View Full Version : exhaust leak

bing kunzig
10-27-2005, 08:32 PM
I developed a leak in my silver hawk at the flange. Took it to the shop where the gasket was replaced by a donut type thing. Ten days later the leak is back! Any ideas on why this would reoccur?

I developed an exhaust leak in my silver hawk at the flange. Took it to the shop where they replaced the gasket with a donut type thing. Ten days later the leak is back! Any ideas why this would re-occur?

10-27-2005, 11:00 PM
Well, I can envision a "Donut" style gasket working to a degree, but it's not what is supposed to be there. Besides, the way I envision it, that donut would effectively reduce the diameter of the outlet.:( Not something that would help performance.[}:)]

Miscreant at large.

1957 Transtar 1/2ton
1960 Larkvertible V8
1958 Provincial wagon
1953 Commander coupe
1957 President 2-dr
1955 President State
1951 Champion Biz cpe
1963 Daytona project FS

03-31-2006, 05:01 PM
Does anyone have a modern part# for the flange gasket at the manifold for the later 289 V8. I was looking to gat something at my FLAPS.

Dave in IN
1964 GT Hawk

03-31-2006, 06:44 PM
ask for one for a '67 Caddy.

I had to replace a manifold on my car because that mating surface was so far out of true that the gasket wouldn't work. If you can pull the studs without breaking them you might want to have this surfaced, or just buy a NOS manifold from SASCO.


55 Commander Starlight
62 Daytona hardtop

Blue 15G
03-31-2006, 07:37 PM
Sometimes using more than one gasket on the flange solves the problem.

I agree too, that the car should use a flat gasket, not the donut type.

chocolate turkey
04-01-2006, 10:09 AM
Also, for a minor warpage issue, a little high heat silicone on both sides of the gasket will help. There is no issue with sensors being damaged, so don't be afraid of a little "glue". Used it for many, many years while working in the trade.


Brian K. Curtis

04-01-2006, 11:22 AM
Check the nuts on the exhaust flange. Brass nuts are used so that they don't corrode and get impossible to remove. They work so well that the engine vibration can loosen them easily as the pipe moves sideways against the manifold. Be sure you have two nuts on each stud and lock the outer one against the other to keep them from unwinding. Vibration will always loosen a nut, never tighten it!

Gary Ash
Dartmouth, MA
'48 M5
'65 Wagonaire Commander
'63 Wagonaire Standard

04-01-2006, 12:05 PM
Thanks for the replies.

Dave in IN
1964 GT Hawk