Brake master cylinder....

DD · Posted: Sun Feb 11, 2007 2:58 pm Post subject: Brake master cylinder....

Right folks,
It's about time I did my brake master cylinder to get some pressure back (instead of pumping up my brakes t come to a halt!!!).

Instead of farting about with an overhaul kit, thought it prudent to simply replace the whole cylinder.

Seems an easy job, as the new cylinder comes ready to fit (I think).....but are there any dodgy areas to look out for? As far as I can see, it's simply a case of:-

drain reservoir.
undo brake pipes and tape-up.
remove cylinder
replace with new, and new o-ring.
back on with the pipes.
bleed system.

what can go wrong!? Rolling Eyes

DD · Posted: Wed Feb 14, 2007 10:09 pm Post subject:

can't believe there's been no replies.........god damn!

ad90 · Posted: Wed Feb 14, 2007 10:16 pm Post subject:

Sounds about right, although it all depends how you hold your spanner

Laughing

AD90

Winnet · Posted: Wed Feb 14, 2007 10:16 pm Post subject:

I'm sure it is nothing personal DD!!!

Presumably it is a case of doing it the way you suggest as long as you don't press the brake pedal once the pipes are disconnected, it is amazing the amount of fluid in there.

I have a flaring kit and pipe if you need any.

G.

DD · Posted: Wed Feb 14, 2007 10:31 pm Post subject:

oi! AD...hear congrats are in order? Very Happy

ad90 · Posted: Wed Feb 14, 2007 10:49 pm Post subject:

Thanks DD, Yes another Wee Girl, should get her and Mom home tomorrow. And at the risk of attracting smutty comments; how is your little one doing?

AD90

PS. You know what I was getting at with the spanner jibe Laughing

imatthew · Guest

The hard bit is simply getting all the air out of the system once you have put it back together.

DD · Posted: Thu Feb 15, 2007 7:15 pm Post subject:

thanks all Very Happy

AD - very well indeed cheers. Smile

w3526602 · Posted: Fri Feb 16, 2007 5:45 am Post subject:

Hi,

Provided you only break into the pipe work at the master cylinder, its possible that the pipes wil remain full. So when you have fitted the new cylinder, bleed the unions to the MC first....so any air is close to those unions, then tighten. Next, slacken off all the adjusters. Reverse flow of fluid will push air back through the MC. Maybe!

Sorry, I didn't notice what truck you have. If it has disc brakes, then lever the pistons back into the calipers to get same effect. I had to do this regularly on my son's first car which had a terrific (but unexplained) thirst for fluid. Much easier than doing a full bleed when the MC went empty.

I leave it to you to make your own arrangements to avoid fluid on your paint.

In passing, I have a theory. If you open up a brake pipe, all the fluid drains out of your MC. Advice is to cover filler hole in reservoir with cling film, to prevent air getting in, so fluid does not want to get out. My idea is that if you depress the brake pedal, it closes to check valve in MC, so fluid cannot get out of the reservoir. Thats the theory. I practice, I found that it did not work with tired seals. Any comments?

602