brake proportioning valve= no reset?

[Sport/Truck]

I tried to bleed the brakes and don't think my portioning valve is working correctly and I don't see the reset button/pin? Here's a picture of what I've got. How can I reset this?
s/t

[Sport/Truck]

Is it possible to take this apart to clean/reset?
s/t

[truckdude239]

to reset mine i just stomped on the brakes

[Sport/Truck]

To be honest, I'm not sure how this happened.
I bought a new master cylinder and now I'm trying to get everything bled.
s/t

[americanmusc1e]

the reset button is on the front, it may be under a rubber cover

here's my disc brake swap thread, it may help, look near the end
http://67-72chevytrucks.com/vboard/s....php?p=3171895

I now bleed my brakes by forcing fluid up from the bleeder to the master cylinder (jack the front end up until the master cylinder is level or you may have problems) starting with the longest line and working up to the shortest line.

You can do this with the porportioning valve stuck and then after you get all the air out, close the bleeders and work the brakes, the porportioning valve should unstick itself

[Sport/Truck]

I don't think I have one on mine, do I? It looks like it's just a large nut with a provision for the rubber boot - minus the plunger.
s/t

[68shortfleet]

Or you could use an electrical test light to verify if the valve is offcenter. When the valve is offset, the wire terminal on top is a ground to the body of the valve.

Jason

[truckdude239]

thats why i always gravity bleed mine before i pump them up

[gator2511]

Comparing it to mine on my 72 you are missing the boot and plunger. My shop manual says the plunger must be held in for the brakes to bleed properly. I made a little tool for this that has a long slot that slips under the front mounting bolt and runs along the valve and turns a 90 degree angle to cover the piston on the front of the valve. I back off on the front valve mounting bolt, slip the slotted end of the tool under it and snug the bolt. Then I tap the 90 degree end to push the valve in and then I tighten the bolt. The brakes bleed easy after that. Just remove it when you are done. Without the boot and plunger I don't know what to tell you.

[jaros44sr]

Originally Posted by gator2511

Comparing it to mine on my 72 you are missing the boot and plunger. My shop manual says the plunger must be held in for the brakes to bleed properly. I made a little tool for this that has a long slot that slips under the front mounting bolt and runs along the valve and turns a 90 degree angle to cover the piston on the front of the valve. I back off on the front valve mounting bolt, slip the slotted end of the tool under it and snug the bolt. Then I tap the 90 degree end to push the valve in and then I tighten the bolt. The brakes bleed easy after that. Just remove it when you are done. Without the boot and plunger I don't know what to tell you.

Got pics. of the tool, sounds clever. I think I understand, but would like to build one, as I'm in the same boat

S/T, if you need that part, LMK

[Sport/Truck]

Originally Posted by jaros44sr

Got pics. of the tool, sounds clever. I think I understand, but would like to build one, as I'm in the same boat

S/T, if you need that part, LMK

I may take you up on that.
But here's what I'm going to try.....do you think this will work?
I used a ohm meter on the warning light switch, it reads continuity, no fluid to the rear so, I'm going to tap the front on the anvil to cause the piston to shift forward until it's reading no continuity.
Think this will work?
s/t

[jaros44sr]

Originally Posted by Sport/Truck

I may take you up on that.
But here's what I'm going to try.....do you think this will work?
I used a ohm meter on the warning light switch, it reads continuity, no fluid to the rear so, I'm going to tap the front on the anvil to cause the piston to shift forward until it's reading no continuity.
Think this will work?
s/t

Maybe, anything is possible...but if you mess something up, I have a complete prop. valve that was working before I bought a new one. Keep us posted on your progress. Got 2 good tips so far

I could be wrong, but isn't the reset on the front of the prop. valve

[mbgmike]

Here is a pic of a tool they sell.

[Sport/Truck]

I got it reset! I removed the switch and you can see the valve body inside. I turned in on end and taped it against the anvil it was real easy to move into place.
Thanks for all the help.
s/t

[jaros44sr]

Originally Posted by mbgmike

Here is a pic of a tool they sell.

Thank you

[66_k10_manny]

I just installed front disc brakes complete with mc and booster on my 66 k10. Kept the rear drum. I installed a new proportioning valve complete with new lines and bled the system. My front brakes grab great but the rear brakes are locking up real easily. My pedal also feels kind of spongy. Do you think I might have a similar problem with air in the system or having to reset my proportioning valve?

[robs71k5]

OK I see this post is quit old but was just wondering how hard one had to hit the. Little anvil to reset the proportioning valve. I seem to have gotten my brakes back when I hit it but there is still continuity and the brakes improved immensely but could they be better? I'd like to think so!. And when you stomped on the brake where the bleeder screws open or closed ? I may have to keep at the reset untill continuity goes away?

[Ironangel]

Stomp the brakes with the bleeders closed. The OP's prop valve didn't have the indicator pin that usually protrudes when a rear wheel cylinder fails. If yours is protruding, push it back in and hold it with the tool. Then bleed the system starting with the RR, LR, FR, FL, and you should get a firm pedal with no light once the tool is removed. If you have a firm pedal and the light stays on, then give it a stomp to reset the prop valve. It's not unusual for a 45 year old system to get rust and dirt in those valves causing them to hang up. They are not rebuild-able but like the OP did, you can open the electrical switch and possibly relieve enough pressure that it will slide back to center thus opening the light circuit allowing the light to go out.