Mk3 rear master cylinder rubber boot

A

andre1

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Jun 23, 2017
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Guys
Hopefully not too silly a question - how do I replace the rubber boot on the rear master cylinder? Does that adjuster bolt just disassemble or do I have to remove the whole m/cyl?

Thanks, Andre
 
andre1 said:
Guys
Hopefully not too silly a question - how do I replace the rubber boot on the rear master cylinder? Does that adjuster bolt just disassemble or do I have to remove the whole m/cyl?

Thanks, Andre
Click to expand...
That boot needs replacing often . I unclip the pushrod assembly , remove the torn old one and slide on the new one using massage and grease .
 
Gotcha.
I removed the 11/16 AF nut that the boot goes into (taking care to measure where it sat on the pushrod) and replated it, then reinstalled in hopefully original position. Gonna be tricky to get the boot onto the master cylinder and that nut thing.

I guess one could do boot onto m/cyl then install the nut, or boot onto nut then screw nut into place and try to persuade boot onto m/cyl.
Might have a beer first to think about it, and see what advice pops up...
 
andre1 said:
I removed the 11/16 AF nut that the boot goes into (taking care to measure where it sat on the pushrod) and replated it, then reinstalled in hopefully original position. Gonna be tricky to get the boot onto the master cylinder and that nut thing.
Click to expand...
The nut must be set to:
Mk3 rear master cylinder rubber boot

I think I only ever slid the boot over the nut.
 
Hi. I have a related question. Recently I invested in a 13mm master cylinder made by L.F. Harris for my Mk3 build ( I will be using CNW's Brembo caliper). I need to install the pushrod, which I bought separately. Do I have to dismantle the MC for this? And if so, how do I proceed? I am a complete newbie on Norton's hydraulic brakes .....

Thanks,
Knut
 
mdt-son said:
Hi. I have a related question. Recently I invested in a 13mm master cylinder made by L.F. Harris for my Mk3 build ( I will be using CNW's Brembo caliper). I need to install the pushrod, which I bought separately. Do I have to dismantle the MC for this? And if so, how do I proceed? I am a complete newbie on Norton's hydraulic brakes .....

Thanks,
Knut
Click to expand...
Knut,
FWIW I just removed my Harris from the rear brakes. Although it improved the braking power I found the increase in the pedal travel was too much. I have rear sets on mine and the pedal was so high up I had to lift my foot completely off the foot rest in order to reach it. Not too much of a problem for regular riding, but when getting into twisty roads it was a pain. Every time I had to lift my foot off the footrest it upset the line of the bike. It was a very unsettling situation. I primarily use my front brakes, but by habit I put my foot over the rear just in case. I re-installed my original and like it better.
Just my .02 cents. What ever you do I wish you luck.
Pete
 
CP3812 - 737 , A.N. Part . Order in several , hard to find , often sold out . Older notes , maybe updated now .
 
ah - I put the boot onto the m/cylinder, but with the m/cylinder insitu it seems awfully tricky to persuade the boot over the nut. Am I dreaming and need to remove the whole master cylinder to get the boot on?

Andre
 
update.

In the end it transpired that the master cylinder was leaking so had to come off for a seal kit etc. No surprise after 49 years... Then easy to install new outer boot.
I did notice that the kickstarter bolt had been hitting the outer rubber boot due partly due to the kickstarter pinch bolt head having two washers under it. I see the parts book shows no washer fitted so I'm about to remove them an hope that gives enough clearance.
Be good if the master cylinder was a trifle higher up from the kickstart but I see no way to do that (unless the footpeg gets bent up a bit higher..)

Andre
 
Grade 8 bolt with one washer .
Grease rubber before install .
Good luck on the new master cyl . rebuild .
AN sells a new 13 m . improved one albeit not cheap .
When mine eventually fails , I will order it in then .
I lubricate the push rod regularly with grease , never a failure , except the rubber cap you talk of .
Mind you , I grease up just about everything that moves .
 

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