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posted on 7th Jul 17 at 14:01

A proper set up should be as follows:

0.625" master to the front
0.750" to the rear

Pedal ratio is normally 5.5:1 or 6:1
(yours appears to currently be closer to 9:1 !!!)

Set up the balance bar so that it is level (90 deg to the push rod) when the brakes are applied fully. To do this you will need to shorten the push rod going into the rear (0.750") master cylinder. This step is very important to give you a good pedal feel and is the most likely step to be ignored.

Next put the bias all the way to the front, go out and stand on the brakes as hard as you can. You will find that the front should lock very easily. Wind the bias towards the rear and test again. Keep going until the rear brakes dig in and keep the vehicle braking in a straight line. Do this with nice warm brakes in the dry.

*If you are using it hard in the wet, the bias will need to go to the front more to stop the rears from locking first.*


posted on 2nd Jul 17 at 19:18

finally got round to testing it today. Front brakes stuck on again but managed to free after putting in a bit more play on the master cylinder
So I have a bit more breaking performance but pedal feels a bit soft.


posted on 29th Jun 17 at 13:47

0.625 front with hi spec 4 pot calipers. 0.75 rear stock shoes

Haven't had a chance to test new pedal

[Edited on 29-06-2017 by Stu_22]


posted on 29th Jun 17 at 11:41

what size master cylinders are you using front and rear on your pedal box?

I've got the same setup, but with Reyland (AP) calipers front and rear discs with the revised pivot point and its also has rubbish feel


posted on 26th Jun 17 at 18:58

Standard left new pivot hole right


posted on 26th Jun 17 at 18:58

Thanks hope it looks like this


posted on 26th Jun 17 at 11:18

Sorry mate... Just seen this. I'll get you pictures this week when I'm in the garage. :thumbs:


posted on 21st Jun 17 at 21:36

So here is my brake pedal

Not much room to move the hole up


posted on 21st Jun 17 at 09:08

Found this

Just got to hope it hasn't been done already


posted on 20th Jun 17 at 19:07

col please could you get me a pic of this mod. I bought the pedal box already attached to a pedal so not sure if its been done


posted on 20th Jun 17 at 18:32

I have one... I've not drove it yet as I'm far too lazy to finish the car :lol:

I have modded the pedal arm as stated above. The reason I've gone down this route is because I have driven one (with the pedal arm mod) and it felt great with a good calliper setup. :thumbs:

[Edited on 20-06-2017 by Col004]


posted on 20th Jun 17 at 11:54

sounds like driving my old mini


posted on 20th Jun 17 at 07:47

you need to redrill the pivot point where the bias box connects to the pedal.

to increase the ratio so you get more leverage from when you press the pedal, giving a softer pedal.

had the same issue


posted on 15th Jun 17 at 15:38

I had a set up simular to this I hated it.. I had ap front brakes rear disc conversion and it felt like the car didn't wanna stop.. pedal was hard as fuck


posted on 14th Jun 17 at 09:27

Anyone here that still has a corsa or had a corsa with the brake bias box instead of brake servo?

I have replaced the servo assisted brake master cylinder on mine with the twin cylinder bias box but so far not impressed. the pedal feels solid and the calipers and Pads(hi-spec green stuff) were good on old servo set up. Now it takes a lot of effort just to get the car to slow let alone be at any point for the car to lock its brakes. I have tried adjusting it more to the front but that resulted in the brakes locking up.

Any suggestions