piston stuck on stock proportioning valve?

[UGABRONCO]

I have a 76 with a stock proportioning valve and the brake warning light sensor. I know that there is a piston on the PV that slides to one side when there is an imbalance to prevent the complete lost of fluid. Is it possible for that piston to stick if it sits in that postion for a long time. Basically the bronco was driven without rear brakes and parked for about a year, and I have been trying to bleed the rear brakes and I cannot get any fluid to come out of the bleeder screw. Sorry for the long post, but I am so close to finishing the rear disk setup and driving the bronco again.

 

[iwlbcnu]

You have to pull the pin on the front of the PV to get it to reset, then bleed.

 

[HotWheels]

try replacing or removing the bleeder screws and see what you get before you get too involved.

 

[UGABRONCO]

Do you just use pliers and pull out the pin or do you have to loosen anything so that you can pull out the pin. I also removed the brake sensor and it seems to be corroded inside the PV. I am not sure if I will have to replace this or not.

 

[TOFIC]

Do you just use pliers and pull out the pin or do you have to loosen anything so that you can pull out the pin. I also removed the brake sensor and it seems to be corroded inside the PV. I am not sure if I will have to replace this or not.

Man dont sound good.
If your concerned about the valve go down to the UPick and get one out of a early Ford pickup same valve. they shouldn't cost you anything.

Then turf the one giving you grief.

TOFIC

 

[UGABRONCO]

What year range would have the same PV?

 

[TPTFPS68]

I had the exact same thing happen to me. I drove on front brakes for 6 months. I finally took the prop. assy off, put it in a vise and took it apart. the valve was indeed stuck! You have to go thru a very small inlet, but I put a small drill bit in the hole backwards and began tapping with a hammer. Nothing. I got braver and braver increasing the tapping, then all of a sudden it broke free. I had nothing to loose, except 100.00 if it wouldn't work. Cleaned it up good , the brakes bled beautifully, and still work fantastic!

 

[UGABRONCO]

Thanks. I will try your trick, but if I have any questions I will ask again. I know that you can buy a new one from JBG for 135.00, but does anyone else carry these?

 

[TPTFPS68]

I'm sure that is the going price now. I haven't looked for a while, but that's where I get most of my stuff. Good luck!