Bendix Brake booster

[mpro69rr]

Hey Guys,

When doing the engine bay in my 69 RR 383 4 speed, I installed a Bendix brake booster. For those of you that have one, before bleeding how far until your brake pedal bottoms out? Mine bottoms out about half way down, is this correct? I'm trying to bleed them now and it just about bottoms out before stopping (yes, I bench bleed the booster). Thanks Guys!

 

[snakeoil24]

Did you install proper push rod

 

[Jonas Nordstrom]

Bottoms out as in no more travel in pedal linkage/cylinder travel? I have a new bendix and before bleeding it could travel down to the floor.

 

[mpro69rr]

Did you install proper push rod

Yes, but I had to have it lengthened because it was too short.

 

[mpro69rr]

Bottoms out as in no more travel in pedal linkage/cylinder travel? I have a new bendix and before bleeding it could travel down to the floor.

Really, did you have to do anything to the rod? Yes, bottoms out as in no more travel. Not sure if there is more travel in the cylinder or not. Where does your pedal sit, is it even with the clutch pedal

 

[Jonas Nordstrom]

No, used the original linkage/rod. Mine is an auto and the brake sits a tad higher than the gas pedal.

 

[mpro69rr]

No, used the original linkage/rod. Mine is an auto and the brake sits a tad higher than the gas pedal.

View attachment 1176208

I think on a standard the brake pedal sits a lot higher, that would explain why yours hits the floor. What's the travel length to the floor?

 

[Jonas Nordstrom]

I think on a standard the brake pedal sits a lot higher, that would explain why yours hits the floor. What's the travel length to the floor?

Yes, manual sits higher.
With the booster it sits lower, though after a ton of reading on different forums I found that this is normal and factory correct.
When driving the brakes works perfectly and I´ve got some travel left when standing on the brake.

Edit: From the back of the metal chrome edge on the brake pedal I´ve got 11cm to the floor.

 

[mpro69rr]

Yes, manual sits higher.
With the booster it sits lower, though after a ton of reading on different forums I found that this is normal and factory correct.
When driving the brakes works perfectly and I´ve got some travel left when standing on the brake.

Edit: From the back of the metal chrome edge on the brake pedal I´ve got 11cm to the floor.

Thanks for your help, I have about 3-4" of travel before it bottoms out, this sounds about right I guess.

 

[mpro69rr]

What's the travel everyone else has before you bottom out? As the above post says I have around 3 - 4" of travel before bottoming out, is this correct?

 

[Jonas Nordstrom]

Thanks for your help, I have about 3-4" of travel before it bottoms out, this sounds about right I guess.

No problem, hope you get it working.
Also, with the booster the brakes engage quite far down in the travel, though this is also normal according to many forum posts. (Though takes some getting used too.)

 

[mpro69rr]

No problem, hope you get it working.
Also, with the booster the brakes engage quite far down in the travel, though this is also normal according to many forum posts. (Though takes some getting used too.)

Yes, that's what happens to mine, great info thanks!

 

[mpro69rr]

Resurrecting my thread. I found the booster was loose which gave me a tiny bit more travel. It still doesn't feel right. Its very touchy and stops but bottoms out. I had rod that attaches to the brake pedal lengthened because the brake light switch wouldn't' touch the pedal. Any more ideas why I have such a short travel? Do I need to adjust the rod that goes into the M/C?

 

[Fran Blacker]

There's suppose to be .020 clearance from rod to master cylinder plunger. If there's more your pedal will be lower. There's a small acorn like nut coming out of booster to adjust the clearance.

 

[Demonic]

I had rod that attaches to the brake pedal lengthened because the brake light switch wouldn't' touch the pedal.

Just wondering how that was done? Usually the bracket or switch is where you adjust the brake light switch. If you threw off the geometry, it could cause the problem you're having. Fran is correct on his reply above. If the MC pushrod is too long, the brakes can drag - not release fully.

 

[mpro69rr]

There's suppose to be .020 clearance from rod to master cylinder plunger. If there's more your pedal will be lower. There's a small acorn like nut coming out of booster to adjust the clearance.

I didn't know there was an adjustable nut, I will look into that, Thanks!

 

[mpro69rr]

Just wondering how that was done? Usually the bracket or switch is where you adjust the brake light switch. If you threw off the geometry, it could cause the problem you're having. Fran is correct on his reply above. If the MC pushrod is too long, the brakes can drag - not release fully.

They cut the rod and put a sleeve on it and welded it. I read a lot of posts where people where doing different things because they ran into the same problem with the Bendix booster, the rod would not reach the brake switch even with adjustment. if the switch was moved a lot where I could use the original rod the same thing would happen and the brake pedal would be lower and not even with the clutch. I'm going to look at Frans idea.

 

[Fran Blacker]

 

[Fran Blacker]

Then you need to measure depth of hole in master cylinder and adjust nut for .020 clearance.

 

[mpro69rr]

Then you need to measure depth of hole in master cylinder and adjust nut for .020 clearance.

Thanks, I just ordered the tool for that, not sure how to use it but I'll learn.