I have finally got to the stage where I am considering brakes/pedals etc. True to the locost spirit, I would like to use the master cylinder from the donor Fiesta (I'm building a Midi) but I don't want (haven't got space) for the servo. The Chris Gibbs book implies that this can be done -can anyone give me an idiot guide on how - is it really just a case of remove servo, make new rod?

Sorry if this is a dumb question!

JC

Yep!

[IE, that is how you do it, not a dumb question]

Oh Blimey, now I'm confusing myself

[Edited on 12/3/08 by robinj66]

That's basically it - just make a new rod to suit your pedal setup.

You need the brake master cylinder and push rod from a non-servoed car.

The reason for this is apart from the difficulties with the push rod arangement the master cylinder on servo equiped cars is a much bigger diameter than no-servo cars. Without if you don't fit a smaller diameter master cylinder the pedal effort required to the car will be excessive.

Why not look at the brake and clutch pedal arangements on Minis and Metros/Rover 100s.

But, depends on the weight of you car, if it's half weight of the fiesta, and you have used the whole break system... If we take the servo to be providing half the breaking force then without the servo and half the car weight, you end up with the same breaking efficiency (so long as you keep the peddle ratio the same).

Dan

quote:

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You need the brake master cylinder and push rod from a non-servoed car.

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Are we saying that using a servo on a 7 would make the brakes lock up under light braking or would you teach yourself to brake differently like when swapping from one car to another?

I have a servo that fits ok with a small dual circuit master on mine, but have had that now 4 years (still in build process) and wondering now if i should ditch the servo or live with what i have.

Also will the Crossflow produce enough vacuum for the servo??

You would almost definitely teach yourself to brake differently whichever setup you choose. A servo will make things a little over sensitive imo but on the other hand braking for the first time without a servo can be an exciting experience.

It is all down to piston sizes and pedal ratios - get them right for your individual setup and everything will be fine.
Personally I prefer not to have a servo because it is an unneccessary complication on such a light car, much like power steering.

I took out my servo on my sierra based system and used the original master cylinder, cortina M16 calipers and capri drums at the rear - I cannot image a better system for feel and efficiency, totally perfect.