ABS and Brake line question for hydraulic handbrake fitting

[Antnicuk]

I have fitted a hydraulic handbrake so i can do some drifting days in the car, sacralage i know

I have plumbed the master cylinder on the h/brake (E/Brake for our friends accross the pond) inline to what i thought was the rear brake line before it goes in to the ABS unit from mthe stock m/c but it appears to be braking one back wheel and one front wheel on the other side.

On other cars i have worked on, the master cylinder has 2 lines coming out, one for the front and one for the rear. The ABS server has 4 outputs, marked VL VR HL and HR. Does anyone know what these stand for?. I have tried following the lines but its too difficult.

It looks like the master cylinder feeds a left and right hand side instead of front and rear, which will make it very difficult to plumb my hand brake in unless i pull out the abs and run a seperate brake bias which i am reluctant to do.

Also, just had another thought, i am looking to fit bigger brakes, if i dont have dedicated front and rear lines from the master cylinder, i wont be able to fit a bias valve in?

Am i right in thinking the stock bias is not done by the m/c, and is either a seperate unit (where?) or is done by the ABS unit?

Any help much appreciated.

[attack eagle]

it s normal on modern cars to have brakes on opposing corners per M/C line. This is a safety feature incase you lose one brake you don't lose that entire end of the car.
Brake biasing is done by piston sizing, ie by the choice of calipers.

[Ross]

Four circuir ABS.
The lines marked vl &vr are vorder(forward), the hl &hr are hinter(rear).
Connecting your handbrake abomination to those lines will give the result you seek. I can't speak to this modifications effects on the ABS system other it probably will be negative.

[Antnicuk]

abomination LOL, thanks for the help, the handbrake must be connected to one line, ie, before it is split to left and right. It means i would have to bypass or remove the ABS which i dont want to do as it works.

[Rus]

Perhaps consider simply removing power to the ABS module when you intend to use the car for drifting? I know on many cars pulling the ABS fuse disables the system.

[Barney Paull-Edwards]

From experience I am afraid to tell you this won`t work.Nearly all Rally cars with hydraulic handbrakes have had the lines completely re-run, with a "T" after the ABS pump. What you see Loeb pulling is actually a completely separate circuit.
Certain "official" cars, Audi A8`s that I know about have had a hydraulic slave cylinder inserted instead of an auto-adjuster which is then operated by a completely separate circuit complete with a reservoir under/in the fascia. Given a little research you may be able to do this,after machining the shoe ends to fit a very small(old mini rear) slave cylinder.
If you want your handbrake to really bite then two cheap things will help,replace the cables with Morse marine engine control cables (less stretch)and alter the leverage of the operating lever which pulls them on.
If some guru can tell you,a 4 pot(piston) calliper can easily be adapted to give 2 pistons for foot and two for handbrake, the standard opposed piston calliper is not adaptable. Oh,the B6 armoured 7 series has some system that allows the foorbrake to only operate the rears,bet they won`t tell you how! Good luck!!

[Ross]

"Oh,the B6 armoured 7 series has some system that allows the foorbrake to only operate the rears,bet they won`t tell you how! Good luck!!"

I'm thinkin' that would be peanuts with proper control to ABS. Everything goes through there, shutting down the fronts could be accomplished through the ABS. No?

[healtoeit]

Abs sucks for the track...