Power booster question

[Llamaback]

Hi all, I have a question about the bendix power brake boosters.. I have a bendix power brake booster that I bought from Dr Diff and I measured the stroke that the pushrod coming out of the booster travels and it is right around 1.185'', (I measured this with the booster on the car and also just now off the car, with no vacuum being applied to the booster. The stroke of the master cylinder I am wanting to use is right around 1.430'' (Dorman M75818). So the bendix pushrod is a quarter inch short of being able to push the master cylinder the full length of its stroke. I measured the stroke of the master cylinder with no fluid and used an old brake pedal pushrod to get the measurement. Shouldn't the stroke length of the booster pushrod be able to bury or bottom out the master cylinder stroke at full travel?

Does vacuum being applied allow the booster pushrod to have more travel?

the aluminum master cylinder I got in my Dr Diff kit has a stroke length of 1.260'' so the booster pushrod still comes up short with this one

My original drum drum 1970 master cylinder has a stroke length of 1.115" so the booster is able to bottom this one out.

Am I over thinking this? I emailed Dr Diff this question but have not heard from him in almost two weeks. Thanks for any input!

 

[chrger1967]

Hi all, I have a question about the bendix power brake boosters.. I have a bendix power brake booster that I bought from Dr Diff and I measured the stroke that the pushrod coming out of the booster travels and it is right around 1.185'', (I measured this with the booster on the car and also just now off the car, with no vacuum being applied to the booster. The stroke of the master cylinder I am wanting to use is right around 1.430'' (Dorman M75818). So the bendix pushrod is a quarter inch short of being able to push the master cylinder the full length of its stroke. I measured the stroke of the master cylinder with no fluid and used an old brake pedal pushrod to get the measurement. Shouldn't the stroke length of the booster pushrod be able to bury or bottom out the master cylinder stroke at full travel?

Does vacuum being applied allow the booster pushrod to have more travel?

the aluminum master cylinder I got in my Dr Diff kit has a stroke length of 1.260'' so the booster pushrod still comes up short with this one

My original drum drum 1970 master cylinder has a stroke length of 1.115" so the booster is able to bottom this one out.

Am I over thinking this? I emailed Dr Diff this question but have not heard from him in almost two weeks. Thanks for any input!

I just ordered this to check if there is any play from the booster in the M/C. My pedal feels like there is some travel in it until the brakes actually apply. They feel good once the do, but I’m hoping to find that the for only needs an adjustment.

 

[68 Sport Satellite]

I just ordered this to check if there is any play from the booster in the M/C. My pedal feels like there is some travel in it until the brakes actually apply. They feel good once the do, but I’m hoping to find that the for only needs an adjustment.

View attachment 1911999

when you use that tool, the gap between the booster pushrod and the MC bore plunger face is supposed to be adjusted to .050". This gap prevents touchy brakes. The tool works great and takes the guesswork out. You'll still need a feeler gauge for the .050" distance and the measurement is taken with the MC unbolted from the booster.