Brake balance valve

[phillpot]

Had a few cars in my time and even when I was younger most had front discs and drum rears but never used to have any sort of balance valves but all seemed to stop reasonably well. So my question is, is it neccessary ? would the rears be forever locking up under heavy braking (fronts do at the moment) ? Anyone tried running without it, road use track days or racing ?

[GreenV8S]

It's absolutely essential. This adjusts the brake balance to compensate for weight transfer under braking. Without this, you will have a constant front/rear brake distribution which means that there will be too much braking to the front under light braking or too much to the rear under heavy braking. The older cars you worked on would almost certainly have had one (they have been standard on production cars for decades) even though you might not have noticed or recognised it.

[Barkychoc]

The S valve is visually identical to the one on the sierra, and as all the brake parts are from a sierra I dare bet that its just a standard sierra item.

[phillpot]

Cars i was thinking off without them are decades old !
1960's Elans, MGB's TR6's etc from a time before dual circuit brakes when even servo's were an optional extra