Installing Replacement Brake Booster 1980 Spider

[mbassler]

HI,

I ordered a new booster from Vick's, when it arrived everything looked fine except a different design of the clevis that attaches to the brake pedal. The dimensions look about the same, but the clevis and hole in the brake pedal aren't even close. I can figure out why such misalignment when every thing it assembled? The booster is orientated correctly and flush against the firewall. I can not pull the clevis down enough to get the pin back in and I am afraid it will bind. The other option is to remove the pedal and drill a hole in-line with the booster clevis?

Any thoughts

Max

[mbassler]

With fresher eyes and more coffee I discovered that the booster mounting plate (to the firewall) is ever so tapered. If you put it on correctly then all is good. Hopefully someone else won't make my stupid error

Max

[mbouse]

i recently installed a replacement brake booster twice in the same hour.

did not see that the exiting booster had a thick rubber gasket between the booster and the firewall until the booster was safely on the workbench and the replacement booster was mounted on the car (pedal installed).

since this was my first brake booster change, i was unaware of the gasket until i looked at the old unit.

i guess practice makes perfect.

[pope]

Mike, tell me more. Are you saying the there is a gasket between the booster bracket and the firewall? Mine does not have one. Got a pic.

[mbouse]

nope, no picture. sorry.

foam rubber, and from memory....
about 1/2" thick tapered bottom to top, roughly 1/8";
about 5" o.d. and 4 1/2" i.d.

i believe it is there to keep dust and grime from entering the cockpit from that gigantic hole needed to get the booster rod & rubber boot into the passenger compartment. doesn't compress much, and serves no other purpose that i see.

the booster bracket compresses the foam gasket to the firewall.

[pope]

Thanks.

[manoa matt]

Mike you installed a genuine original Fiat brake booster. Its removal and re-installation is straight forward as there is no adjustment of the pushrod to pedal connection.

The replacement boosters from Vics and IAP have two distinct differences in the design from original boosters. The biggest difference is the mounting studs for the intermediate mounting plate, the other is the adjustable length connection to the brake pedal.

On the original booster the mounting studs on the booster are about 1/2" long and threaded all the way down. The intermediate mounting plate mounts directly to the booster then the rubber doughnut gasket seals it against the firewall.

On the replacement boosters the mounting studs are about 1 inch long but the threaded portion only extends about 1/2". You could place the intermediate mounting plate direclty against the booster and use washers to take up the space where there is no thread on the stud and then install the nut. This will not work since the studs are too long and the intermediate plate will not sit tight against the firewall. It still will not work if you cut down the studs.

The only way to mount one of the replacement boosters is to use some 3/8" thick washers between the booster and the intermediate mounting plate. You need two of the rubber doughnuts, one between the booster and mounting plate, and one between the mounting plate and firewall.

That is the reason for the adjustable linkage.

[pope]

My mistake, I thought when you said gasket, there was something that went around the outer area where the 4 bolts attach to the firewall. As soon as Matt said donut, that rang a loud bell.

[mbouse]

sorry. Donut... not gasket.

Matt... you are confusing two people. the original poster had an installation issue with an aftermarket booster.

i had no installations issues except i forgot the DONUT (not gasket) the first time i installed.


can anyone else claim completely installing the same brake booster on the same car two times in the same hour?

[manoa matt]

I knew there was two different people, I guess my post was not clear enough. Mike, I'm sure you did not have installation issues because you installed an original Fiat booster. It's the aftermarket ones that have problems. I think its pretty much standard practice to install the booster twice, there is always something that gets forgotten. You got to glue that doughnut to the intermediate bracket first.

[mbouse]

yeah, i recall Denise having some issues with the aftermarket boosters.

glue? i'm not taking that booster off a third time to add glue to the donut...

[manoa matt]

What about glazing and sprinkles?

[mbouse]

now that, i could go for!! cup of coffee too.