This is THE BEST explanation of this component and how to reset it I've found on KZfaq. Thank you!

Great information I was starting to cuss after replacing the master cylinder this got me back on the road in minutes .. thanks

I have the same style proportioning valve in my 1972 pontiac catalina. I'm about to replace all the brake components, so knowing this will help in getting the system functional.

Thanks for the video , I installed rear disc on back changed porpotioning valve also.

Thanks man I have a 87 k5 and had the same problem replaced the master cylinder lines and the whole brake assembly on front and back tried this and its a good a hold now! Thanks, and subscribed.

To reset with the side buttons, remove the rubber cap. Grab a 3-in nail between some small vice grips and push in on the center or try the Allen wrench like he showed. Mine only moved an eighth of an inch and I didn't think it did anything but it was enough. The light was off. You'll know when you're brake light turns off and the key is on for a minute. Back brakes bled fine after. Push from the front to release the back push from the back to release the front.

Great vid, I have an old distribution block from 1969, no matter what I do front disc brakes have air. Rear's no air! I can't access the switch itself to look in and see if "it's moved" or not, yet alone even remove it. I removed front STEEL brake line(drivers side) and pushed the rod inside 1mm or so, presumably towards "rear brake section". Do you think that is enough, I know it's a guess? I'm going to re-attach hard line, vacuum bleed to start fluid moving (prevent switch moving by doing that) then gravity bleed. Any other tips? FYI I replaced all calipers and cylinders, rubber lines and not a single fluid loss, air is getting in somewhere. all fittings tight. at a loss. thanks again.

@Kyle Owens. Hi Kyle, cool video by the way. You kept saying the rear brakes were blocked off. How did you block them off... By disconnecting the main line & plug it? My daughters husband had their car towed home because the brakes went out. My concern is that he got it into his head to keep pumping the brakes on the vehicle, (1996 Pontiac Grand AM), But not checking an ''Almost Empty'' Brake Fluid Reservoir..... Thanks & again, great video buddy......

Great video !

I got a 83 k20 scottsdale and just replaced drums and brake lines I have brake fluid coming out of the rear and fronts I have a solid petal until I start the truck once it’s running I have no pedal at all do you think this is a similar issue or another issue? A brake line cracked but before that brakes worked fine

Hey bro my brake pedal on my c10 is stuck it won’t go down, happened while bleeding brakes and front caliper replacement…. Any idea what it could be???

I have a 98 Tahoe 5.7 engine with police package break system, can’t find my proportioning valve any help?

Hi Kyle, thank you for this video. My 93 S10 is in the situation since I changed the front brake hoses/calipers/discs. Now it won't bleed. If I now open the rear brakes and apply pressure, why won't the valve just go all the way over to the other side and block off the rear lines at that point? Why would the valve reset? Seems like I would solve one problem, and create a new one? What am I missing? Thank you!

C10 1986 rear brake line broke.. The shop fixed it and bleed the brakes.. but the light still on..They told me to replace the whole valve. Not sure

Appreciate this video

My front brake line broke, and the switch did not kick over and block the fluid from shooting out. The vehicle is a '92 Dodge truck and the valve is no longer available. GM PV2 is supposed to work but has anybody tried it on a Dodge? I feel sure it would work, but only if the fittings and electrical connector would mate up to the lines and wire.

Does a 2002 tahoe have this i have replace booster,master cylinder and front break lines cause one got snapped when I got hit now im not getting fluid coming out when I bleed rear passenger

I have a similar problem with a G20 van. I changed the axles so the system was open for several days. After assembly I bled the rear and the pressure was good. Then bled the front and the pressure also was good. But the pedal was way to soft because there was still air in the system. So i bled everything again. I didn't notice that the reservoir went empty. I refilled it and started over again, the rear pressure was ok at first but then I noticed I had a small leak in the rear break line which I fixed afterwards. So I think it also could be a stuck propotioning valve, but I'm not sure. I went to a shop and they tried to bleed everything again but the rear has nearly no pressure at all. The front pressure is good. I'll have to try to pump and open the front several times like you said. Thanks for the video btw. I have another used valve here, so in the worst case I could change it. Is it possible that the problem is the master cylinder because the reservoire was empty?

Can this cause the brakes to absolutely suck ass if it’s going bad? I have a 1985 bronco and I’ve replaced everything to do with the brakes except for the proportioning valve and tonight my brakes wouldn’t stop when I was in reverse

I wonder if this would work for my Honda civic

I've heard there's a special tool of some sort that you put on the proportioning valve to keep it from locking out the brakes when you bleed the system. I I'll probably have this issue with my 85 C30 when I rip the drums off to replace the wheel cylinders as well as bypass the hight sensing proportioning valve on the rear for the back brakes. Hopefully I won't have to bench bleed the master cylinder because the reservoir for the back brakes is bone dry because the rear brakes loose so much fluid.

Please help i work on vehicles alot I've done it all. I've learned on my own plus the you tube and watching real mechanics. I tell everyone if i can't fix it or don't know how i will find a way whether it be they you tube or just asking but i have a94 dodge dakota 3.9. All 4 brakes bleed nicely the way they should yet i still am getting close to zero breakage meaning i push to the floor and it stops very slowly i basically can't drive it. I do have drums in the back disks in the front this was done before i bought it but I've replaced front brakes twice over the course of 3 years or maybe nore that i have had it now all of a sudden somethings not working right and then I've heard about this proportioning valve and differential switch etc. Well crazy part is i raised there is brake fluid leaking out of that brake switch which i have red is not supposed to Happen unless there are bad steals somewhere can someone please help i feel completely lost bad part is both my vehicles screwed up at same time. Can you help????? Thank you in advance

My rear brakes are dragging..im wondering if this may be the problem I put New everything and I mean everything 🤔 I have fluid coming out the back..Here is the crazy part while setting up the rear adjustment the drum turns just fine but as soon as I tighten the wheel it won't turn at all🤷‍♂️

have a 88 Full Size Jimmy...Replaced front to back with all New Brake parts including Brake Booster and 2 Master Cylinders and when i start my Rig Up the Pedal Goes Right down to the Floor?? i have Great Vacuum pulling from Engine all is good and i must have bleed system like 6 times already? so whats the culprit here? any takers !!

So I've got a 2000 Chevy Silverado 1500 2 wheel drive and I hit the brakes the brakes locked up on the front passenger side... I was able to go away until it heated all the way up bright red and I couldn't move anymore I did the same thing until I got home... I bought all new brake pads, rotor and caliper with everything! I took off the old one and the piston in the caliber was cracked in half probably from getting so hot as I drove it home I mean the rotor was literally glowing bright orange and red... but anyway I put everything new on and when we push the brakes for the first time it locked up immediately this time it won't move at all because they're new brake pads the old ones were old and trashy so it couldn't lock so hard but now it won't move at all! Does anybody know what would cause this? I didn't hit anything to BEND a line or anything it happened in the middle of a 6 lane highway when I hit the brakes... I think I remember that same brake smoking all over a few weeks ago for a few min then it was fine. well... they were fine until they locked up a few weeks later anyway... I did have the pedal get loose and hard in that time between... where i would hit the brakes the pedal would be hard and work but then loose pressure and go almost to the floor... ANY HELP WOULD BE APPRECIATED!!

The cap that is on the top of the brake sensor. How does it come off? Do you just pull it off or does it unscrew?

In your video, you say you open the bleeders......Are you opening both front bleeder screws?

On the left end of your valve body I see a black rubber cap. I have the same cap, & under it is what looks like a tire valve. I'm so tempted to push it. Anyone know anything about it? Will it re-center the safety switch?

So my mechanic wants me to buy a new valve but they all look completely different to the one here on the video they are yellow and look different. are they the same thing??

So I’ve bled the brakes many times I’m having trouble w my rear brakes everything back there is new drum kit, shoes, lines, flexible line the cylinder and drum. My rear brakes aren’t engaging when I press on the brake but I do get fluid out of them and my emergency brakes work can anyone help me out

Holy shit..Thank you for this! My fucking brain hurts tying to sort this out

Hi there, I changed the valve and still get this issue: the rear brakes stop before causing the the wheels to slide, mainly the rear right one. Any idea?

Once you do that how do you know it's reset? Does the "brake light" on the dash go out and once that happens you bleed them normally?

If the back brakes are blocked off open front bleeder and slam breaks and it will shift forward lke there is a leak in the front. I have done this a bunch as i was shipped the wrong combination valve and had to reset it a bunch before i figured it out.

I think this may be my problem.. I have a 77 Chevy c10 and we’ve bought a couple master cylinders and didn’t fix the problem. The front brakes bleed fine but the rear brakes barely get any fluid from the master cylinder. We’ve blown out the lines going to the rear brakes and they’re clear. Maybe this could be why the fluid is barely dripping out and we can’t bleed the brakes..

Could I use this method for a 95 Honda cvic?

So basically you started bleeding your front brakes first then the rears?

Would that work for drum brakes

If that is how that valve works, wouldn't it trip every time you bleed your brakes?

Will the proportional valve resets automatically after bleeding all of my brakes?

So how exactly do you reset the proportioning valve? Just bleed the brakes? But isn't that what causes the valve to need resetting in the first place? What is the rubber covered button do we need to press that to reset the valve? Do we need to bleed the valve after bleeding the brakes do we need to bleed the valve at all? My right front caliper is sticking and thinking it was the caliper I replaced the caliper with a remanufactured unit and it still sticks. There is no issue with the drivers side.

This makes sense but not in the manner you accomplished it .. you essentially just bled the fronts ,you didn't introduce a "leak" so how did the shuttle valve move ?im in the same predicament but I feel i need to introduce air aka a leak to get the valve to move. Am I correct in my thinking

there is a button you push in. On left side under rubber cap a pin poos out .

You didn't show how to reset the valve... Why?

simulate front brake failure to reset valve...why does it get stuck? poor design, bad quality fluid?....also im so over mixed brake systems...4 disc plz

Your proportioning valve is contaminated with rubber debris. It needs to be rebuilt or replaced because the shuttle valve is hanging up.

Great video, but you never actually say how to reset the proportioning valve!

I didn`t find this helpful at all, more confusing that anything, my `80 G10 has no front or rear brakes after doing a m/c kit, did a bench bled its fine, pumps from the m/c if i crack the pipes there, but no fluid reaches the calipers, pedal has come up ok , but still no brakes, you say `proportioning valve reset`, but you `bleed` your brakes and fluid comes out. how do you reset p/v if no fluid reached the brakes.

Do not need to pull off master if you run dry

Don't use copper line if that is what I saw.

My son cut the lines Now I need a new one plus that switch. Oh help

There is a lot of info but no video on how to reset the valve ? How come you didn't show that part?

I'm reading here in my 1977 service manual and it says: "WARNING: NEVER USE COPPER TUBING BECAUSE COPPER IS SUBJECT TO FATIGUE CRACKING AND CORROSION WHICH COULD RESULT IN BRAKE FAILURE" trying to figure out how to reset this valve and saw that. Figured that I'd share it with you, noticed that you had copper lines.

If you take an oil can and pump brake fluid backwards through the system with the master cylinder cover off. you won’t trip that valve and can bleed them normally. I dont know of anyone who has had good luck with the little plastic tool.

I did exactly the same,no dice

Next time put a 10”-14” clear hose on you bleeder valve, loop it upwards to keep the fluid but still allow air to escape.

not a thourogh job at expaining..

Unclear. Unsafe.