Proportioning valve questions..

[EagertoLearn]

I know the top two holes are where the brake lines run up to the master cylinder. Is the opening in the back of the proportioning valve where the lines runs to the rear brake lines block the rear end? There also is a port in the front is this where the line for the front brakes start? Also where does it go from that port to where? The final port is towards the front of the proportioning valve but on the bottom side. My original one seems like it has a plug in it, is that correct? The next picture is the rubber brake line which has a block on the end. Where does this mount and how does the line from the proportioning valve attach at?

 

[DirtDonk]

My rear hose is different. That one looks like the front axle hose. Does the loose end have only the one large hole (for a bolt) and the one threaded port? If so, I think that mounts to the frame near the proportioning valve and goes down to the front axle.

The rear would have the block same as you have mounted to the axle, but would have a hex-shaped fitting on the end with only a single threaded opening for the steel line and a groove for the retaining clip. Probably also has a smaller groove with an already-installed retaining clip to keep it from pulling through, but some simply have a larger flange formed into it for the same purpose.

Otherwise, the one you have needs to be bolted to the side of the frame, which is not correct for any Broncos that I've worked on. You should have an angled bracket with a hex hole in it welded to the junction between the crossmember and the frame rail on the driver's side just in front of the gas tank.

That sound right?

Paul

 

[DirtDonk]

For the prop valve, I'm not sure what goes where, but on a stock one there is a larger port for an electrical switch that works with the brake warn light on the dash, and also a push/pull button valve thingy for use only during bleeding.
There is only a single line to the front brakes and a single line to the rear.
I've seen prop valves that had one extra port that was capped off. Evidently the same valve was used with vehicles where two lines were used for the front brakes, but Broncos only use one.

Whichever ones you use (and I'm sure someone will pop in with the correct port orientation), one hard line will go from the proportioning valve to the block on the end of your front brake hose. There should be a hole where you can bolt that block to the frame nearby. Hopefully someone will post up a pic of where theirs are mounted.
For the rear, you will have a single hard line running back along the driver's side frame rail to a point near the rear crossmember meets and the rear hose mounts. As I described in the previous post.

Good luck. Hopefully someone has pics for you.

Paul

 

[JIMS74]

Hope these help.
Jim

 

[BoltBuster]

Eagertolearn,

There are 3 internal types of that same valve body(GM) drum-drum, disc-drum and disc-disc.

2 ports on top for the lines from the master cylinder to the valve, Front Brake IN (TOP FRONT) Rear Brake IN (TOP REAR)

1 right front port(bottom front), 1 left front port(45deg front) and 1 port to rear brake line(rear). As an option you can use either port for the front brake 1 line system, just plug off the other.

There is no adjustment on this valve. It is set to be 70% front brake, 30% rear brake pressure.

I added a 10lb residule inline valve for the rear from Summit to prevent premature pressure in the rear brake cyclinders and causing lock up at even low speeds.

I also swapped my old Master cyclinder that was resvoired for Drum-drum brakes from a 76 F250 Camper Special.

Rubber line, depending on your lift? (length of hose) If you have more travel than hose well you know where that is going to lead. One end is usally mounted to the front axle the other on the frame. The Front axle brakes are attached to either or both FRONT 45deg or Bottom FRONT holes. Since your using a shared line system on your front axle you will need to cap off one of the two on the proportional valve FRONT holes and run a line down to the rubber/brass connector.

 

[EagertoLearn]

Thanks Guys, this is exactly what I needed. I can finish running my brake lines and get started on the fiberglass tub on Monday.