Wazzzer

I'm getting my car back 2moro but I've just had a phonecall from the bloke doing it and he's not convinced the Cos 4 pots are as good on braking as they should be, and I'm wondering if the master cylinder needs to be replaced for a better one?

Brakes are: Cos 2WD 4 pots up front, Cos 2WD rear disc conversion, standard RST master cylinder

Any help appreciated

Oranoco

Do you still have the ABS on as this can deaden the feel of the pedal. The brakes on the Escort aren't overservo's like they are on most moden cars which can give the illusion of them not working that well. They just tend to require a little more pedal force to get em working.

zvhturbo

The RST master cylinder is actually very big, so is capably of pushing enough fluid. This is however aslo its downfall.
The larger the master cylinder the moer effort is required to brake the car.

I fitted ST170 brakes on mine and a MK4 fiesta servo and master cylinder, the brakes are fantastic and much more responsive and easier than the standard ones.

Matt

Gaaables

your getting it back

bet u cant remember what it looks like can ya

Wazzzer

PMSL I know gotta get it in for an MOT now before Xmas

Cheers for the replies, Oranoco, no ABS, ditched that ages ago

Matt, does that require re routing all the pipes to each caliper or can you still use the T pieces on the inner wings?

Also does it fit straight in with the original brace bar bolted to it?

zvhturbo

Depends how your set up is.

Here are some pics of mine fitted.









Matt.

Wazzzer

That looks sweet, I could even block off the 2 oulets that I don't use for my setup anyways

Does it bolt to the bulkhead in the place of the RST one on all the same fixings?

zvhturbo

Not quit,

I had to modify the brackets that hold the servo on the bulkhead.

It was a fairly easy job though and the brakes are better than my Saxo !! Which are very very good.

Matt.

Rossco

I think that is the same master cylinder as iam gonna be using on my S1, I got mine from a MK5 Escort, was a right paint to fit though, had to make all the brackets to fit it to the bulkhead and also had to use all the crossover bar because they are all bigger.

Oranoco

I'm seriuosly interested in this mk4 Fiesta Servo and master cylinder conversion

zvhturbo

Its very easy if your good with a welder.

The most important thing is to ensure the servo arm is in exactly the same place as the old one in relationship to the bulkhead.

Hope that makes sence.

Rossco

I have not got an engine in my bay, all the brake servo and crossover bar is fitted so i will try and get you a few pics tomorrow if you like

Oranoco

My bro is a dab hand with a welder so I'll see if he can sort it for me

Wazzzer

thats me fooked then

Wazzzer

Thanks for the info Matt, but as I'm incompitent with a welder I got no chance of doing that

Anyone got any ideas to upgrade with just bolt on stuff?

I was thinkin along the lines of a 3i master cylinder and using the 4 lines instead of just the 2 and splitting them from the RST cylinder...

zvhturbo

Well mate, something to remember is that the smaller the master cylinder the more powerful the pedal will be.
However you will also get a spongier feeling pedal with a small master cylinder.

My preference would be better and easier to use brakes (small master cylinder).

Matt.

nigel b

ive got a pedal box and that is cool
no silly cross bar/bulkhead flex

zvhturbo

http://science.howstuffworks.com/hydraulic1.htm

That should help you understand what i'm saying

Christian and Beccy

iTrader: (14)

Is that on a Mk4 Escort?? If so, where is it mounted?? There isn't an awful lot of room for a proper pedal box.

I use a Standard 25mm Master Cylinder for my brakes, which are Focus RS Brembo 4-Pots. This is fine, the brakes are very good.

Changing to proper TFE Brake Lines throughout and a decent brake fluid makes a big difference.

Wazzzer

I've just driven the car back and I think I know whats up with it, the servo is shite lol

I could hear a nasty hiss when the brakes were applied when my head was in the engine bay, and if I slightly let me foot off then re-apply the brakes it firms up and bites lovely.

Any ideas on cost for a new servo and master cylinder?

Wazzzer

Rick

it'll be the seal between the servo and master cylinder - servos rarely fail.

Wazzzer

Hmmmm thinking about it, I think I know when all these problems started, when the knob cheese who owned the car before fitted the stainless servo cover so you may well be right Rick, some further investigation needed I think....

zvhturbo

Wes you will find two seals between the servo and the master cylinder.

1, A small "O" ring around the base of the master cylinder, THIS IS NOT A SEAL, ITS THERE TO STOP DIRT INGRESS ONLY, there is a small notch in the bottom of the master cylinder to release any lost fluid, because of this the master cylinder should not be sealed to the servo.

2, a larger seal just within the servo. this is about 35mm in diameter and seals the servo from air loss.

Matt.