Rear brakes on a 1989 F-250

[OG-Larryw1]

the rear brakes lock on this 1989 F250 xlt w/5.8 cu in

I pulled the rear apart and found
RR - oil soaked (Gear oil) Wheel, cyl bad, shoes fell apart
LR - wheel cyl siezed

repl both Wheel cyl and shoes, springs turned drums and flushed fluid.

adjusted the shoes to full lock and then backed stars off until wheel turned with slight drag.

rear brakes locked again?


Fluid was black

I believe the owner had replaced front pads prior to problem.

note the vehicle didn't bleed easily. but did bleed.

I am not an expert on fords but have some knowledge
'
mostly Volvo my ford experience is from my own vehicles. 1st time for brake problem like this any help would be good
Larry

 

[Zembonez]

Locking generally means something is jammed from being incorrectly installed (or came loose). It's pretty easy to do when you reassemble these.

Have you pulled it back apart?

I'm going to remove the duplicate thread and we'll use this one to discuss this.

 

[OG-Larryw1]

I got an Idea

update:
If I open the bleeder on the proportioning valve the brakes would free up.
so I repeated this about 4 times. every time the brakes locked up and every time they freed up with a slight and quick opening of the proportioning valve bleeder. I then tapped on the valve in the area if the big nut (forward end of the valve) but still on the side of the body. the body of prop valve. now the brakes don't lock up any more.

I recommended to my friend that he should replace all hydraulic pieces. Calipers, Master cyl, proportioning Valve. due to the fact that the wheel cyl were seized due to corrosion and that the brake fluid was black.

The rear brakes locking up was his original complaint. When I pulled the rear drums and found oil soaked shoes and that most of the linning had com off so he was metal to metal on the drums. I also found the wheel cyl siezed. I assumed and recomended we start with the rear brake job. now that they are done I have discovered the above!

Any other thoughts let me know?

 

[OG-Larryw1]

Locking generally means something is jammed from being incorrectly installed (or came loose). It's pretty easy to do when you reassemble these.

Have you pulled it back apart?

I'm going to remove the duplicate thread and we'll use this one to discuss this.

I wasn't sure where to post this issue.

 

[Zembonez]

I wasn't sure where to post this issue.

No problem at all.

If you have them freed up, I'd flush out ALL of that old fluid. Pretty easy. Just keep the reservoir full of fresh fluid and bleed them all until you see clear new fluid. It can make a LOT of difference.

 

[OG-Larryw1]

I wasn't sure where to post this issue.

No problem at all.

If you have them freed up, I'd flush out ALL of that old fluid. Pretty easy. Just keep the reservoir full of fresh fluid and bleed them all until you see clear new fluid. It can make a LOT of difference.

That was done when I put the rear together. I pulled the M/CYL resevoir cleaned it and flushed the whole system. Knowing that the fluid was black I flushed it. I didn't do the original bleeding of the rears until I had started the complete flush.


I told my friend about all these possabilities before I even started. I showed him the fluid. I told hime if his Master cyl wasn't bad now it could fail at any time due to the condition of the fluid.

 

[Zembonez]

I guess I didn't read your first post correctly.

Once the system is let go that far, it's certainly best to replace the parts if financially possible. What you describe sounds like a possible bad proportioning valve, but it's really hard to say without seeing it. At the very least, I'd replace BOTH wheel cylinders and the valve to start (I realize you have already done the wheel cylinders.)

 

[OG-Larryw1]

I guess I didn't read your first post correctly.

Once the system is let go that far, it's certainly best to replace the parts if financially possible. What you describe sounds like a possible bad proportioning valve, but it's really hard to say without seeing it. At the very least, I'd replace BOTH wheel cylinders and the valve to start (I realize you have already done the wheel cylinders.)

thank you for your input. I am getting prices on the parts monday

 

[Bigredmariner]

It does sound like a proportioning valve issue. That's what I would replace next too.

 

[OG-Larryw1]

"WOW" Looking for the Prop. Valve I was told Dealer item $508.00
my poor friend!!!!!!!

I did locate used ones at a couple of diff wrecking yards. $75 but first I think I will pull his and open it to see how it looks. I am curious.

the Calipers 41.48 each exch.
the M/C 41.50 new
those are not too bad.


of course another quart of Brk Fl.