What would cause a tire to lock up?

[TunnelFear]

Today as I was driving to work I managed to get a big scare, I went to stop, going 45 or so, and the drivers side rear tire locked up on me, under minimal braking pressure, IE I touched the pedal and the wheel was locked. It was the first time I had to use the brakes today, besides stopping myself when I backed out of my driveway. Shaking it off, I limped it the last mile to work (thankfully it's only a 2 mile trip) where it locked up again when I touched the brakes. So there my Jeep sits, until later tonight when there is no traffic and I can limp it home. What could be causing this?

Here's a little info.
1989 Jeep Wrangle YJ - Dana 35 axle - Drum brakes
I changed the brakes, all new everything, in the rear, back in February; have not had a problem till now.
Powertrax locker in the rear.
33X12.5 BFG MT
4" Suspesion lift
Revolver Shackles
No air pressure changes in the tires.
No noticeable excessive wear on the tires, as I have put maybe a 700 miles on it since February.

 

[CDW6212R]

Rear drum brakes have a lot of potential odd symptoms. Check the rear brakes, something needs help. Be sure that the cylinders don't leak, as well as the axle seals not leaking.
Are you positive that the shoes were installed correctly. The front shoes are a different size than the back pair. One has more friction material on it. Good luck,

 

[Creager]

NON-ABS?

Just driver's side?

that is weird

Yeah visually inspect everything... im thinking the brake adjuster is WAY out of adjustment (needs to be backed off a lil bit)

 

[ExplorerDMB]

Check your wheel cylinders if everything else looks to be ok. Make sure the primary and secondary shoes are put in the right spot. How did you adjust the drums? Tighten it up all the way til you can't turn the trum and then backed it off? And you did back up after you adjusted the brakes correct? That sets the adjusters!

-Drew

 

[TunnelFear]

Well I took off the tire and drum today and one of the shoes was completely off of the shoe backing plate. Not entirely sure how that happened, as I see no leaks anywhere and my master cylinder does not look low. Would that have been the culplrit? Or was that just an effect of the wheel locking up?