V Band Exhaust leak

[98RedGTS]

I'm just about at my wits end with this dang V-Band connection on the drivers side collector. I finally got all my leaks taken care of with the exception of this single one. If it was minor I'd just leave it at this point but it's still leaking really bad. You can hear it clearly in the car and I can even feel it if I put my hand about a foot away from the connection.

Is there something that can be used to help seal up these connections?

This past weekend I took everything back off the car and started over. Still same results. As part of this connection I used a wire brush and cleaned off both sides of the connection and removed all surface rust. I'm reusing the old V-band clamp since I can't find new ones. I'm lining it up as perfect as I can and snugging down the clamp after making sure it's lined up with where the rest of the exhaust will go.

I'm just not sure what else I can do.

If it helps, it's a Belanger HF cat kit.

[pokeyl]

I had my best luck with the cat not connected to the muffler at all
Ask another person pushing the 90 deg cat section toward the exhaust manifold as you start the clamp.
After you start the clamp it should rotate freely, and the 90 deg cat should also pivot freely before you tighten it.

Do you have true V-band connection? Many exhaust system maker have started just flaring the pipe. Its very hard to get then to seat with a V-band!!!

[98RedGTS]

It's the factory band on the header. The cat side is the Belanger kit. It look exactly like the factory one.

[pokeyl]

Copy, that's the easy one to seat, one is a male the other female. In aerospace we use thin crush gasket between the two. Zero leaks. Google "3 inch V-band clamp seal", McMaster Carr may have them. Hope this helps.

It's the factory band on the header. The cat side is the Belanger kit. It look exactly like the factory one.

[Racngrn]

I actually just installed the Belanger cats and Corsa 3 inch on my 98 GTS. I ordered new V Band clamps ( Parts Rack) that came from Belanger but was able to use the original V Bands and have no leaks. In the past I have used an exhaust sealant ( like an orange colored paste) for stubborn head pipe leaks on my 60s Muscle cars. Works well if used correctly. Maybe an option though pretty nasty looking. Did you verify that the "V" portion of the clamp wasn't deformed after removing the first time? Mine got a bit bent but I was able to straighten it out rather well with some time and care. AS an aside, the clamps sent by Belanger looked very sturdy. Another option maybe. Steve

[dave6666]

Lubricate all the friction and mating surfaces of the exhaust itself and then the clamp to the exhaust with hi-heat nickel based antisieze. It will reduce the friction of those surfaces while allowing them to pull tighter without increasing the torque at the clamp. Also apply some to the threads of the clamp where the nut or screw is. The antisieze will smoke for a few minutes but will burn off quickly.

[98RedGTS]

Appreciate the advice. I'll give the antisieze a try first then will go the gasket option.

Racngrn - The clamps I got from Belanger were just band clamps. Those all sealed and worked great. Just the V-band causing me issues. As far as I can tell the clamp itself is good. I did take quite a bit of force to get it to break lose when taking it off the first time but I couldn't see anything that looked bad outside of the fact that the little pivot points for the bolt don't move very easily.

[98RedGTS]

Let me ask a potentially dumb question. I know Lou stated the flex tube isn't needed with his kits but would it be worth while to have a small flex tube spliced in where the factory ones are normally located in relation to helping with install and sealing of the exhaust at the collectors? I'm wondering if that flexing from the drivetrain is possible part of the problem. I have polly engine and trans mounts so it's pretty minimal but trying to think of all options.

[JonB ~ PartsRack]

The flex is a turbulent restriction and a heat-soak, and is NOT needed if you dont anchor the elbow.

[pokeyl]

The flex is a turbulent restriction and a heat-soak, and is NOT needed if you dont anchor the elbow.

So leave the front side pipe mount off? and the I can use the solid elbow pipe?

[98RedGTS]

Yes, that's how the kit is designed.

[Camfab]

If it were me, I'd diagnose exactly whats causing the issue. I'm guessing that something downstream of that v-band connection is causing a misalignment issue. When you remove the v-band at that junction, are the flanges perfectly parallel to each other, there should be zero misalignment. If you start at the header and work your way out, you'll likely see misalignment with the rest of your exhaust. Your poly engine mounts, as well as a number of other issues can cause misalignment. I've done multiple installations with v-bands and while they are the absolute best method of exhaust connection, they require absolute precision. In each of my installations I've always had to cut the elbow and re align the tube into the side sill for perfect alignment. Not anchoring the tube in the side sill due to misalignment, or as a band aid is a really bad idea. You want to keep the exhaust stabilized within the side sill, not rubbing pipes within the confines of the body. The factory put those flex points in exactly for this reason. Another potential issue that I've seen is that the factory headers crack at the weld where they come together at the collector, though it sounds like that is not your issue.

[SlateEd]

many years ago I did RandomTech hi flo cats on my Gen3, and thought I had them clamped correctly. Went for a drive and after hammering through 1-2-3 on a highway entrance the driver's side cracked loose... sounds like about as much of a leak as you're describing.

I realized that the RandomTech pipe was just a shade smaller than the male flange of the factory manifold. It felt "okay" when I had it clamped but apparently it wasn't seating all the way into the V. I took a cast iron horn of some sort (don't even remember where I picked it up honestly, but search exhaust expander) and expanded the end of the new pipe by just over 1/16" put it all back together and perfect fit. no problems ever since.

[Racngrn]

The clamps included with my high flow cats from Belanger are V Band clamps. Ordered them separately . Jon B will know numbers. They appear to be very close to originals and nice quality. The band clamps were also included to mate to the Corsa. I can dig out PN if you need it. Thanks

[98RedGTS]

Would love the part number on the V band clamps. If I can get some new ones I'd love to throw them on just to see if that helps. It's entirely possible I damaged it when removing them as I had to apply a large amount of force to get them to break loose from the stock pipes.

[Racngrn]

I looked at the invoices and only see "V Band Clamps " on my invoice from Jon B. They arrived from Belanger packed with the Cats and band clamps. Hope that helps. I'm sure Jon B can get you hooked up.