Brake booster

[eskimomann209]

Was swapped out yesterday. My 1973 c10 got a fresh booster yesterday.
I have a verrrry high pedal and big feet. The pedal is definitely higher than it was before and has quite a bit of free play before actuating the brakes.

The booster to pedal rod... if this is “lengthened” does this lower the pedal/ free play?

and the booster to master piston... this just adjusted When the pedal transfers to the master? Extending it out toward the master causes quicker engagement?
Just want to be sure I am armed with the proper adjustment theories.

Booster was replaced due to a slight whistling sound emitting from it while driving.
Please and thank you gents.

 

[C10MixMaster]

Was swapped out yesterday. My 1973 c10 got a fresh booster yesterday.
I have a verrrry high pedal and big feet. The pedal is definitely higher than it was before and has quite a bit of free play before actuating the brakes.

The booster to pedal rod... if this is “lengthened” does this lower the pedal/ free play?

and the booster to master piston... this just adjusted When the pedal transfers to the master? Extending it out toward the master causes quicker engagement?
Just want to be sure I am armed with the proper adjustment theories.

Booster was replaced due to a slight whistling sound emitting from it while driving.
Please and thank you gents.

lengthened will give you a higher pedal up to a point then it hits the pedal stop, shortening it will lowered the pedal ,should be adjusted to rest on the stop. The pin to the master cylinder should be set when it was rebuilt , there is a measurement to set it set it to long and the master cylinder will not work right and to short will give you longer pedal movement.

 

[eskimomann209]

lengthened will give you a higher pedal up to a point then it hits the pedal stop, shortening it will lowered the pedal ,should be adjusted to rest on the stop. The pin to the master cylinder should be set when it was rebuilt , there is a measurement to set it set it to long and the master cylinder will not work right and to short will give you longer pedal movement.

That’s what common sense told me as to pedal height.
I have the rod tightened all the way down and it seems high to me still. Guess I’ll have to live with it.
I was hoping it was one of those situations that was counter intuitive. Alas it isn’t.
Thank you sir

 

[Raider L]

@eskimomann209,

Your pedal should only be between three and four inches from the floor. You shouldn't have more than an inch of travel before you feel resistance. So that should leave a couple of inches or a little less to the floor. If your pedal is higher than four inches something else is wrong. A low pedal could indicate worn pads allowing more fluid to go into the brake caliper.

But your problem is the other way right, you've got to much pedal? You could take a look at the rod coming out of the back of the booster, it may be longer. And C10MixMaster ht about the brake rod length. Something happen there, it shouldn't be that high.

 

[Goldie Driver]

I think the 73 - 80 typically have a higher brake pedal than the later ones.

Somewhere in the early 80s they went to a quicker take up master cylinder ( plastic reservoir) and that may be when the booster changed from anodized to painted black.

Here is a pic of my 1980 which still has the anodized booster ( OE as best I can tell).

You must be registered for see images attach

I had the opposite problem - I tried a painted reman booster a few years ago. Lower pedal height, and the feel was all wrong.

Put the OE one back on.

Hope this helps some.

Britt

 

[eskimomann209]

My issue i think stems from I had a brake pedal booster from a 78 and my truck is a 73. when I was building it I looked at both assemblies and couldn’t remember what came from which.
so I mounted one set I had together. I guessed it was the 73s.
since. Ordered a 73 booster and my pedal is all wrong I’m assuming I mounted the 78s.
So indeed sir @Raider L I believe my rod length is too long. I also believe I bought the single diaphragm instead of a dual. I think my best course of action is to swap this out for the 78style and hope it’s got more correct parts for my application.

But this is all brainstorming off the cuff guesses. But I appreciate all the knowledge given so far. And always appreciate more.

 

[eskimomann209]

I think the 73 - 80 typically have a higher brake pedal than the later ones.

Somewhere in the early 80s they went to a quicker take up master cylinder ( plastic reservoir) and that may be when the booster changed from anodized to painted black.

Here is a pic of my 1980 which still has the anodized booster ( OE as best I can tell).

You must be registered for see images attach

I had the opposite problem - I tried a painted reman booster a few years ago. Lower pedal height, and the feel was all wrong.

Put the OE one back on.

Hope this helps some.

Britt

Hmmmm. That doesn’t seem high to you at roughly 4 1/4?
This is my height. And the adjuster is all the way down
Right around 5

You must be registered for see images attach

 

[eskimomann209]

@eskimomann209,

Your pedal should only be between three and four inches from the floor. You shouldn't have more than an inch of travel before you feel resistance. So that should leave a couple of inches or a little less to the floor. If your pedal is higher than four inches something else is wrong. A low pedal could indicate worn pads allowing more fluid to go into the brake caliper.

But your problem is the other way right, you've got to much pedal? You could take a look at the rod coming out of the back of the booster, it may be longer. And C10MixMaster ht about the brake rod length. Something happen there, it shouldn't be that high.

I guess my question is what am I measuring from? Pedal pad or back of arm, strait down or perpendicular to the pedal?

 

[Goldie Driver]

Hmmmm. That doesn’t seem high to you at roughly 4 1/4?
This is my height. And the adjuster is all the way down
Right around 5

You must be registered for see images attach

Nope - that is the way I remember them. With the new booster, the pedal was too low.

However, it appears that your pedal arm has more if a curve to it, which may explain the difference.