• Mustang Forums
  • 1996 - 2004 SN95 Mustang -General/Talk-
  • SN95 4.6L Mustang Tech

Passenger side H-pipe to manifold gasket leak

  • Thread starter Thread starter Carl
  • Start date Start date Sep 7, 2004

Carl

Founding Member
Aug 7, 2000
613
0
0
Johnson City, TN
Sep 7, 2004
#1
  • Sep 7, 2004
  • #1
I am using the factory gasket not the crappy paper mac one, but I am still getting a small leak. the flange on the mac pipe doesn't have that lip on it like the factory one to hold the gasket centered. I am pretty sure it's not centering on the flange and squeezing out from one of the sides. Any one have any tips on this. I have had it apart and messed with it several times now. I tried it with the MAC gasket coated with some ultra-copper gasket maker, but it was worse than using a factory gasket by itself. If I put a little ultra-copper gasket maker on there with the factory gasket, will it work or will the gasket maker stuff just burn up eventually? I am going today to pick up some more factory style gaskets and give it another try. I think my main problem is that the hole in the mac flange is bigger than the stock one and the crush ring on the gasket isn't sitting on the flange, but rather falling inside the exhaust tubing. If the crush ring was just a little larger, so it would be farther out on the flange, it would work better. Is there any aftermarket gaskets that anyone has used that work good?
 

Snarf

New Member
Dec 24, 2003
237
1
0
Lexington, KY
Sep 7, 2004
#2
  • Sep 7, 2004
  • #2
Bro I had the exact same problem with my MAC O/R H pipe, and I could never get it to seal right. Three gaskets and two weeks later I said F*&^ that piece of junk, and bought a shiny, new stainless Bassani O/R X. It went on PERFECT first try, zero leaks, EXCELLENT quality! Just sell that POS MAC pipe like I did and get a good quality unit. You'll prolly dick around with that MAC unit for another month before you get it to seal finally.
 

Carl

Founding Member
Aug 7, 2000
613
0
0
Johnson City, TN
Sep 7, 2004
#3
  • Sep 7, 2004
  • #3
I'd like a nice SS bassani X-pipe, but right now money is an issue. I know it's a pain, but is it possible to get it to seal perfectly?
 

bham_gt

New Member
Sep 21, 2004
94
0
0
Birmingham, AL
Nov 10, 2005
#4
  • Nov 10, 2005
  • #4
Carl said:
I am using the factory gasket not the crappy paper mac one, but I am still getting a small leak. the flange on the mac pipe doesn't have that lip on it like the factory one to hold the gasket centered. I am pretty sure it's not centering on the flange and squeezing out from one of the sides. Any one have any tips on this.
Click to expand...
I am having the exact same problem! I think the lip on the stock gasket is not getting centered on the H pipe and is causing it to leak. Did you ever get this problem resolved? It's driving me crazy!
 
5

5.O STANG

New Member
Oct 15, 2005
44
0
0
Nov 10, 2005
#5
  • Nov 10, 2005
  • #5
I had that problem as well. I fixed it by using high temp silcon and sticking it back on. NO leaks now.
 

timeless2

Vi Veri Veni Versum Vicus Vici
Admin Dude
Nov 29, 1999
1,366
202
154
the Shadow Gallery
Nov 10, 2005
#6
  • Nov 10, 2005
  • #6
Did you get one of the older MAC pipes? Mine was the newer 3 piece design and had a very nice, thick gasket that I used. No leaks, no problems, 4 months later.
 

bham_gt

New Member
Sep 21, 2004
94
0
0
Birmingham, AL
Nov 10, 2005
#7
  • Nov 10, 2005
  • #7
4u2nv said:
Did you get one of the older MAC pipes? Mine was the newer 3 piece design and had a very nice, thick gasket that I used. No leaks, no problems, 4 months later.
Click to expand...
Hmmm...mine is the newer three piece design and the MAC gasket that came with it is pretty thick (maybe 1/8"). I thought about trying to use it, but seems like everybody thinks the mac gasket is crap. Although I do remember reading something about there being an old MAC gasket and a new MAC gasket. Is the new one better??
 

timeless2

Vi Veri Veni Versum Vicus Vici
Admin Dude
Nov 29, 1999
1,366
202
154
the Shadow Gallery
Nov 10, 2005
#8
  • Nov 10, 2005
  • #8
bham_gt said:
Hmmm...mine is the newer three piece design and the MAC gasket that came with it is pretty thick (maybe 1/8"). I thought about trying to use it, but seems like everybody thinks the mac gasket is crap. Although I do remember reading something about there being an old MAC gasket and a new MAC gasket. Is the new one better??
Click to expand...

I think the new (thicker one) is better. The one you hear people b1tch about most is the older design. The newer one shares moulds like the prochamber, so it's a much better design all-around.
 

sgarlic

Founding Member
Apr 21, 2001
3,085
1
56
Nov 10, 2005
#9
  • Nov 10, 2005
  • #9
That thick one they include IS the one people refer to as crap. Because it's made of that foamy material and burns up and flakes off after a while supposedly. The Ford one is metal or something. I bought a new Ford gasket but did my midpipe swap with like 5k miles, so I didn't need it. Never had a fitament problem, no leaks, etc.
 

timeless2

Vi Veri Veni Versum Vicus Vici
Admin Dude
Nov 29, 1999
1,366
202
154
the Shadow Gallery
Nov 10, 2005
#10
  • Nov 10, 2005
  • #10
sgarlic said:
That thick one they include IS the one people refer to as crap. Because it's made of that foamy material and burns up and flakes off after a while supposedly. The Ford one is metal or something. I bought a new Ford gasket but did my midpipe swap with like 5k miles, so I didn't need it. Never had a fitament problem, no leaks, etc.
Click to expand...

Mine was not foamy and it actually covered the opening quite well.
I guess I'll find out if problems arise.
 

bham_gt

New Member
Sep 21, 2004
94
0
0
Birmingham, AL
Nov 10, 2005
#11
  • Nov 10, 2005
  • #11
Yeah, the one I have is not foamy. I might try it and see if it works any better than the stock one.
 

sgarlic

Founding Member
Apr 21, 2001
3,085
1
56
Nov 10, 2005
#12
  • Nov 10, 2005
  • #12
Wow.. I also had the 3 piece kit and it came with that foamy piece of crap.. ah well.
 

timeless2

Vi Veri Veni Versum Vicus Vici
Admin Dude
Nov 29, 1999
1,366
202
154
the Shadow Gallery
Nov 10, 2005
#13
  • Nov 10, 2005
  • #13
sgarlic said:
Wow.. I also had the 3 piece kit and it came with that foamy piece of crap.. ah well.
Click to expand...

Where and when did you purchase it?
I got mine in July 2005, from brenspeed.
 

sgarlic

Founding Member
Apr 21, 2001
3,085
1
56
Nov 10, 2005
#14
  • Nov 10, 2005
  • #14
February 15th 05 from brenspeed. It's the coated version (the black one) of the Mac o/r H.
 

timeless2

Vi Veri Veni Versum Vicus Vici
Admin Dude
Nov 29, 1999
1,366
202
154
the Shadow Gallery
Nov 10, 2005
#15
  • Nov 10, 2005
  • #15
sgarlic said:
February 15th 05 from brenspeed. It's the coated version (the black one) of the Mac o/r H.
Click to expand...

I got the non-coated one. I'm at a loss.
 

bham_gt

New Member
Sep 21, 2004
94
0
0
Birmingham, AL
Nov 10, 2005
#16
  • Nov 10, 2005
  • #16
I got the non-coated one in September '05. I guess there's only 1 way to find out if it works or not...too bad it will probably be a while before I can do it. Just too busy lately.
 
You must log in or register to reply here.

Similar threads

R
bbk shorty header to mid pipe gasket
  • randyyy
  • Sep 29, 2025
  • 1996 - 2004 SN95 Mustang -General/Talk-
Replies
4
Views
357
1996 - 2004 SN95 Mustang -General/Talk- Sep 29, 2025
randyyy
R
P
Engine Mysterious coolant leak at back of engine
  • palerider94
  • Jan 18, 2026
  • Fox 5.0 Mustang Tech
Replies
1
Views
189
Fox 5.0 Mustang Tech Jan 19, 2026
AeroCoupe
B
water pump installation questions
  • B0udreaux
  • Feb 5, 2026
  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
  • 2
Replies
38
Views
2K
1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk- Feb 28, 2026
General karthief
J
Exhaust manifold to Y-pipe nut & stud dimensions?
  • joeybuddy96
  • Jul 7, 2026
  • SN95 V6 Mustang Tech
Replies
2
Views
76
SN95 V6 Mustang Tech Jul 9, 2026
joeybuddy96
J
O
8.8 Pinion Nut Leak
  • OX1
  • Jan 3, 2026
  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
Replies
15
Views
810
1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk- Jan 5, 2026
OX1
O
Share:
Bluesky Email Share Link
  • Mustang Forums
  • 1996 - 2004 SN95 Mustang -General/Talk-
  • SN95 4.6L Mustang Tech
Menu
Log in

Register

  • Forums
  • What's new
  • Media
  • Resources
  • Contact
  • Sponsor
X

Privacy & Transparency

We use cookies and similar technologies for the following purposes:

  • Personalized ads and content
  • Content measurement and audience insights

Do you accept cookies and these technologies?

X

Privacy & Transparency

We use cookies and similar technologies for the following purposes:

  • Personalized ads and content
  • Content measurement and audience insights

Do you accept cookies and these technologies?