If you got the rear disc kit from Stanless Steel and they do offer adjustable proportioning valve to replace your stock valve. You can adjust 60/40, 50/50 or 70/30 breaking from front to rear. I know this, because I have 4 wheel disc on my Jeep.

Nycjeep

 

Is it possible to get that seprately or is it part of the kit? Do you need to run a different proportioning valve if you switch to disk brakes? Or can you fudge it? If I do fudge it, what should I look for that a different valve will help offset? Thanks for the ideas.

Florida Mud CJ-5
'77 RB304, t-150 D20 4" 35" swampers

 

New Proportioning valve does not come with the kit, its optional. It depends on what you are towing and how much load you are hauling. With this valve you can select more pressure to front or back (you can always call Stanless Steel for more info).

Nycjeep

 

So bouncing down the road (literally) with my 35" tires the stock proportioning valve will get things slowed down without any quirks? I'm putting a home-brew rear disk on my '77 5, and hadn't even thought of getting anything different than what I had... would there be any advantage to changing it, keeping in mind I rarely have more than 2 ppl in the jeep?
thanks

Florida Mud CJ-5
'77 RB304, t-150 D20 4" 35" swampers

 

While I haven't got any definitive answers, here is what I've gleaned from www.mp brakes.com (remove the space in the url)

When running 4wh disc, the proportioning valve does not have the residual valve or the metering valve. disc/drum prop valves have a residual valve at 10 lbs for the rear drums. The metering valve introduces a delay to the front discs since the drums respond slower...

mpbrakes sells a prop valve for disc/disc for 109.95, but it looks identical to mine and it looks like I could disassemble it...so I am going to check it out before laying down any $$$ on this...

Jim O'Brien
rkcrawl@tidesys.com
My jeep page