Brake master cylinder.

[steve-V8s]

The braking system is dual circuit, with a pair of pipes to the rear and a pair to the front.

In the master cylinder is there one piston or two, or one piston with two seals on it ?

[phillpot]

The power of Google .............

[BIG DUNC]

On mine there is a pair of pipes going to the front and a single pipe going to the rear which T's off at the diff.

Sorry, cannot help you with what is going on inside the master cylinder.

[steve-V8s]

Excellent, thank you for that.

Next question, how do you access it ? Had the Griff for around 15 years and the brake master cylinder is probably the only bit I haven't had to attend to, until now.

[roseytvr]

With great difficulty!

It’s on top of the servo in the front wing. You need to get the pedal box out with the servo in place to change it which means upside down in the footwell with your legs in the air, very undignified for blokes of a certain generation!

A real bd of a job but doable with patience

Good luck👍

[phillpot]

Personally it's one of the few things I'd leave well alone unless you have an issue?

if you can reach in and feel the front of the servo, below where the master cylinder bolts on and it is damp or the paint is bubbling and loose then yes it is weeping and needs attending to

[steve-V8s]

The pedal goes to the floor, the fluid is not going down and can't see a leak anywhere so have to assume the fluid is simply circulating around inside the cylinder.

Seat out, upside down time I think.

[RobXjcoupe]

steve-V8s said:

The pedal goes to the floor, the fluid is not going down and can't see a leak anywhere so have to assume the fluid is simply circulating around inside the cylinder.

Seat out, upside down time I think.

Mine did that a few years back whilst driving. Well once the master cylinder was removed my particular master cylinder part was from a mk3 fiesta diesel. Luckily my servo was fine. I gave the pedal box a shot blast then a few coats of zinc primer and satin black on top. Looked like new when it all went back together

[TJC46]

steve-V8s said:

The pedal goes to the floor, the fluid is not going down and can't see a leak anywhere so have to assume the fluid is simply circulating around inside the cylinder.

Seat out, upside down time I think.

Here is a detailed description, at the bottom of the page, of my attempt.

https://www.pistonheads.com/gassing/topic.asp?h=0&...

Good luck, this is by far the worse possible job i have ever had to do, but being brakes its vital to sort it properly.

My problem was a failed servo.

[Barreti]

This is a complete bd of a job and one which I swore if I ever had to do it again I would just cut the inner wing open a bit wider and either reglass it back or make a better cover.

You need an enormous amount of patience, a 3/8ths socket set with extensions and a wobble and a couple of small spanners
The 3/8ths socket stuff is for the nuts which hold the cylinder in place.
Oh, and put a bit of string on the spanner you use. Its not funny if you drop it.

[steve-V8s]

Barreti said:

Oh, and put a bit of string on the spanner you use. Its not funny if you drop it.

Bit of string tied to spanner is indeed a top tip.

[Sardonicus]

If you remove the clutch master cylinder 20 minutes tops then brake master renew is a piece of piss

[steve-V8s]

Are you suggesting that with the Clutch master removed the brake can be accessed via the hole in the wing ?

I may be able to get to the fixings onto the servo but not convinced about all of the pipe unions.

[Sardonicus]

Yep re-sealed brake MC as preventative maintenance 3 years ago when I built the engine along with the clutch master and slave cyl's , I also suggest removing drivers footwell carpet and underlay ect so that any residual fluid that leaks from the master cyl res as you pull it out can be soaked up then just dilute with hot water it will all just end up in the footwell where you can wick it up with kitchen towel or an old bathroom towel etc, no potential then for paint damage to pedal box servo etc

[steve-V8s]

How is the reservoir attached to the cylinder, are there some fixings I can't see or is it just a case of pulling harder ?

[phillpot]

steve-V8s said:

is it just a case of pulling harder ?

you got it

[steve-V8s]

As said, it can be removed without taking out the pedal box so that was good advice.

Disconnect the clutch pedal and remove the clutch master, remove the rubber seal around the reservoir and pop it off the cylinder ( having emptied it first with a syringe )then you can get at the fixings and unions, one of which is easier if you pop out the throttle cable grommet.

Now, question is can I get a rebuild kit or do I have to replace it ?

[phillpot]

steve-V8s said:

Now, question is can I get a rebuild kit or do I have to replace it ?

For the hassle involved I'd go for a new one rather than seal kit.

Master cylinder started to weep on my S Series (far more accessible) a little while back, tell tale paint peeling on servo. Strip it out, bore looked fine so went for a seal kit. wasn't too long before I got the same tell tale peeling paint
New master cylinder fitted this weekend, pedal has never been so good

[Sardonicus]

phillpot said:

steve-V8s said:

Now, question is can I get a rebuild kit or do I have to replace it ?

For the hassle involved I'd go for a new one rather than seal kit.

Master cylinder started to weep on my S Series (far more accessible) a little while back, tell tale paint peeling on servo. Strip it out, bore looked fine so went for a seal kit. wasn't too long before I got the same tell tale peeling paint
New master cylinder fitted this weekend, pedal has never been so good

Good point mine wasnt leaking and I managed to bag a new old stock genuine Ford kit for peanuts for whats involved new MC assy every time