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Brake master cylinder
martin62 - 6/6/11 at 12:05 PM

Hi I am trying to improve my my brakes.I have new discs/pads/calipers up front(cortina),new shoes and cylinders at back(escort) using doner sierra m/c.The car stops but not as good as I would like.Would it be better to put a new sierra m/c 22mm in or try and get a m/c with a 19mm bore which have read on here seems to work better and if so which type of 19mm cylinder to get and where to get it.I am also going to extend the lenght of my brake pedal to try and get more leverage.Any advice or help would be great.Thanks Aidan

JAG - 6/6/11 at 12:39 PM

Hi,

Fistly - please define what you mean by

quote:

The car stops but not as good as I would like


If you want a shorter stopping distance: sticky tyres and more accurate brake balance setting - master cylinder will not change this. Sticky tyres means something like Yoko A048 or similar. Better balance is about matching brake effort more accurately to the vehicles dynamic corner weights. This can be done by changing caliper piston sizes, drum brake wheel cylinder bore sizes or pad materials based on calculation of dynamic corner weights.

If you want better pedal feel: what does better mean? Shorter pedal travel?? or less pedal effort??? The Master cylinder is the perfect place to start. Smaller diameter bore will give less pedal effort but more pedal travel and vice-versa. Changing the Pedal ratio will have the same effect.

martin62 - 6/6/11 at 12:50 PM

The pedal feels vague and firm and takes a lot of effort to stop the car just like a tin top with no servo will not stick to the ground even at low speed

Surrey Dave - 6/6/11 at 06:54 PM

Best thing I ever did was put some Mintex M1144 pads in the cortina front setup on my Locost , transfomed the brakes!


i.e I finally had some................

JAG - 7/6/11 at 12:34 PM

^^ what he said ^^

Sounds like a pedal feel issue and the easiest fix is to try some new brake pads. Master cylinder and/or pedal ratio will do it but changing pads is easier.

adithorp - 7/6/11 at 12:47 PM

A hard pedal with little feel? Sounds like the wrong ratio of master to slave cylinder. Sierra master is designed for servo assistance. Swapping to either a none servo Fiesta or Fiat master will improve things. Mintex 1144 pads will help as well.

martin62 - 7/6/11 at 05:29 PM

Thanks for the help.Thanks Aidan