Touchy rear brakes, locking up

[Jorge6.5]

Well the temps have gone up to the 40s here for the past couple of days and have been getting rain. Yesturday I have taken the truck out and when I would go to use the brakes, the rear breaks would lock up when going slow with just the slightest touch of the brake pedal.

Only thing I can think of why this is happening is maybe the axle seals are shot and now the gear oil has soaked into the brake shoes and now that there is lots of rain/moisture, that could be pulling the oil from the shoes causing them to grab the way they do.

Not really sure what else could cause this.

Thanks for any and all suggestions guys. Have a great weekend!

 

[shortchevy]

if the axle seals are leaking you will most likely leave puddles. I would guess that your wheel cylinders are going.

 

[TylerZ281500]

its only happening when temps change? i know if rwal is going bad or the proportion valve is failing it can lock up the rears and stuff like your describing.

 

[Jorge6.5]

if the axle seals are leaking you will most likely leave puddles. I would guess that your wheel cylinders are going.

No puddles at all. Maybe they aren't leaking that bad or just enough to get oil on the shoes. The wheel cylinders are brand new.

 

[Ruger_556]

Leaky wheel cylinders won't make them grab... Something else is wrong.

 

[Jorge6.5]

its only happening when temps change? i know if rwal is going bad or the proportion valve is failing it can lock up the rears and stuff like your describing.

Not exactly just from temp change but instead when there is a lot of moisture or dampness in the air like rain.

What is the rwal? Where is the proportionong valve? I didn't know this truck had one.

 

[TylerZ281500]

rear wheel anti lock, prop valve is underneat your brake fluid reservoir and master cylinder and stuff. all trucks have prop valves. yours is a 90 so i believe it has rear wheel anti lock brakes like my 88 did. when that went on the frits my rears would lock and unlock at random times or straight up lockl up when i hit the brakes.

 

[michael hurd]

All of these trucks I have driven with the OE compound shoes have very responsive IE: locking up rear shoes when it's damp. I have a feeling it has to do more with the shoe lining than anything, I am sure that a semi metallic would be not as bad.

 

[shortchevy]

Leaky wheel cylinders won't make them grab... Something else is wrong.

wow... dont know what I was thinking when I posted that... haha.

 

[454cid]

My truck does this too. It's always done it to some degree, but has gotten worse. I've wondered if maybe I reversed the shoes last time I had the brakes apart. Also, I've never replaced the hardware, and the truck has many miles on it, now.

No way, I'm pulling it apart until it gets warm, though.