Drum brake... how to reset the proportional valve?

[Gas Pig]

I’m working on a stock drum brake system all new components except the proportional valve. Initially the warning light was off in the bleeding process and I tried to great care not trip the valve but at some point I tripped it. I know there is a procedure to follow to reset the proportional valve... any of you brake gurus out there know procedure?

Thanks Jeff

 

[DirtDonk]

It's almost impossible to bleed the brakes without tripping the switch at some point.
It's not really a proportioning valve either. Just a distribution block with shuttle for the switch.

There is a tool that screws into the switch hole to hold the piston in place while bleeding. That's the best way to bleed I think. You could fab your own most likely, or stick something in the hole to hold it in place (without jamming it up of course). Maybe grinding down the tip of a bolt that screws into the hole?

But in lieu of a tool, which in a perfect world would not be necessary anyway, you're supposed to be able to just push on the brakes really hard after bleeding to re-set the shuttle.
Problem is this works like crap for most of us. As in, not at all...

If that worked as it should, the light should go out just from normal driving I would think.
There was a discussion about the tool here recently. I think you can get them from Summit.

Good luck.
Hopefully there's a better answer out there than I was able to give you.

Paul

 

[Rustytruck]

Mash the brake peddle hard and hold and if the valve isnt stuck and the lines bleed properly the valve will recenter itself . Takes a minute or two with really hard pressure held . Turn the key on,not started so you can watch the light go out. Make sure your brakes are properly adjusted to before trying to reset the switch.

 

[B RON CO]

Hi, I've fixed it by having a guy open the left rear bleeder screw, and pushing down hard on the brake pedal, and of course closing the bleeder screw when the pedal is on the floor.
Not the gentle pedal down while bleeding.
Good luck

 

[ppetersjr68]

Most of us have tried unsuccessfully to eliminate the light.
The best advice I received from this site is to remove the bulb.

Here's a link from Toms....

https://www.tomsbroncoparts.com/pag...ckprop-valve-brake-warning-switch-adjustment/

 

[Apache Bronco]

It's tricky. Whatever side the last wheel cylinder you bled, now to back to the other side. Pick a front or rear wheel cyl, have someone press on the brake pedal and watch the brake light as you slowly open the bleeder. As soon as the light goes off close the bleeder.

 

[Gas Pig]

I’m going to start in on it this Saturday. I’ll report back on my success or failure.

Thanks to all of you guys for the help!!!
Jeff

 

[Gas Pig]

No luck!

Ok I tried every suggested procedure to reset the proportional valve with out any luck. Obviously it’s stuck!

So the plan to swap it out tomorrow. I went through the my stash of proportional valves and I would say at least 1/2 of them were already tripped. I picked the cleanest one as the replacement. Then I pulled a proportional valve switch and cut the two plug end pins off. The drilled and tapped the back of it for 8/32. Then ran an 8/32 screw down into the back of it. I did this to prevent the metal switch plunger from being able to be depressed. Now I have my own proportional valve tool. Ill swap out the the valves and this time the tool while bleeding the brakes.

Thanks and I’ll report back once I’m finished!