Brake proportioning valve
- Thread starter Scott79
- Start date
'68 does not have a proportioning valve, they use a brake warning valve. Among others www.inlinetube.com has them some of the time, if not try a google search for '68 mopar brake warning valve.
Dave
Last edited:
Proportioning valves were usually on disc/drum systems. OEM-production proportioning valves are around and in repro.
The master cyl bore diameter and the wheel cyl bore diameter, plus the different brake shoe widths were how the drum brake systems were "proportioned" f/r, usually.
Adjustable proportioning valves can be found in the Mopar Performance catalog, usually, and the similar Ford and Chevy Performance Parts catalogs, too. Probably other places too.
Happy Holidays,
CBODY67
The master cyl bore diameter and the wheel cyl bore diameter, plus the different brake shoe widths were how the drum brake systems were "proportioned" f/r, usually.
Adjustable proportioning valves can be found in the Mopar Performance catalog, usually, and the similar Ford and Chevy Performance Parts catalogs, too. Probably other places too.
Happy Holidays,
CBODY67
That's a distribution block/safety switch and not a proportioning valve.
All it does is if you lose pressure on front or rear brakes, the pressure in the working side pushes a small piston up far enough to turn on a warning light. That, and provide a good place to split left to right, is all it does.
I suppose it could be gummed up and/or the piston could be stuck.
A cross section. I've never had one apart, but it looks like it could be taken apart easily. Also really not all that crazy expensive to replace.
A good run down of proportioning valves here:
68plymouth383
Senior Member
I have a good used one. Jasons85dodgeram@hotmail.com
Interesting...I always thought they were proportioning valves.. learn something every day! Just like newer ford oil pressure gauges are just off/on, they don't represent actual oil pressure!
The early brake fluid loss divider blocks can tend to look similar to the 1970+ GM proportioning valves which also have that fluid loss switch in them. But if it's a drum/drum system, the only thing there is to divide the f/r fluid and turn on the warning light when one end of the car looses brake pressure. No more, no less.
GM terms their proportioning valves that also have the fluid loss sensor in them as "Combination Valve". On disc/drum vehicles.
Happy Holidays!
CBODY67
GM terms their proportioning valves that also have the fluid loss sensor in them as "Combination Valve". On disc/drum vehicles.
Happy Holidays!
CBODY67
Someone probably did, but that doesn't mean that you need to do it. Always done with good intention to help, we all occasionally give bad advice.
I've done a couple dual cylinder upgrades and never had any problems. I've used OE distribution/warning light blocks from later cars and an aftermarket blocks too.
tbm3fan
Old Man with a Hat
Upgrading my single pot master in the F100 to a dual master plus a power booster. Everybody asks about a proportioning valve but in a Ford it is a distribution valve with the brake warning light when four wheel drums. Now in my upgrade, since it is damn near impossible to find a decent distribution valve I will be using a proportioning valve under the master which came in an assembly kit. So I can adjust the pressure down in the rear since more braking effort comes from the front anyway.
3175375
Senior Member
Link, please. That setup looks great!
tbm3fan
Old Man with a Hat
Got off ebay after a fellow F100 forum member showed it to me. Saved it to my list and the next day the seller emailed me a new price at $81.62. Right now it is awaiting installation as I am dealing with the rod between my master and power booster being too short despite adjusting. So that comes first.
Yes, I saw GM and ignored it since the person who referred it was reliable.
GM Disc/ Drum Brake Proportioning Valve Distribution Block Kit + Bracket & Line | eBay
Charlie's 66 Fury
New Member
I'm a recent owner of a 66 Plymouth Fury that came with front disc and rear drum brakes with a SSBC proportioning valve (see attached pic). Since I am replacing the brake lines and all brake parts, I was curious if I should replace the proportioning valve. I have no clue if it works since I took the car out of commission a couple of days after buying it. Aside from leaving it installed and once I have everything connected, test it while making test runs with car, anyone have a suggestion as to how to test these on a bench? Blow thru it? 
Should I replace it and with what?
Should I replace it and with what?Similar threads
