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Intake Manifold Leak
Hey everyone, long time no post. Just trying to graduate this place lol.

On to the issue. Duchess has developed an intake manifold leak. I ordered a new gasket. I am now at the point where I would like to know what I should do and not do to make this a nice clean repair.

I'm under the impression that the front and back of the manifold tends to develop leaks when the stock rubber gasket squishes out. So a bead of black RTV is in order on the front and the back. Is there a better tightening order or different torque settings I should be using for this.

The job seems run of the mill to me. Follow the Chilton's manual, don't lose any parts. I would like to hear any wisdom or advice though. Thanks.
sounds like your on the right track. Remeber to follow the torque sequence. i beleive it starts with the inner bolts first and works its way out. been a while since i have done this job, but i think you torque them twice also. 1st time at lower setting then at the reconmended setting. someone else will let you know and it should be in the book. Use a nice bead of silicone at each end and dont put the gaskets on backwards. they should be stamped which way to go.


1971 Mach 1
408C Stroker
C4 w/3,000 stall
8.8" Rear w/3.73's
Disc brakes all way around.

[Image: 28ivsix.png]

I take a very sharp punch and hammer and tap along the front and rear surface of the block, where the rubber sits, just hard enough to rough it up.
It stops the rubber from sliding.
Kevin's got it right, torque at 1/2 the final torque working from the middle out to the ends. Repeat at full torque then I like one final time at full torque. If you use a gasket with sealing beads incorporated just put a dab of sealant in the joint where the block meets the heads. Do not put sealant on the gasket or end rail surfaces, install them dry.

Jeff T.

Low buck, touring style, '73 Convertible "rolling restoration", 351c, 2v heads with a shave and a haircut, Performer intake, Holley 650(ish), roller rockers, screw in studs, guideplates, stainless valves, Duraspark / Motorsports MSD, T-5 conversion. 1-1/8" front, 3/4" rear swaybars KYB shocks and some home brewed subframe connectors. Future plans; JGC steering box, Cobra brakes and... paint, interior, etc.

When I die I want to die like grandpa, peacefully in my sleep... not screaming, like his passenger.

[Image: 1_12_09_14_10_15_11.png]
I always use a thin layer of good silicone to glue the gaskets in place. Let them set up completely then they cant slip and slide around as your setting the manifold down on them. Also get some extra long spare bolts cut the heads off them and put them in the 4 corners of the heads then you have a nice "guide" to lower the manifold down over. Then you can just take the studs out and swap them for your bolts. Ive never had a leak doing it this way. If you dont use studs be very careful to come straight down as not to disturb the gaskets. I hear a lot of guys say ditch the gaskets and just use the silicone... Ive never had a gasket slip out because I glue them in and let them set up completely before my intakes go on. Good luck!

one more thing I take my shop vac and duct tape some 3/8 inch tubing to the end of it and you can use it to suck coolant out of all the small places it ends up when you pull the manifold off. And change your oil afterward! if your oil is fresh and you dont want to waste it drain it into a clean container then buy one or two quarts of cheap oil and pour it down the lifter vally with the oil pan drain plug still out to flush any coolant or gasket material that may have fallen down there.

72 Mach-1 12:1 532 Forged internal Scat stroker, Kaase P51 heads, Comp roller cam, March serpentine conversion, C6 manual VB, 9'' 4:33:1.
66 convertible 289, 82k miles.
First time i put mine on..It leaked ...I didnt put enough silicone on it..Second time i just used the cheap cork gaskets up front and back..they had stick side allready...did not slip a bit...lol..sealed right up
And don't break the bolts!!!


[Image: 25yvyp3.jpg]
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