Brake master cylinder sizes

[stephen wilson]

A prop. valve to the Front sounds like a very bad idea. What if you have some brake issues and need to really press on the pedal, you won't have any extra line pressure available. The "proper" way is with a balance bar(dual masters), or replumb the system without the ABS, with a prop. valve on the REAR brakes. You could also try mixing brake pad compounds front-to-rear.

[bam914]

Thanks for the info. Rebuilding the calipers this weekend so I will take the ABS unit out at the same time.

The front brakes already have a prop valve in them. See part #6. It is in the front brake line before the ABS pump.

[stephen wilson]

From that diagram you can't tell if it's in the F or R brake line. That's irrelevant though, since it's used in conjunction with the ABS system, once you remove the ABS from the equation, it's a whole different ball game.

I've never heard of reducing front brake pressure ( via a prop. valve) to adjust brake balance. You always want full pressure to the front, and control balance by reducing rear line pressure. To adjust overall brake effort, you can reduce or eliminate boost, change master or caliper piston sizes, or change the mechanical pedal ratio.

[bam914]

"A" is the front brake line.

I will see what happens.

[stephen wilson]

That makes sense, and places the factory prop valve in the rear (B) line. You could just replace the factory one with an adjustable unit.

[bam914]

The diagram is wrong. The prop valve is on the rear. The next page it tells where each one goes on the ABS unit.

[LAP1DOUG]

Originally Posted by bam914

The diagram is wrong. The prop valve is on the rear. The next page it tells where each one goes on the ABS unit.

Great find - thanks for sharing. Please let us know how things work out if you replace with an adjustable prop valve.