which brake master cylinders?
Turbo Mini Forums

Hi everyone,

I'm updating the brakes on my second car at the minute using all (potentially) my mini stuff (mini is getting other running gear :$ ) .
The brakes will be 7.9" vented 4 pot fronts and standard rear with a bias valve to control rear pressure if I need one, not sure if I get the right spec master cylinders in the pedal box?
I want to remove the servo for bulkhead space and fit a internal pedal box, im not sure what master cylinder sizes to run though!
Could someone help please, Obvioulsy I want a quality that is safe but im not overly fussed about picking the expensive brands if someone could advise cheaper alternatives and what ratios I need.

I know my polo is .75 and 1" but really not sure on the mini!


Any help greatly appreciated,
Ben

Edited by MINIMON on 20th Jun, 2013.

Anyone any advice, need this all done asap so ordering as much as I can for my week off next week.

Sorry ive changed my search criteria and discovered the very answer I need! Or so I thought....

The standard master cylinder has front and rear lines in 1 cylinder, now i'd like to stick to 1 aftermarket cylinder. My questions are: how would I go about retaining 1 cylinder?
Would i have to add the front and rear sizes together and then buy a cylinder that size?
Do i just go off the .75 recommended size for the fronts and fit a pressure valve for the backs to reduce the pressure to them? Does that even work out correctly? Ive really no idea!

My plan is to get more space in the engine bay for the boost pipes basically and to minimalise the engine bay as much as possible.
Due to the angle of the kick board ive decided to retain the stock pedal box (also not wanting to alter seat position from stock) but change for a smaller master cylinder with NO servo.

I had this very same thought when doing my conversion. I know some people use a 1" AP Racing master cylinder and a 4 way tee piece (2 to the fronts and 1 off to the rear plus 1 input). But im not sure how this affects your MOT because your car was not originally made which a single circuit brake system. Ive since purchased a KAD pedal box which mounts into the engine bay. Its a really nice piece of kit (although i havent yet used it). You can then keep your split circuits to keep mr MOT man happy and also run different master cylinders. I run a .75 front and .625 rear (although not tried and tested). Ive fitted an in car cable adjuster so i can play around with brake balances.

Hope this helps!

Ahh really, so 1" master cylinder is good enough? that makes it roughly a .75 front (as recommended) but only .25 rear? Or am I getting that all wrong?

My MOT man is preety happy tbf so long as its not pikey, My turbo is mounted over the gearbox too so sorting it again with a new down pipe and manifold isent something I want to do, ideally haha. Small cock up by me really, I should of planned brakes before dry building the engine bay.....

Anyone able to assist as to what master cylinder I need If using a 4 way split, Is it right to use a 1" item then split it on the rear line with a bias valve?

A 0.75" front and 0.625" have a combined volume of aroung 95% of a single 1" as the volume is proportional to the diameter squared. So you would think that if a 0.75 front and 0.625 rear are alright, then a single 1" would do the job, but i'm not sure and I would wait for someone with experiance to comment.

WOW.... Mind, now f**cked.... hahah.

I see your logic mate, im not bright enough to work that out so just hoping someone can confirm for me.
Thanks!