Rear Brakes Not Locking up????
 

Hello
I'm Asking For A Buddy Who has A 1994 Cherokee xj Sport, And Driving Around Town Vehicle Stops Great But When We Are Out Wheeling, If He Has To Go Down A Hill Standing On the Brakes the Fronts Will Lock Up But Rears Continue To Roll. It Has A Fresh Brake System, New Master, New Proportoning Valve, New Front And Rear Pads Shoes Drums And Rotors, But It Will Still Lock Up Front And Rear Drums Will Roll. He has A Mild Lift With 33' under it. but everything else is stock. is this a common issue with this model? any help is appreciated, thank you.

Manually adjust the rear shoes.

X2

Also be sure the self adjuster as been assembled correctly. The star wheel arm should rest in contact with the star wheel. If it doesnt something is wrong. I've seen it often.

Thank you for the suggestions. The rear brakes are adjusted properly and all the hardware is new. It feels like I'm losing pressure to the rear wheels while off roading. They grab for a sec then start rolling. But it has a new master and Proportioning valve. And no fluid loss anywhere else. I keep reading these thing only have 80/20 braking unlike the rest of vehicles that are 60/40. Any suggestions on a adjustable porportioning valve? Thank you

Check the rubber brake lines for weak spots.

Thank you. We have checked the brake lines while on a lift. They feel nice and solid and no signs of bubbles or weak spots. This one has me stumped. It acts like its bleeding off internal but everything is new and there has been no difference from the old parts.

I take it that the pedal gets soft or it bleeds off?

Nope that's the weird part is it stays firm. But it only does when we are out wheeling. And going up or down hills hitting the brakes. The fronts will lock and the rears will lock up for a few seconds then roll causing me to slide back down. That's why I'm thinking it's the proportion valve. it have been replaced but everything I find say it's a 80/20 braking and maybe its releasing the pressure allowing the tires to roll. The rear brakes are new and adjusted properly. The parking brake will hold the truck. Could this just be a treat for these jeeps? I've only read a few other post with the same thing happening and they never clarified what fix it or if they ever did. So any help I can get is appreciated.

The front had a much higher brake bias than the rear so the front will always lock up sooner. When offroading in 4x4 the front and rear will lock up evenly since in 4x4 the front and rear axles are connected by the transfer case and driveshafts.

Yeah, if you're in 4 low you shouldn't be having this problem // confused