The park brake on my Formula never worked right since the day I got it back in 94... until about a year ago. I decided it was time to fix it, and I expected to have to replace cables and maybe calipers. I had to replace a small part I got in a rear caliper rebuild kit for 84-87's.
On each rear caliper, the brake cable connects to the park brake lever. Between that lever and the caliper should be a thrust washer. My Formula was missing one of those. Without the thrust washer, the park brake will not adjust properly. I had had a brake job done years ago by a shop (mistake), and I had them fix the park brake. Turns out that all they did was to adjust the cable adjuster to it's stop, resulting in the park brake handle engaging where it should, BUT only one caliper was grabbing, because the other one wasn't adjusting.
So... to fix it, I had to:
- Remove the cable and spring from the park brake lever.
- Remove the park brake lever.
- Work the internal park brake mechanism to bring the pad in contact with the rotor. You should be able to fit a wrench on the shaft and turn it until the pad tightens against the rotor.
- Install the thrust washer and park brake lever, and just snug down the nut, because you may be removing it again.
- MOST IMPORTANT STEP: Verify that the brake lever is positioned properly, and that the park brake mechanism in the caliper is working. The brake lever should have a range of motion that allows it to reach the stop on the rear of the caliper, and engage the park brake when pushed forward. If it won't, attempt to reposition the lever (remove it, rotate it on the shaft, and re-install) to attain this. If there's no position that works, the internal mechanism is not working properly, and the caliper will need to be either replaced or cleaned out, and cleaning it out MAY not work.
- Once the lever is positioned so that it will engage the park brake, AND it will reach the stop, torque the nut holding the lever to the caliper.
- Repeat for the other caliper.
- Re-connect the cables and springs to the park brake levers on both sides. If there's not enough slack in the cable (as was the case with mine), the cable adjuster will need to be adjusted to increase cable slack.
- Adjust the cable adjuster until there is just enough slack to allow the park brake levers to rest on the stops.
That should do it.
One caveat if replacing the thrust washer. When the new thrust washer was installed, it was a very tight fit. There was slight rust on the surfaces that contact the thrust washer, and even though I removed the rust, the surfaces remained rough, resulting in the brake lever requiring a lot of force to move. MUCH more than the other side. So, I swapped the thrust washers between the left & right calipers. The result was that the repaired caliper freed up some, and the other caliper stiffened up some, and they both required about the same force to operate.
My brakes and park brake work great now.
Also, whenever you apply the park brake, first press the brake pedal. You should feel the pedal go down slightly when you pull up on the brake lever.
[This message has been edited by Formula Owner (edited 03-08-2011).]