English French German Italian Spanish

Front brake lever

Submitted by keith_bliss on Monday, 2 December, 2024 - 13:57
Forums
Commando

Hi. 1973 750 with hydraulic front brake. I have drained down the master cylinder to replace hose etc. I removed the lever to paint the master cylinder but now I am having trouble refitting the lever. I cannot seem to get the master piston to depress enough to fit the pivot bolt. If I get it close I think the piston is so depressed that the brake wont operate anyway.  Can a piston get stuck? Should I try and rebuild the master cylinder?  Or, is there a knack I am missing? Thanks.
 

Submitted by stan_thomas on Monday, 2 December, 2024 - 19:17

Permalink

You should be able to push the piston in with your finger. So, normally, you will push the heel of the lever against the end of the piston and drop the pivot bolt in.

A couple of possibilities occur to me:

  1. you've let the piston come too  far out of the bore and the seal is trapped on the outer lip. If so, take it apart, clean and reassemble. If it warranted paint then maybe some new seals wouldn't go amiss.
  2. you're trying to push the piston in against hydraulic pressure 'cos you've blanked the end of the master cylinder or reconnected the hose.

Thanks very much. I have connected hose, bt no fluid, and switch so that's a possibility. New seals may be in order as you say. Just had a cataract  op so will try in a day or so!

Submitted by keith_bliss on Tuesday, 3 December, 2024 - 14:38

Permalink

I will dismantle and investigate out of interest but I have decided to take the opportunity of upgrading to the Andover 13mm option. Thanks again for your help.

Submitted by francis_vidril1 on Thursday, 5 December, 2024 - 15:56

Permalink

It's a very good choice, and will significantly improve braking, as it's the original master cylinder that's mainly responsible for very poor braking.

 



© 2024 Norton Owners Club Website by 2Toucans