original

Hi all

I've been looking at how the brake system works on the cosworths as I want to use this on a different vehicle (non cosworth) in order to remove the brake servo to free up space.
From my understanding and what I've read...

- the front brakes are actuated by the master cylinder alone
- the rear brakes are activated by the pressure stored in the pressure vessel (as created by the pump)

The separate abs block does the control of fluid to each wheel to stop it braking in the event of a skid etc. this was moved to the LH side in RHD cars due to the lack of space and connected by brake lines.

I'm looking at using this system on a car without the ABS control block. I will admit, having never driven a cossie I have no concept of what the pedal feels like, but I would assume its really hard if the front brakes are activated by the master cylinder alone. This would be like driving a car with no vacuum servo. This seems a bit odd for such a popular car.

perhaps you could share your experiences if anyone has removed all the abs from their car?

thanks

Paul

stevieturbo

Pretty sure the electric pump offers assistance to both front and rears, the pedal in a cossie does not require huge amounts of effort.

Not quite sure what you're trying to achieve though ? You actually want to install an entire ABS system from a cossie into another car ?

SMILER258

Why dont you just use a big ghia/xr4x4 non abs servo?

original

Cant install servo because I have no space so looking to use other parts. Not interested in the abs part but I understand the pump+pressure vessel and mastercylinder can be mounted apart.

Was hoping for a more comprehensive explanation into its workings....

Caddyshack

I am doing the conversion now, I am buying a loom from wizziat123 to run the pump. The pump feeds the master cylinder and you can house the pump and pressure vessel in anothe place. The system can be used without the abs block. I believe that one of the outlets will be blanked and you just use one for front and one for rear in to t pieces. I will try and update you with more as I get it. The pump feeds both front and rear though and you need the loom to control the pump pressure.

mk22door

I did this in my Sierra, but never drove it on the road because I took the car to bits again

Can't remember exactly how it goes but I used everything except the valve block.

The brakes worked around my mates yard but that's all I can tell you

whiteestate

Ive ripped the servo out of my estate and put the cosworth boosted brakes in and kept the abs valve as this also controls the bias to the rear but it is not wired in. The brakes are brilliant and have a really solid feel to it. I have a wiring diagram somewhere from when i made my loom up, i used 2 relays which trigger on low pressure and high pressure quite simple how it works.

doga-ot

iTrader: (1)

Right its easy my saph was non abs, I bought and fitted saph 4x4 cossie abs pump and servo etc then bought a braided loom to run it so I have abs but without all the abs nonsense like sensors, piping, ecu and module. the braided loom has a battery + battery - 2 small wires for abs light in clocks and a ignition live!

Caddyshack

Anyone know which 2 of these 3 to use and if it matters which is front and rear. Which to block and any suggestions as to what to block with. I have been thinking of welding over one of the screw in nipples and then wind it back in. I have a plug for one of the sizes.





Here is a closer shot. There are two small and one large. One is the return or feed for the abs block that I am not using.

dojj

iTrader: (3)

One for the front
One fit the rear
One for the return from the valve block
You've only got 2 so ones missing

Caddyshack

This is my spare master, the one in the car has all 3 but it was easier to take a pic of this one. Everyone seems agreed that I can blank off the middle one...and it seems the far end is the front brakes.

dojj

iTrader: (3)

the middle is the return i'm pretty sure

the front circuit is presurised via the pedal with no assistance if there is no power so you still have brakes

the fronts and boosted when there is power to the pump

the rears are fed a constant pressure when there is power and the pedal is pressed

Caddyshack

Very clever and Thanks. I like the way you can allow the pump to run to bleed the rears..I think you have to bleed rears first Irrc. I will make up the brake lines tomorrow. Much appreciated.

dojj

iTrader: (3)

Yup, bleeding the rears I'd an easy way to change the fluid as it takes about a litre

But the pump run time is limited to 30 seconds or so, it's been a while so it might be longer but I know it's limited to not cause it to burn out or over pressurise

Caddyshack

Rears now all plumbed in, just need to finish off the fronts and run a switched and perm live to the relay and then ready to bleed up, the whole system is upgraded and new with big brakes and top quality pads in refurbed calipers so I hope they are good, I have j hook discs on big bells all round.

mexicossie

Would you mind sharing where I can acquire a loom like what you have? Or is there a diagram of the wiring, I don't have access to any Cosworths to cross reference, would also like to know how to connect the lines. Cheers

bitterend

Has anyone experience of this arrangement with this bock?


I am unable to get the brakes to bleed. When the pump is activated the pedal comes up rock hard with no travel. I can get one circuit to bleed usig the pump pressure, but the other circuit will not bleed because there is no pedal travel.

I removed the block and can see that the front port on the cylinder is ported to the rearmost connector (red line), the second port goes to the front pipe connector ( Blue), the third port (yellow) goes to the middle connector which is the larger pipe fitting, and the last port on the cylinder is blanked off.
The only way to get pedal travel is by releasing pressure on the rear pipe connector (red line).
I think the front brakes should be on the blue connector and the rears on the red, but me well be wrong.
So does anyone know how to connect this without the ABS control unit?
I do have an ABS unit which bolts on to the master cylinder in place of the block, but my understanding is that without the ECU and the rest of the ABS controls the valve block defaults to a closed position thus preventing the rear brakes to work.
Any help much appreciated.

dojj

iTrader: (3)

the pump controls the pressure to the rears and the valve block
if you have an intergrated valve block rather than a seperate one then i'm not sure
one pipe does the fronts, one does the rears and the middle one is the return
if the pedal is rock hard it's most likely to be a relay that's at fault

bitterend

Definatly not the relay. With the Ign off & the relay out and the accumulator pressure released the pedal is still rock hard with no travel until I open the rear brake bleed nipple on one side.
As far as I can work out it is something to do with the block on the side of the M.Cyl. I dont have a schematic of the hydraulic system, but my guess was that the ABS unit dumpped the pressure back to the resevoir until te pedal was depressed and then the abs return valve shut.
But as I say it was only a guess.

Having torn out what little hair I have left I am solving the problem by replacing the whole master cylinder/pump assy with the master cylinder from a Tesla. That uses an electric motor to boost the pedal effort (Bosch iBoost).

Thanks for the reply anyway.

Rosso1988

I need the ABS diagram ... THANK YOU ALL... MY EMAIL roberto.salatino@virgilio.it

graham c

iTrader: (5)

me too

bitterend

I ended up not using the Ford/ATE ABS unit and used a Bosch iBoost instead. No ABS though.
I still have the ECU, Master cylinder, and the wiring loom though.
I have been having a clearout and just deleted all the wiring diagram files.
I think I got them from this site anyway.