4 Wheel Disc-Proportioning Valve??

[IN2FORD]

I am trying to figure out what to do on my brake system. I have no idea what my truck came with because some of the conversion was already done so I am not sure if my current valve is drum/drum or disc/drum. So rather than guess and hope I thought I would just pickup a new one that is disc/disc. Also looking at CPP's website, their diagram doesn't even show one only and adjustable valve in the rear brake circuit only and a "T" to split to each front brake. What are you using and where did you mount it?

Barry

[HIO Silver]

Wilwood...

'had to make my own bracket a coupla years ago. Wilwood has since come out with one of their own for around $35.

[FORDification]

The only time you need a 'proportioning valve' is when you have disc/drum. You don't need one for drum/drum or disc/disc. However, having an adjuster like the Wilwood allows you to fine-tune the front-to-rear bias, depending on the vehicle's weight distribution, tire size, etc.

[tqwrench]

You do need a proportioning valve in a 4 wheel disc system or you'll get rear brake lock up during hard braking.

You do not need a metering valve in any system that is drum/drum or disc/disc since the purpose of a metering valve is to slow the application of the disc brake calipers to allow the wheel cylinders time to overcome the spring pressure holding the shoes back in the drum setup.

The purpose of a proportioning valve is to decrease pressure to the rears after a certain point (known as the split), proportionally lowering their pressure in response to an increase in pressure on the fronts (known as the slope). This prevents rear wheel lock up during a hard braking event, since you have physics of suspension dynamics and inertia working "against" you in terms of keeping the rear wheels from skidding.

Many manufacturers will make one proportioning valve or combination valve that fit a large variety of models and manage differences within those lines with bore sizes. Example: a station wagon and a sedan will have the same proportioning valve, but the wagon has larger wheel cylinder bores that will allow more pressure on the shoes during a braking event identical to that in a sedan. The wagon almost always has more weight over the axles.

[IN2FORD]

Awesome info!! Thanks!

Barry

[Madman]

I got a disc/disc set up through Bronco Graveyard.

[convincor]

Disc/ Disc from summit
http://www.summitracing.com/parts/rsd-pvk72