Power Brake Booster to Firewall Seal

[George R]

Where the brake booster bolts to the firewall, there is an oddly shaped hole inside the 4 stud cricle. The booster brackets mount to these 4 studs. What actually seals the hole in the firewall where the brake pedal rod comes through? I have the gasket from DMT, and it matches the pattern of the studs and the hole, but there is nothing for it to seal against.
Am I missing a part somewhere? Service manual shows a "plate", but doesn't go into detail.
Any help appreciated.
69 Dart. 10" power drum brakes

George

 

[AdamR]

George, Can you post a picture of your firewall ?

 

[George R]

Here Adam.
Firewall
Brake Booster/Master Cylinder
Gaskets

George

 

[AdamR]

Mine is just a round hole in the firewall. I also have the same parts as you. No extra plate. I think the plate was a B-Body thing. I dont remember seeing them on any A bodies.

 

[George R]

Do you know what seals the boot to the firewall? Does the PB boot have a metal reinforcing plate with the 4 holes in it or something? If I assemble it they way it is, there will be a hole in the firewall to allow water in the car.

Any ideas at all will be appreciated!
Thanks dudes!

George

 

[71DartGuy]

My booster did have a plate that went on the booster side of the pushrod. It was very thin metal and had a rubber boot in the middle that sealed around the rectangular pushrod. The gasket goes between it and the firewall. I could probably snap a pic if you need to see it.

 

[Nilson767]

Ok so I'm having a gasket issue assembly but mines not the fire wall gasket it's the brake booster to master cylinder gasket I pulled it and it has two metal plates with a gap I between them could you guys help me

 

[RedFish]

Should be a thin metal plate with a rubber boot chemically bonded to it. Best price I found on reproduction was about 30 shipped. If you have the oval hole or a plate with oval hole a clutch rod boot would work.