rear brake keeps tightening

[Greenie]

On a 93 F-250... The self adjuster keeps taking up slack to the point of heating up the brake and boiling the fluid in the wheel cylinder and adjacent brake line. Last week I replaced the shoes, wheel cylinder, springs and adjuster with new parts. The drum went on very difficultly even though the adjuster was bottomed out. I've taken the truck on a few short rides and the drum is getting hot. The tight shoes aren't getting any better.
The same wheel has been problems for a few years now - it keeps tightening up and getting hot.
Any ideas what's going on?

 

[Exekiel69]

Are You sure it is the hardware and not the brakes/proportioning valve? This happened to Me (different setup) and someone told Me to raise the tire and turn it with the engine off then do the same with the engine running to rule out the possibility of the brake system building pressure on that particular line. You can also replace the adjusting bolt if You didn't already and make sure the little arm and spring keeps it from turning.

 

[typ4]

Make sure the ebrake cables are not seizing, common problem.

 

[Greenie]

I'll check the ebrake. This proportioning valve - would it just affect one side?
The truck has never had really good brakes - The anti-Lock brake system is pretty primitive.
Thanks for the suggestions!

 

[icanfixall]

These brake systems have a left side and a right side. Could someone installed the left side on the right side??? They are left and right hand threads on the adjusters as I recall. If this has happened either by you or someone else the brakes will tighten up all by them selves...

 

[sassyrel]

These brake systems have a left side and a right side. Could someone installed the left side on the right side??? They are left and right hand threads on the adjusters as I recall. If this has happened either by you or someone else the brakes will tighten up all by them selves...

agree---have found this more than once on a truck--usually by farmers in this area----------

 

[Popeye2347]

I could be wrong, but I think if the adjusters are installed on the opposite side then they will loosen, not tighten, when activated.

I suspect you have a defective flex hose, allowing fluid to apply the brakes but restricting flow back to the master cylinder.

Hard to troubleshoot from a distance however.......

 

[Greenie]

The last shop that worked on the brakes did put the adjuster in backwards - the self-adjusting lever loosened rather than tightened the brakes.

 

[Agnem]

Yup. I vote slack adjuster problem.

 

[Dsl_Dog_Treat]

If you're sure the brakes are installed correctly, I'm gonna play devils advocate here.

It's possible that the inner axle bearing is worn and causing the vibrating shaft to shake the adjuster tight.

I experienced that a couple of years ago and it bout drove me nuts trying ti figure it out till I popped the rear diff cover off and started probing around.

I found a very sloppy inner axle shaft bearing on the drivers side to be the cause of the problem.
It was tightening the shoes up fast enought that every 50 miles I had to back them off.