for 55 mph speed limits.

You listed other very valid reasons to use a shop for the work. I have a small single garage. Wife's CRV sleeps there. The truck is a tight squeeze for length. I have to work in there because the floor is level, the driveway has too much slope.

 

I remember that Honda. I believe they made that type of engine for a good long while. I had a 1983 V45 Sabre... and before that a 1977 550-four... both long since sold. We have a CT70 minibike up at the farm that I need to restore. That looks like fun.

Yup, the little garage thing is tough. I changed the cam in my old 1994 Z28 Camaro in there. Oof. I recently replaced the Tacoma muffler in there and that was really difficult, too, with the unit being all one piece. It sure was tricky to get in place. Right before that I replaced some of the Tacoma trans cooling lines (also rusted out) and flushed the auto trans in there. All made tougher by being in a cramped space.

I currently have a Triumph Tiger 800 and a Vette. I just can't leave those outside for the time it would take me to do this job, especially if I encountered stuck or broken studs.

 

That is a very easy fix for an exhaust shop. Two straight cuts. Two flange halves, gasket, two bolts. MIG it up and done.

 

Actually this fix is easy even for me. The flanges are OK. Just need to cut the bolts and put on new gasket, bolts and nuts. The problem is that if and when the *upstream* flange gaskets on the manifolds start leaking. They are a mess and extracting those studs or god forbid drilling one or more out is NOT an easy fix. Nor is removing the manifolds since THOSE studs are also a rusty mess. I already fixed the mid pipe, now I'll fix this flange... and I suspect I will have to chase this all the way up before it is over.

 

Turns out that this is indeed the final answer. Upon closer inspection the flanges were NOT OK. I had the new gasket and bolts ready to install and when I put a bright light on it it was obvious that the flanges were done and would not seal the gasket. One shop offered to cut the flange out and weld in a piece of pipe for cheap but they were very disorganized and lost my business. Then I found a better local exhaust shop and they will do it the right way with flanges... for a little more $$ but worth it. The tech looked at my manifold flanges and said they were still in good shape which makes me feel a lot better. He is going to drop the pipes from the manifolds in the process so I will get new donuts there, too. Since I just replaced the muffler a month or 2 ago the exhaust should be good to go for a long time.

 

I have had to drill out some OEM header to y-pipe studs before. It was an annoying process.. Some good quality, coated bolts or stainless bolts, will prevent future rust issues.

 

Very good.

 

The tech said all he uses is stainless steel hardware. That'll help for sure. I used stainless on the muffler assembly flange.

 

Looks like we are all on the same wavelength then.

Probably their solution to the problem of the salted roads. I bet most exhaust shops down here wouldn't use stainless.

 

Yup... I just wish Mr. Toyota was.

 

He and America's division have butted heads a few times.

 

Here is what it looked like after I knocked a few rust flakes away.


https://www.youtube.com/embed/_dXyH0DhgHw

 

Looks like the gasket was holding the exhaust together. Lol