Master cylinder. How to change

[grumpy2]

My brake fluid has been dropping slightly without any sign of a leak anywhere. I've spotted a slight oil it's around the joining face between the master cylinder and servo. This may explain why there is no sign of a leak if the master cylinder is weeping into the servo.

So changing it is on my to do list. Looks like I have three options. Put new seals into my existing master cylinder, buy a resleeved one for £120 or buy a 'new' one from paddocks for the same price

Which route would folk recommend? Info based on experiences would be great thanks

Gary

[Rubce]

Hi Gary

I did that job on our Stag in February. I went the new unit from Paddocks route. Touch wood it is working well to-date! I dismissed the idea of simply replacing the seals as the thought of refitting everything and bleeding the brakes only to find it might still be leaking filled me with dread.

Regards

Bruce

[Mike Stevens]

I did the same as Bruce last year. I did first try changing the seals, but it is not easy and my old cylinder was pretty grotty inside anyway. You need some very long nosed circlip pliers - and even then it's no picnic!

Cheers,
Mike.

[ukbiggles]

I too did the same as Bruce about 18 months ago - a new unit from Paddocks. Straightforward job and still working well

Cheers

Gord

[blue 464]

I did mine recently with a new unit, simple job, no need to remove the servo, Derek

[grumpy2]

Thanks chaps. I'll go for a new one. Is the fluid dot 4 or 5?

Gary

[Rubce]

Thanks chaps. I'll go for a new one. Is the fluid dot 4 or 5?

Gary

Gary

That depends very much on what is already in the system as you are not supposed to mix the two types.

Regards

Bruce

[grumpy2]

Hmmm. How do we know? I've been topping up with dot4 so I guess I'll just use that

[Seaking]

DOT 5 is purple in colour.
I rebuilt mine at the start of the year still going strong.
Cheers Glenn

[Goldstar]

I just came in from the garage having bled my brakes with dot 5.1 and it was yellow!

[jleyton]

I just came in from the garage having bled my brakes with dot 5.1 and it was yellow!

So is the Halfords DOT 4 that I've just used to renew all of my brake fluid

I was pleasantly surprised at just how easy it all went, doing it on my own with just a pipe and jar (two pipes actually as front and rear nipples are different sizes)

I bought 5 litres, as it was pretty cheap with my trade card, and used less than two, despite using the fluid to flush it all through.

Cheers

Julian

[jleyton]

I just came in from the garage having bled my brakes with dot 5.1 and it was yellow!

DOT 5 is purple in colour.

Be aware:

There are two main types of brake fluids:
* DOT 3, DOT 4, Super DOT4* and DOT 5.1 which are based on poly glycol compounds.
* DOT 5, which are based on Silicone.
Note the two types of fluid are not compatible and must not be mixed in a braking system.

[Goldstar]

Be aware:

There are two main types of brake fluids:
* DOT 3, DOT 4, Super DOT4* and DOT 5.1 which are based on poly glycol compounds.
* DOT 5, which are based on Silicone.
Note the two types of fluid are not compatible and must not be mixed in a braking system.

That makes sense - yellow DOT 4 and DOT 5.1 good, anything mixed with DOT 5 (except DOT 5, of course) bad.

[Gresley]

Hi Gary

A few years ago I took mine apart to renew the seals but as it was rough inside I bought a new one from Paddocks, so far it has been good and has been on for about 40,000 miles. I also use DOT 4 fluid.

Brian.

[grumpy2]

Ok dot 4 it is and one of paddocks finest for figment of Xmas.

Thanks

Gary