Mastertechtim is right about a sticking parking brake cable. To check for that, first tug on one of the cables ahead of the wheel and see if it releases by itself. If it's stuck, you will also see that one or both shoes are not contacting the large anchor pin on top. The third clue involves moving the parking brake strut rod between the two shoes. It has an anti-rattle spring on one end. Use your thumb to push the strut rod to compress that spring. If it moves even 1/16", it is free; good news. If you can't move the strut rod at all, it is holding the shoes out. Even if you could get the drums on, this problem will cause the shoes to grab resulting in easy rear wheel lockup under light brake pedal pressure.
Check that the shoes are centered on the backing plate. If the bottoms are shifted to the side a little, the two shoes will form an oval, not a circle. Just bop the shoes back and forth with the heel of your hand.
Here's two things you wouldn't expect until you saw someone do them. The first is putting the parking brake strut rod in upside down. Many of them are not a straight piece of metal, rather, they have a little hump in the middle to clear the hub of the drum, (Caravan / front wheel drive vehicle) or the axle shaft (rear wheel drive). If you're lucky, the drum won't go on. If you're not lucky, the drum will go on but will make a grinding noise that can be hard to figure out.
The last thing that you would never expect is misplacement of the automatic adjuster screw. It goes between the web of the shoes, not the frame that the linings are riveted or glued to. If it's in the wrong position, the shoe diameter will be about 1/4" too big.
If any of these things that involve mispositioned parts,
Thursday, March 19th, 2009 AT 11:13 PM