James C. Liu's Weblog

Friday November 02, 2007

Rear brakes on my venerable truck

Thought I'd do a car blog to celebrate the near passing of my truck at the 200k mile mark. Here's a saga about my last brake job...

I took my venerable truck (1992 Toyota w/ 22RE engine) a couple months ago to the mechanics shop locally to do my rear brakes. Usually, I get my ASE certified buddy to work on my truck. But he had the week off so they let a newbie do the work.

I wanted the near 200K mile car to get new bearing seals along with the rear brakes, which were now shot due to all the grease that had oozed out from the seals which had failed like 5k miles ago. I left the truck overnight, and after a number of days without it due to mailordering the parts and scheduling the work with a machine shop to press the new bearings and seals into the axle tube, I was able to pick up my truck.

The first thing I noticed when I got home was that the rear hand brake was loose. I parked on a slight incline and it was too loose to hold the truck. I hate having to go back to the shop to get them to fix something that we know they screwed up on. So I tried to adjust the tension in the cable under the car but still it was no good. I then talked to a fellow tech guy I have lunch with often at work. He's a pro who does all his own work at home. He explained that the drums on the rear have automatic tensioners. If I keep pulling the brake lever up and down, it auto-tightens and sets the tension. Just give it time and usage, he told me.

I waited 3 more days and spent time yanking the hand brake lever 20 times extra at every chance to park. It didn't tighten. It only loosened. I finally got fed up and jacked up the car myself and pulled the wheel and drum cover off. I disassembled the brake and nearly took my knuckles with it trying to free the main tension spring holding the shoes together. It was a lot harder than I recall when I did my first rear brake job on this truck almost 10 years ago. Either I was a lot weaker in the arms or something was different.

There was a star-cam screw that is about 5 inches long and sits in the saddle between the two shoes. On the outside, the tension spring holds the shoes together. On the inside, between the shoes, this screws acts like a yoke with a star cog that turns to adjust the yoke width and therefore spreads the shoes so they just press up, but not quite to the inside of the drum. After looking at the rotation of the screw (it was right hand thread on the driver side rear wheel), I realized that this couldn't be the correct yoke. For it to auto-tighten, this would have to be a left-hand thread.

I went over to the passenger side and disassembled that brake, and nearly broke my wrists trying to remove the tension spring. I finally got it off, and removed the star-screw-yoke and as predicted, it was left-hand-threaded. So I swapped the yokes, AND also, after looking at the position of the spring hooks, I swapped those as well.

Re-assembly was now MUCH easier. The springs went right back on with much better alignment and less tension. And I hopped into the driver's seat and with just a half-dozen pulls, the rear brake tightened up auto-magically.

I called the shop and told them about this to report their errors. I also emailed corporate offices for this chain with feedback. I got a canned thank you.

Lesson learned. Emersonian self-reliance wins out again. November 02, 2007 11:52 AM PDT Permalink