The Stovebolt Site Forums The Shop Area Driveline Disc/drum proportioning valve

Ok here is the latest on my nightmare, I'm kind of in a hurry to get this truck drive able as I'm more than likely going to be moving (possibly out of state) so my options have just been limited as to priorities of work. The disc/disc frame mount kit isn't going to work until I get a new rearend, new tranny crossmember, new frame mount pedal assembly. So the plan now is to run the discs up front (already have the axle set up and ready to go), 3/4 ton 8 lug rear and mount the booster and M/C to the firewall. I'm tossing up the idea of just using the M/C without the booster (not sure if it'll work with the disc/drum setup) or use the booster and M/C which I'm assuming will need a new pro portioning valve since it was originally setup for disc/disc.

So my questions would be, will one of those universal, adjustable proportioning valves work? Is there a disc/drum proportioning valve that would be better? Will using the master cylinder without the booster stop my truck safely and would I need a proportioning valve to do that as well?

And yes the PO already had a master cylinder setup on the firewall, while it's not the best looking conversion I've seen it'll do ok till I can get settled. And no I can't reuse the old master cylinder because it's rusted and leaky and holds next to no fluid. So I've gotta do what I can do with my limited time and money and would appreciate any answers.

I would caution cutting corners with brake work. You can get an adjustable proportioning valve and it should work. You can probably get by without the brake booster but it will take more pedal pressure to stop the truck. Another thing you should look into is stiffening and bracing the firewall. You would be surprised how much force is put on it when pushing on the brake pedal.

I won't be cutting corners, I just don't have all the stuff available to mount it under the cab or the right rear end to hook up the discs in the rear. The PO did the firewall mount and removed all the OG brake pieces (frame assembly and pedals) it's done right I just don't like the way it looks, especially after dropping the coin for the kit I have.

What disc kit do you have?

Classic Performance if I'm not mistaken, I bought it a few years ago had stuff come up and just started tearing the truck down a few months ago.

Brothers sells prop valves for disc/drum among others for this vintage.

So Dads50 where did you mount your prop valve? I have everything figured out but where to mount that. Thinking about making a bracket to mount it below the MC. What do you think? Anyone?

So Dads50 where did you mount your prop valve? I have everything figured out but where to mount that. Thinking about making a bracket to mount it below the MC. What do you think? Anyone?

when you get old you hit the key twice. Be careful of this! LOL

The kit I used came with a bracket to mount below the M/C
...pic...

I did have to modify the prop valve bracket a bit

...pic...
The diagonal cut.
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duggan
I'm using a kit without a booster, truck stops very good
The M/C and prop valve came in a kit designed for disc drum.
You stated your rear is 8 lug, what are you running up front?

I didn't get that. Where did you get it? Thanks for all the pics!

I purchased the kit from Tucker's in las Vegas

The box it came in said P.O.L.
Performance On Line

Neither Tuckers or POL has that bracket listed. Its the perfect thing. I will make a few phone calls tomorrow. Also, did that bracket come with the short lines or did you have that done somewhere else?

it came assembled

...link...

just have to plumb to the prop valve

Brothers is really a decent place to get certain things. VERY helpful and nothing is a problem for them. I made the mistake of ordering the prop valve without the bracket, but they had the bracket had I asked for it. I just called them and they are shipping me the bracket and the short tubing needed to connect to the MC. I will duplicate the steel tubes with stainless once I figure out the tool I need to do that. Thanks again!

I used a Wilwood adjustable proportioning valve with my disc / drum setup. Mounted on firewall below the booster assembly.
Approx. $ 70.00 as I recall.