F

fearofweapons

Member

• Dec 21, 2022

• #1

Hello!
I have an 1990 110. I have just replaced the brake master vacuum servo. The pedal had massive amounts of travel after the replacement. I bled the brakes using an eziee bleed.

The pedal now has 1-2cm of travel before the brakes lock up.

Is there an adjustment I can make to give me a bit more travel? It feels as if I so much as look at the brake pedal I lock up!

I have seen posts talking about adjust the push rod length but can't find anything to tell me how to do that.

As always any help much appreciated.

Richard

 

landowner

Pensioner Pete

Full Member

• Dec 21, 2022

• #2

.

 

tottot

Well-Known Member

• Dec 21, 2022

• #3

You have peddle return springs in place to bring it to top of its movement?

 

Al2O3

Well-Known Member

Full Member

• Dec 21, 2022

• #4

I wish my brakes locked up

 

bankz5152

Well-Known Member

• Dec 21, 2022

• #5

I would double check you have bled it correctly

 

robbie the greatl

Active Member

• Dec 21, 2022

• #6

there is ajustment on the rod in the master cylinder it has a locknut on it try to adjust it it may help

 

F

fearofweapons

Member

• Dec 21, 2022

• #7

Sorted.
To adjust the point at which the brake pedal bites....

1. Remove the master cylinder from the vacuum servo by undoing the two nuts holding it on. You can leave the brake pipes connected. There should be just enough room to remove it past the coolant expansion tank.
2. Now have a helper, either a human or a bit of wood, depress the brake pedal. This will cause the push rod to extend from the servo.
3. Depending on the type/age of the servo you can use spanner to hold the inner nut or a pair of mole grips to grasp the shaft - then using a socket spin the end nut ( which is part of a threaded bar ) to adjust the length of the rod as required.
4. Reassemble ( don't forget to let the brake pedal up! )
5. Test.
6. Repeat until the amount of travel is acceptable.

I am sure there is another, more scientific, way to do this that does not involve repeatedly removing and replacing the master cylinder; I was up against encroaching darkness and needing to make tea for the family so could not spare time to do the research. Happy to be educated though!

This will only 'fix it' if you have minimal brake travel and your brakes lock up. If you have lots of travel and non functioning brakes you have, probably, not bled them enough / have other issues.