can i leave out the brake proportioning valve?

[04ctd]

Originally Posted by Illusions

Everything you wanted to know about proportioning valves but were afraid to ask:

http://www.mbmbrakeboosters.com/F.A....ng-Valves.html

there's something to be said for a guy who has a LOT of time to spend in the 'net...

thanks.

Originally Posted by gearmesh, inc.

A lot of times what most folks refer to as the proportioning valve is nothing more than a safety valve with a warning light switch in it. They don't actually control or meter pressure to either front or rear circuit.

The operation of these safety valves isn't too hard to grasp. They usually contain a spring centered spool valve with a v-notch that the switch plunger sits in when the spool is centered. Front brake pressure pushes on one end of the spool, and rear brake pressure pushes on the other end. If there are no leaks in the front or rear circuit, there will be equal pressure on both ends of the spool and it will stay centered. Introduce a leak in either the front or rear circuit, and the spool will shift due to pressure hitting only one end. The v-notch will shift with the spool shift and the warning light switch plunger gets depressed to cut your warning light on. Some spools are designed that when the spool shifts, it seals off the lower pressure circuit (the leaker). You will have a low pedal, but at least some pedal.

On older cars, these valves can get stuck due to the spool hanging up on internal corrosion debris from 20+ year old brake fluid. Some are designed to where you can unscrew an end plug and get the spool out for cleaning.

When you can't find a replacement for one beyond repair, just couple the front lines together and the rear lines together and ditch the valve altoghether. Your brakes will function just fine, but without the warning light capability.

see, that makes sense. it has a electrical connection in the center,

and has an end cap that looks like it could be the remove & clean fitting.


hhhmm

[Illusions]

Originally Posted by 04ctd

there's something to be said for a guy who has a LOT of time to spend in the 'net...

thanks.

took me longer to make the post than it did to find the info.