The pipes slip into one another. However, there is about an 1/8" gap around the pipe. I do not have a picture of a Kooks Y-Pipe but it narrows down from 3" at the end where it connects to the I-Pipe.

 

Do you have an 18 wheeler type repair shop local? Like a Freightliner dealer? If so they sell a clamp just like the one you have but it is made with a "step" for pipes that slip inside each other. The clamp is not flat. That will fix the problem.


David

 

The problem is not the step, it is the design of the clamp. Air escapes where the bolts tighten the clamp together. It is a poor design but I think this is how all band clamps are designed.

If the coke can idea does not work, I will bring it back to the shop that should have welded the pipes together as I asked.

 

Hey guys, keep in mind that these clamps need to be tightened with an impact wrench, not by hand. When I put mine on, it had what you were describing (small "blow by leaks" near the clamp body). I crank on 'em as much as I could with my hand wenches. Still leaked. So I broke out the impact wrench and hit it hard. It actually deformed the clamp to take on the shape of both pipes (one's a little smaller then the other), and it hasn't leaked at ALL since then. This is on a 12.5:1 383 through a full exhaust, so you know it's got some back pressure. I really thought I'd break the bolts off when I was tightening it though.

Dave C.

 

How big is the step on these? I am needing a 2.5 to 3in step. If nothing else i will RTV the neck out of the pipes

 

what you need to do is roll up some aluminum foil and put it in the clamp where the 2 ends come together, then tighten the clamp down. Use the foil to act as a gasket for the "gap" area with this style clamp. Also you really need to make these tight.

I assume that your leak is from that part of the clamp. If its leaking from another part of the clamp then get a new clamp and you need to clean off the pipes with some scotch brite to make them smooth. Rusty pipes equal leaky pipes.

Use some aluminum foil to fill the gap instead of gasket material.

 

Right now i am using reg. muffler clamps(which suck) but i had intended to use some band clamps. However the step made that impossible. I will definately use the aluminum foil idea and probably some rtv aswell to ensure i get it sealed.

 

Band clamps are made to conform to the shape of the pipe. So a 3" pipe that was expanded and now over top of a 3" pipe will seal up just fine with a band clamp and some foil. You need to really make them tight however. Tight so that the metal of the clamp stretches around the and conforms to the pipe. A little foil in the joint and your golden. Wont leak, rust, or fall out. Dont bother with the RTV... it wont hold up in the long run anyway. The RTV will eventually burn off and deteriorate with the weather and road salt and leave an empty space behind to leak.

If the pipes being joined were made propery then the slip fit should be snug. If they are loosy goosy then the expanded side was expanded too much and should be replaced. But nobody will ever do that so just a little foil in the joint will help seal it up. Now I saw someone mention a 2.5" to 3" joint.... wont work with a band clamp. Need to make an adaptor and use 2 clamps.

The ultimate way is to weld all your joints.

BTW, I hate regular U clamps. They distort and bend the metal to join the 2 pieces and then you can never get them apart

 

My original intention was to weld it all together but with still having stock y and s-pipes i didnt want to do that. So now that i put a cutout in place of the cat i had to make adaptor pipes to mate up to those. Which is what gives me the problem with not being able to use band clamps. The pipes fit very snuggle into eachother, the clamps just are crap.