Hi this morning under harsh braking the back cossie brakes i put on my rst locked up, anybody know of any valves i can put on to make this not happen? Cheers

 

I run the in line valves from a ka or fiesta,and i have removed my standard load valves ,my rear disks and calipers are from a focus so maybe slightly smaller aswell. Got the valves on my track car aswell and they work fine on that under heavy braking

 

Hi
do you have any pictures of those line valves? I have exact same problem with rear brakes. Front 4x4 cossie brakes and rear cossie 4x4 brakes with wilwood bias valve.

 

Have you done any changes to the brake lines or just binned the standard compresators an putted the ka valves?

 

The best setup for this is using NON ABS brake lines and compensators off an escort.

You will need a 23 rating master cly and remove all the current lines. ALL OF THEM!

The non abs compensator valves can be changed in angle to allow less or more pressue to the rears.

No mods are required to fit and the parts are available pretty easy.

 

Jano - If you already have a non-ABS setup just adjust the compensators, by rotating them?

 

Thats correct changing the angle will effect the bias.

 

I dont get what u mean or where these are? Soz for bein thick lol

 

I think jano is reffering to these on the left of the picture mounted on the bracket



These are on my 3i as i dont think turbo's have them

mark.

 

I have those on mine, so what angle do you adjust and what way for less rear force?

 

On mine i removed my abs and made up some new pipe work .on my s2,focus rs front brakes and standard focus rear disk brakes



On my track car,this runs st170 front brakes and st150 rear brakes

 

I have them on mine, as mine was an xr3i, but never had abs? So which way do i spin em n how much? cheers

 

If you tilt them so the front of them is facing higher towards the bonnet, you will get less bias to the rear. You will need to mod the bracket slightly to allow the angle change.

 

Do you have any idea why my rear brakes are 10x more powerful than fronts?
In mot station they told that rear brakes are very powerful compared to fronts. I have now wilwood bias valve limiting -59% rear brakes but still in rollers rear are more powerful. There is 4x4 cosworth calibers & 2wd discs in front and 4x4 cosworth 273mm rear discs & calibers.
My master cylinder is ABS rst standard.

 

have you used one fiesta-ka valve to each side on the rears? Makes any difference if i put them after the master cylinder? one to each pipe

 

You need some inline valves. We use some on MX5 race cars from a Mk1 Mondeo.

 

Are you using non abs lines and non abs compensators with your ABS master cylinder.

 

I am using abs master cylinder. First outlet is splitted for front brakes and second output is going rear of the car and there splitted for rear brakes. Between that line is normal wilwood bias valve. There is no more original axle bias abs system valves in use.

 

Antti,

On your master cylinder, the forward most port should be operating your front brakes and the rear port should be operating your back brakes. Is this the case?

 

Simple drawing for you..

First is using an inline bias valve.







Next is using NON ABS lines and Compensators.

 

So driving up hill has the same effect and driving down hill applies more braking force to the rear?
How much do you recommend tilting them by, 45deg, 22.5deg, etc.?

 

It depends on the car weight brakes lines etc etc.. Each car will be very slightly different.

 

Yes one on each side ,on my master cylinder i have only two take off,s one front one rear ,thats why they are here on my cars

 

Nope, forward port is operating rear brakes.
Is there different size brake pistons in master cylinder?

 

willwood brake bias valves has one inlet and two outlets??

 

The front chamber is meant to work the front brakes and the rear chamber works the rear brakes. There is a spring between the 2 chambers and plungers which makes the rears come on first for a brief moment to make the car stable under braking. I think the diameter of the master cylinder chambers is the same but they could be different in terms to length and shape.

If you swap the chambers I can only imagine the problems you could cause.

 

Okay.. if this is FACT i have to modify brake pipe connectors and swap those pipes. I report later when i have done this. There is different thread in each pipe connector i think so i cant swap those directly.

 

Ah Antti, this is probably the reason you are experiencing what you are!! The front port is also larger than the rear port.

Swap them round with some adapting pipes first and have a go.

Lee

 

I have picture here. This is how my brake setup was before modifying it. I am not sure if master cylinder outputs are connected precise as factory built it but you get idea. So based my information and this picture i cannot understand why there is some difference between front and rear output in master cylinder.



And this is my current setup, front brakes powerless and rear brakes too powerful.

 

whats the matter with hand drawn pics ffs. Makes me look like i wasnt bothered. Next time keep it simple




The fronts need their own outlet from the master cly. Not joined like you have from 1 outlet.


Just follow my pics it will work fine.

 

My master cylinder have only 2 outputs..so maybe bit difficult to do that what you suggest.
So do i have to replace master cylinder..

 

So basically your problem is down to the wrong parts fitted pal.

You will need to use a master clyinder from an escort mk3/4. Or adjust/mod the one you have to work right. It comes down to what you are using really. Get some pics up. Do you know what its off.

 

It is original S2 RST with ABS system. 23mm. Fluid reservoir is from non-abs orion.

 

Antti ,have you also removed your standard rear load compensators ,on mine i run standard rst master cylinder ( 2 outlet) abs removed ,standard rear load valves removed and replaced with ka versions ,no lock up no matter how hard the braking on both my cars ,i dont run cossie rear brakes though ,st 150 on one and standard focus rear disks on the other

 

Yes i have removed those. Look picture.
What is interesting i am currently limiting -59% rear brakes and those are still much too powerful, front brakes wont grip unless i press pedal really hard then something happens.

 

Do you have the T piece on the inner wings?

 

I think your problem is that one of your real wheels is thinner than the other and off to one side.

IMO

Both mastercylinder bores should be the same size as originally it was a diagonal split.

I would suggest that perhaps your master cylinder is defective OR you have air trapped, try a seriously good bleed. Using my new master cylinder i had to depress the brake pedal over night to release trapped air.

Im using RS turbo front callipers with with cosworth disks and standard rear drums, all compensator have been removed and replaced with new lines and a willwood bias valve.

My valve is adjusted to around the middle at the moment and all is well.

You can try swapping the MC connections over but im not convinced it will help you, if EVERY thing else fails you could always fit the inline compensator's and your willwood bias but i think you have an obvious problem somewhere.

Rob,