Honda-SOHC

SOHC.co.uk Forums => CB750 => Topic started by: Drew400 on December 14, 2016, 08:17:12 PM

Title: 750 F2 Rear Brake weeping fluid
Post by: Drew400 on December 14, 2016, 08:17:12 PM

Hi all,

It's been a while...

I have noticed a very small pool of brake fluid underneath the 750's brake pedal when parked up in my garage (coz I ain't going far in UK winter!) .

I suspect it's from the master cylinder that probably needs a refit of plunger rubbers, etc. It might simply be the jubilee connectors from the hose.

As you can tell, I haven't yet started to strip any parts to take a proper look, but it occurred to me that some of the experts on this forum may have experience and tips where to look first, what not to touch, etc.

Any thoughts much appreciated as always.

Cheers,

D.

Title: Re: 750 F2 Rear Brake weeping fluid
Post by: Johnwebley on December 14, 2016, 10:42:39 PM

might be a good idea to clean as much as possible,
 then dust it with talc,not only will it smell better, but should show were the leak is !!!


 

Title: Re: 750 F2 Rear Brake weeping fluid
Post by: Drew400 on December 16, 2016, 05:22:53 PM

Nice idea, John, ta.

Wonder if I'll get some unwanted (now wanted) talc for Christmas!

Cheers, D.

Title: Re: 750 F2 Rear Brake weeping fluid
Post by: K2-K6 on December 16, 2016, 06:37:12 PM

They generally get quite a small amount of movement regarding piston stroke even if regularly used so the seals seem to harden enough to get slightly too poor to give a clean seal.

I've got a low use disc rear brake on a bike at the moment which when stationary I give it a real strong squeeze that seems to avoid problems generally.

They just don't move the fluid around enough to keep them exercised very well compared to the travel you get onto the front lever and piston.

Sounds like as you say it's a strip, clean and re-seal job with new fluid.

Title: Re: 750 F2 Rear Brake weeping fluid
Post by: Drew400 on December 18, 2016, 10:57:23 AM

Thanks again, all helpful stuff. Cheers, D.

Title: Re: 750 F2 Rear Brake weeping fluid
Post by: Drew400 on January 18, 2017, 04:56:52 PM

I forgot to finish off this thread by saying, all sorted and working nicely.

Pretty simple job once I cleaned off all the road crap mixed with grease in and around the broken rubber boot. Truth is, I like cleaning bits of old bikes... I guess I'm not alone on this forum, eh?

During and After pics inserted for anyone interested.

Cheers all, D.

Title: Re: 750 F2 Rear Brake weeping fluid
Post by: Green1 on January 19, 2017, 09:05:30 AM

The only problem with fitting clean parts is it shows up something else next to it and before you know it the bikes in bits again.

Title: Re: 750 F2 Rear Brake weeping fluid
Post by: Drew400 on January 19, 2017, 09:08:07 AM

Ha ha, good point. That's why I always fettle my bikes with my eyes shut!

Title: Re: 750 F2 Rear Brake weeping fluid
Post by: Green1 on January 19, 2017, 09:17:31 AM

Don't make the mistake of putting them on a bike bench you see everything that hasn't been washed for the last 40 years  :o
All mine are taking turns on the bench having a good scrub at the moment