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Proportioning Valve Bleed Pin

Bronco_46256

Sr. Member
Joined
Oct 12, 2003
Messages
428
Loc.
Elkhart
Background:
'76, Disk/Drum
New Master cylinder
Rebuilt Calipers
New Wheel Cylinders
New Rear Brakes Lines
Fresh Fluid
Great Pedal and front brakes
No fluid to the back brakes
Front (Rear Brake) reservoir releases pressure back into the reservoir when pedal is released

I've seen a few previous posts above pulling the small pin on the front of the proportioning valve during the bleeding process.

Am I correct in the understanding pulling the pin affects the fronts only?

Reason for asking is that I have no fluid to the rear at all and was *hoping* not to have to buy a new proportioning valve.

It's getting pulled tonite either way.

Thanks
bronco_46256
 
Last edited:

72Sport

Bronco Guru
Joined
Jul 8, 2002
Messages
2,954
Bronco_46256 said:
Background:
'76, Disk/Drum
New Master cylinder
Rebuilt Calipers
New Wheel Cylinders
New Rear Brakes Lines
Fresh Fluid
Great Pedal and front brakes
No fluid to the back brakes
Front (Rear Brake) reservoir releases pressure back into the reservoir when pedal is released

I've seen a few previous posts above pulling the small pin on the front of the proportioning valve during the bleeding process.

Am I correct in the understanding pulling the pin affects the fronts only?

Reason for asking is that I have no fluid to the rear at all and was *hoping* not to have to buy a new proportioning valve.

It's getting pulled tonite either way.

Thanks
bronco_46256

Must be rears only since I didn't have any problems with mine. I cut a slot in a small piece of 1/4" plate with a hacksaw and then ground an angle on it so I could slide it under the head of the pin after removing the rubber cup. The 1/4" piece of metal held the pin out while bleeding the brakes. When I was done I remove the metal piece and everything worked fine.
 
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Bronco_46256

Bronco_46256

Sr. Member
Joined
Oct 12, 2003
Messages
428
Loc.
Elkhart
Also---is there any way to get by for less than the $90 most places want for a new proportioning valve??

If so, whats the application and part #. I saw a post where a 70's Ford truck PV can be used, but didnt list any Part #'s or more specific information.

bronco_46256
 

iwlbcnu

Bronco Guru
Joined
Nov 1, 2001
Messages
3,341
I pull the pin then bleed the rears. Are you even getting fluid to the valve? Crack the rear line at the mc and make sure it is flowing at all.
 

72Sport

Bronco Guru
Joined
Jul 8, 2002
Messages
2,954
Bronco_46256 said:
Also---is there any way to get by for less than the $90 most places want for a new proportioning valve??

If so, whats the application and part #. I saw a post where a 70's Ford truck PV can be used, but didnt list any Part #'s or more specific information.

bronco_46256

Since very few people with junk trucks flush their brake systems your chances of getting one that works are very slim. I bought five of them from the bone yard and tried to rebuild them. I destroyed one trying to get it apart and the rest were so badly rusted on the inside I scrapped them. I went to the dealer and bought a 76 Bronco p valve. The dealer wants $160(?). The part # is D5TZ-2B257-B. Since the Bronco has a very short wheel base and trucks do not, I don't think anything really interchanges with them. The just look the same on the outside.

By the way I have 76 rear brakes with the stock proportioning valve, lincoln calipers up front. Mine is pretty much stock with hardtop. My rears lock up first. Lines and everything else are new. I didn't notice it before hydroboost. You might look at BCB lbs valve or an adjustable one.

My next step is try smaller rear wheel cylinders. 76's are 15/16(?) bore. They make 7/8 (?) and 13/16 which were used on all 66-75. I also have adjustable shocks which I may adjust to keep it from nosediving when trying to stop in a hurry.
 

lars

Contributor
Been here awhile
Joined
Jun 29, 2001
Messages
3,038
Loc.
NorCal flatlands
Or buy a Wilwood adjustable valve brand new from Summit for 50 bucks or so. Then you can tune it to work for whatever weight you may be running over the rear axle, rather than hoping that the factory Ford valve will be correct. I had the same experience as 72Sport with the stock style valves. I got a bunch from the boneyard and sorted through them. They were all junk.
 

iwlbcnu

Bronco Guru
Joined
Nov 1, 2001
Messages
3,341
I think the rears lock first due to the wheel base and unloading the rear. All of mine do it stock or lifted.
 

kontinu

Sr. Member
Joined
May 20, 2004
Messages
603
Loc.
mount holly
My dad just pulled a 302 out of a 81 econoline 150. I pulled everything I thought may be use full of of it. including the proportioning valve. would that work with a 76 bronco?
 

lars

Contributor
Been here awhile
Joined
Jun 29, 2001
Messages
3,038
Loc.
NorCal flatlands
kontinu said:
My dad just pulled a 302 out of a 81 econoline 150. I pulled everything I thought may be use full of of it. including the proportioning valve. would that work with a 76 bronco?

It'll bolt in. If the guts aren't gummed up, the imbalance valve, metering valve & proportioning valve will function. Whether the proportioning valve will provide the right proportioning for your Bronco is an open question. That's why I like adjustable valves. Cheap and easy to make right.
 
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Bronco_46256

Bronco_46256

Sr. Member
Joined
Oct 12, 2003
Messages
428
Loc.
Elkhart
Pulled the pin and BOOM rear brakes. Guess that was it.

I was a little surprised to see the pin moving back and forth when the brakes were applied though. O well---either way I've got brakes.

Now--Just gotta find the dead wire between the key switch and the solenoid. Hate to run a new wire, but looks like what I will need to do.

bronco_46256
 

kontinu

Sr. Member
Joined
May 20, 2004
Messages
603
Loc.
mount holly
anyone have a pic of this (pin) and where it is. I just redid brake lines and now there not as tight as they should be. kinda mushy and soft. I probably need to do this too.
 
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