FYI FORD - MustangSteve's Ford Mustang Forum
The Internet's Most Knowledgeable Classic Mustang Information
IF YOU HAVE A QUESTION ABOUT CLASSIC FORD MUSTANGS, YOU HAVE COME TO THE RIGHT PLACE!
MustangSteve has over 30 years of Mustang experience, having owned 30 of them and restored several others. With the help of other Mustangers, this site is dedicated to helping anyone wanting to restore or modify their Mustang.... THERE ARE NO DUMB QUESTIONS!!!!!
Visit MustangSteve's web site to view some of my work and find details for:
FYIFORD Contributors' PICTURES - Power Brake Retrofit Kits for 65-66 Stangs - Classic Mustang FAQ's by MustangSteve - How to wire in a Duraspark Ignition - Mustang Ride Height Pictures and Descriptions - Steel Bushings to fit Granada Spindles to Mustang Tie Rods - Visit my EBAY store MustangSteve Performance - How to Install Granada Disc Brakes MustangSteve's Disc Brake Swap Page - FYIFORD Acronyms for guide to all the acronyms used on this page - FYIFORD Important information and upcoming events

You are not logged in. Would you like to login or register?

9/22/2017 8:52 AM  #1


proportioning valve with all drum brakes

I have a 65 mustang with DRUM/DRUM none power brakes. It has a single MC that runs into what i look call a Proportioning valve and then to each from and the rear drums share a line which is T off in the back. 
Engine is the 289

The rear brakes are locking up driving down the road and then the entire car stops. 

What should i do to correct this issue and how to do it without converting to disc. 

Last edited by swolfert84 (9/22/2017 8:52 AM)

 

9/22/2017 10:04 AM  #2


Re: proportioning valve with all drum brakes

First & foremost:   Welcome to FYI Ford!
Second:  You placed your post in the "tips & How to's section of the Forum.  You will get more attention, if your questions are asked in the "technical discussions" part of the forum.
Third:  Assuming that your parking brake is functional, and properly adjusted, your brake issue may well be related to the flexible brake line that goes up and over the rear axle.  When those hoses get old, the inside of the hose deteriorates, and the inside collapses and restricts the flow of brake fluid.  It may look perfect on the outside, and be junk on the inside.  What may be happening is, when you push on the brake pedal, it properly forces brake fluid to the rear brakes, and applies the rear brakes, but when you take your foot off the brake pedal, the restriction in the bad hose restricts the flow of fluid back to the master cylinder reservoir.  Due to the restriction, the rear brakes stay engaged.
Replace the hose, and bleed the rear brakes.  It's cheap, and if you don't know its age & condition, it's probably time to change it, anyway.
Hopefully others will chime in.

 

9/22/2017 10:07 AM  #3


Re: proportioning valve with all drum brakes

Hi , if is the oem proportional valve could be not working properly after all these years .
I dont believe you could repair , simply put it new .
Maybe you should check also the distance adjuster of drum shoe if works .
You can check the front line pressure and back and see how much difference ,
Or  simply  you could have some clogged hose that happens when have old Rubber hose and old oil.
I will check all if talking on brakes

 

9/22/2017 10:16 AM  #4


Re: proportioning valve with all drum brakes

Welcome to the best place around. You will get more responses if you post this in the tech section.
My WAG without further information, is a broken spring in one of the rear brakes. pull the drums off and see what you can see.
 


"Those telephone poles were like a picket fence"
 

9/22/2017 2:36 PM  #5


Re: proportioning valve with all drum brakes

There is no proportioning valve on a 65 drum brake Mustang.  It is simply a brass block where all brake lines come together.
If rear brakes are locking up, it is probably one of two things:
1.  Old rubber brake lines are swollen internally, cutting off return flow.  (see pic)
2.  Grease from leaking rear bearing have contaminated the brake shoes.   I never have figured out how good old slippery grease makes the brakes lock up, but it sure will do it if it gets on the brake shoes.



 


Money you enjoy wasting is NOT wasted money... unless your wife finds out.
 

Board footera


REMEMBER!!! When posting a question about your Mustang or other Ford on this forum, BE SURE to tell us what it is, what year, engine, etc so we have enough information to go on.