hi all, i am swapping my rear sierra drums to hi spec 2 pot sva callipers.

i want to use the same master cylinder, as all ready fitted, which is a servo type cylinder out off the sierra with the servo taken off.

so to fit a brake bias valve in the rear line is it best to fit it at the front off the car or the back?

as well what one do you recommend?

i plan to take it to local mot station and fine tune the bias.

cheers

stuart

You can't set brake bias on MOT rollers --- due to weight transfer effects it can only be set up properly by careful road testing on dry roads. IVA test tries to simulate weight transfer but the validity of the results is questionable.

If you have 9" drums you already have more rear braking capcity than you will ever required short of fitting a 7 litre v8 in the car.

Brake pressure regulator valves are only ever fitted in rear brakes.

Save yourself a lot of money If you want a better feel to the brakes and more stopping for less push on the pedal simply fit a master cylinder designed to work without a servo i.e. one with a smaller bore. Subject has been covered by very many threads.

[Edited on 17/6/10 by britishtrident]

hi, i have 8 inch sierra drums. i know i do not need them, just for looks relay.

as for the position i ment in the rear brake pipe, just location.

and i got a local mot guy, how has a braking meter, and tested my brake on road when i need to check it will pass sva, so i can get a % of rear braking effort before and after

cheers


struart

Somewhere in the latest IVA regs it says that bias valves are now not allowed.

Note 4: Hydraulic valves that only operate automatically and react to vehicle loading or braking forces are permitted (Load Sensing and Gravity valves) Manually adjusted valves (other than to permit presetting the automatic function of a valve) are not permitted to be fitted even if they are rendered un-adjustable.

But, as I understand the above, a hydraulic bias valve, preset but not adjustable, is permissible, even it is adjustable for presetting. But if it's adjustable to allow it to be preset, and rendered un-adjustable, it's not allowed.

Is there a lawyer who can decipher that for us?

Cheers,
Nev.