brake booster

[Zvoiture]

I did it I did it I did it!!!! And ON the car, no less! (for those who have not experienced removing a booster in a race car with full cage and seat--it ranks right up there with rear spindle pins...and I'm little!)

Remove master cylinder.

Grasp the rod and move it in and out of it's seat a bit, feeling and listening. If you feel the solid 'click click click' of metal on metal with no 'give', your reaction disk is gone. If it is quiet and 'gives' a bit, it's still there.

There is a blued steel spring-lock-retainer clippy thing holding the gasket around the rod. Put a flat screwdriver under one edge and pry out. It will break at the screwdriver, but it doesn't seem to affect re-assembly. It still holds the rubber boot in nicely.

Under the clip is the rubber boot and a large flat washer. Pull the rod out and all this will come with it. It will resist quite a bit a first.

The rod has a large solid metal base affixed to it. The reaction disk goes between the base and it's seat in the booster. The disk is the same diameter as the base and about 3/16" thick solid rubber.

I repeated the above steps with another booster I had (one that didn't hold vaccuum) and there is liberal grease on the base and the disk sticks to it and will come out with it.

With the reaction disk firmly affixed to the base of the rod with the grease, just re-insert.

Put the metal washer and rubber boot back on and snap in the--now broken--retainer.

Re-install the master and bleed.

15 minutes!

I have not applied vaccuum yet, but the pedal feel is worlds better.

steve

[Tourniqet]

you need to bleed the brakes after doing this ???

[Bambikiller240]

Steve removed the master cylinder, so he must have had to bleed upon reinstallation. Right, Steve?

Let us know the final confirmation that all is well!

[Zvoiture]

Yeah, I pulled the master. I suppose you could just unbolt it and bend it out of the way, but it seems like a lot of stress on the brake lines.

I suppose if you just bleed the master and not the wheels there is only the possibility of a bubble between the bottom of the master and the top of the brake lines. On a street car it might not affect much and might even work it's way out. This is a race car and the fluid takes a lot of stress, and gets cooked quickly. With those kind of temperatures inside the lines, you don't want any air (air=moisture). I bleed my car every day so its no big deal. With the right tools, it only takes a second.

I'll probalby drive it tomorrow, and I will let you know if it works.

steve

[Zvoiture]

And just think: When I sel this car, I can advertise: TWO REACTION DISKS!!!

steve

[Tourniqet]

oh, ok

I just pulled the master cylinder to the side...

I suppose it was a lot of stress but. I dont think it hurt anything...

[Ed]

Is a larger brake booster better? In my 72 it's about 8" in diameter and in my 73 it's about 10" in diameter.

[ChrisA]

Hey Ed, nice new avatar. Yes, bigger is better as long as your not concerned with originality. I just replaced the smaller one on my 72 with the big one. Works great.

Chris