Hello, I just had to swap my old stock H-pipe in to go pass an emissions test. When I put my H-pipe back on, the one without the converters, I keep getting exhaust leaks around the ball of the headers where the H-pipe connects to them. When I tighten up the nuts on the flanges, it seems to not want to seal properly giving me annoying exhaust leaks. I have had the headers and H-pipe for prolly 6 years now. I have taken the H-pipe off probably 5-6 times with doing matenence on the car. Can someone give me some feedback of what I can do or should do to get the H-pipe to seal good against the headers where the flanges connect. It looks like when I tighten the flange up that its just not sealing flat. Please forward feedback to [email protected]. Thank you.
Exhaust leak at where headers and H-pipe connect
- Thread starter blk92mustang
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When you tighten up the flange make sure that you try to keep it pretty even. Don't tighten one side up and then tighten the other side up. You have to tighten one side a few turns and then the other side the same amount of turns. Otherwise you can end up with leaks cause it is kinda cocked and really tight on one side. At least that is my experience with them.
Skoobie
Damn...Tyler65's hot!
onefstsnake
New Member
I have the same problem.
Im ordering a set of donut gaskets from Summit.
Just search "donut" edelbrock makes 2.25" and 2.5" ones.
They will go between the headers and H pipe.
I hope it works out.
Im ordering a set of donut gaskets from Summit.
Just search "donut" edelbrock makes 2.25" and 2.5" ones.
They will go between the headers and H pipe.
I hope it works out.
Over-tightening the exhaust flange results in crushed ball sockets, and we can all agree it's a terrible, terrible thing when you crush your balls. 
I fought this issue quite a bit when hooking up my UPR cat'ed X-pipe, and I still have just a teeny-tiny bit of a leak at the flange - not enough to hear or to really affect anything, just enough that I know it's there if I have my hand right next to it.
Depending on how your exhaust is set up, check the clearance you've got all the way back to the flow tubes (the rear ball socket flanges after the H, before the muffs). If your H/X is hanging way low, it could be pulling the top end off center from the flanges at the headers, and thus it won't seal. With mine, some dimwit at UPR's welding shop decided to weld in the cats one inch too far back so that the rear of the cat hits the tranny crossmember before the X-pipe assembly can be fully lifted into position - I could never raise the thing high enough to get a proper seal. My half-arsed remedy for this was to grind a clearance notch in the crossmember, which gave it enough room to move it up to ALMOST fully seal at the flanges, but it's still too low and not exactly on-center.
If your X/H-pipe has those annoying hangers that poke into the mount on the transmission crossmember, do yourself a favor and hack those things off - it'll give you more adjustment for height, and allow you to swing the assembly far enough up or down to maybe give you the angle you need to seal it up. (Don't worry, your exhaust isn't going to fall off as a result of chopping the trans hangers. The UPR X-pipes and some other brands don't even have the hangers at all, and they hold up perfectly fine.)
Hope this helps. Oh, and while I'm thinking of it ... anyone wanna invest in a rust-free second-hand Dynomax cat-back and cat'ed UPR X-pipe with only six months on 'em?
I fought this issue quite a bit when hooking up my UPR cat'ed X-pipe, and I still have just a teeny-tiny bit of a leak at the flange - not enough to hear or to really affect anything, just enough that I know it's there if I have my hand right next to it.
Depending on how your exhaust is set up, check the clearance you've got all the way back to the flow tubes (the rear ball socket flanges after the H, before the muffs). If your H/X is hanging way low, it could be pulling the top end off center from the flanges at the headers, and thus it won't seal. With mine, some dimwit at UPR's welding shop decided to weld in the cats one inch too far back so that the rear of the cat hits the tranny crossmember before the X-pipe assembly can be fully lifted into position - I could never raise the thing high enough to get a proper seal. My half-arsed remedy for this was to grind a clearance notch in the crossmember, which gave it enough room to move it up to ALMOST fully seal at the flanges, but it's still too low and not exactly on-center.
If your X/H-pipe has those annoying hangers that poke into the mount on the transmission crossmember, do yourself a favor and hack those things off - it'll give you more adjustment for height, and allow you to swing the assembly far enough up or down to maybe give you the angle you need to seal it up. (Don't worry, your exhaust isn't going to fall off as a result of chopping the trans hangers. The UPR X-pipes and some other brands don't even have the hangers at all, and they hold up perfectly fine.)
Hope this helps. Oh, and while I'm thinking of it ... anyone wanna invest in a rust-free second-hand Dynomax cat-back and cat'ed UPR X-pipe with only six months on 'em?
onefstsnake
New Member
Im interested in the Catted UPR X pipe.
But Im still waiting for the bill for getting my rear end built...
But Im still waiting for the bill for getting my rear end built...
Nothing against UPR, per se, but I'd steer clear of their cat'ed X-pipe. The way they weld the cats in so far back is the reason why I've had such a headache trying to get the thing to fit correctly, thus the above mentioned leaks and such. Their off-road X-pipe should be fine, though, as it would fit perfectly fine without the cat placement issue - not having to deal with those stupid tranny crossmember hangers helps a lot, actually.
hey, are these the ones: http://www.jegs.com/webapp/wcs/stores/servlet/category_10001_10002_20729_-1_10259
1991vert
10 Year Member
onefstsnake
New Member
I ended up putting some hi temp RTV on the flanges and bolting it all up. Doesnt leak at all now.
onefstsnake
New Member
well I put the RTV on about 5 months ago, and have since put over 3k miles on the car.
So Id say it works good.
So Id say it works good.
onefstsnake
New Member
well I did talk to my local mustang shop about the gaskets and they said they are mainly for LS1's/LT1's
I had them put a bunch of high temp Orange RTV on the header flange and the Hpipe. Works fine.
I had them put a bunch of high temp Orange RTV on the header flange and the Hpipe. Works fine.
