rear brakes locking up ( after light off road excursion )

ok so i went out shooting (with my 9 year old girl and 1 of her little friends) it was raining, so the dirt road in the desert was wet, now on the way home my left rear drum is locking up when i brake and Jeep wants to go squarrly, have to counter steer to keep it straight

89 Xj with drums in the back

what could be the culprit? dirt inside drum? bad shoes? or did something lock/break?

the Jeep still brakes but i have to depress the brake pedal very hard and it locks the Right rear wheel a around 5-10mph

image. The original image is sized 1167x875.

Drum brake lockup can be caused by several things. The most common is usually oil on the brake shoes. Check to make sure the rear axle seal is good and not leaking.

Second can be caused by crap in the drums. It can alternately cause too little braking and then minutes later cause lockup. Take it to a quarter wash and crawl under and spray water between the backing plate and the drum at the top, flushing the brakes out.

Third can be due to the shoes being swapped, leading shoe vs trailing shoe.

Residual water itself can cause it. If it goes away after braking gently it's just the extra grip of the wet surfaces. It happens in mine frequently during rainy days.

Mine does that pretty much every time, one of the draw backs to drums. I advoid mud at all costs too. It's water or dirt, unless the axle seal or brake cylinder is leaking.

old_man said:

Drum brake lockup can be caused by several things. The most common is usually oil on the brake shoes. Check to make sure the rear axle seal is good and not leaking.

Second can be caused by crap in the drums. It can alternately cause too little braking and then minutes later cause lockup. Take it to a quarter wash and crawl under and spray water between the backing plate and the drum at the top, flushing the brakes out.

Third can be due to the shoes being swapped, leading shoe vs trailing shoe.

Click to expand...

that was my issue before I knew there was a proper direction for them, the shoe was pushing out and away, causing it to rub the wall of the drum. I have new brake cylinders I need to install to see if that was part of the problem too.

I had a spring fail and the adjustor lock and adjustor flowing around in the drum getting caught every once in a while.

When mine do that the first thing I do is check the wheel cylinders. Brake shoes are porous, suck up fluids, get soft and grab. When my shoes get brake fluid soaked I usually toss them. In a pinch you can burn them lightly with a torch and turn the brake fluid into carbon which is better than the brake fluid sucking up moisture. Gear oil soaked I toss them.

If you carefully pry the rubber boot off the end of the wheel cylinder, just a little, you can see if fluid is seeping past the piston. If you pry the rear of the boot open you have to remove the shoes to get it back on there again. I use a tiny screwdriver, being careful not to rip or cut the boot. Often people mistake a brake fluid seep for a axle seal seep, you can smell the difference.

A bucket of suds, a scrub brush, a bottle brush and cleaning out the drum and brake shoes once a year works wonders on longevity. I wash and rinse with really hot water. I live in snow country, road salt really messes up the rear brakes.

If yo do any mudding or even just mud puddles, the muddy fluid gets into the brake drums, evaporates and leaves dried mud and sand behind. That sand can really wear out a pair of brake shoes quick.