Stupid parking brake adjusting (Page 1/1)
pontiacfierokid1985 JUN 12, 08:39 PM
So I installed new pads and rotors in the rear before doing this I took the calipers off to be painted parking brake worked fine parked on a grade 5% hill car didn’t move out of gear and brake applied. Now that it’s all back together I lost the parking brake. I have a safety inspection coming up next month and need to have this in order to have a passing safety car. If not a I get a big fat red R for reject and can get ticketed every time if I get pulled over. So how the heck do I adjust this correctly to get it to work working with the 6 clicks of engagement like I did before
dremu JUN 12, 09:12 PM
Searching will lead you to tons of info.

Read the Ogre's Cave, linked at the top.

One thread here suggests this procedure to make the calipers self-adjust:

1. Set the e-brake (at least as far as you can).
2. Step firmly on the brake pedal and HOLD.
3. Release the e-brake.
4. Release the brake pedal.

You can also put a long needle nose vice grip onto the lever to manually activate it; see https://gafiero.akroncdnr.c...oBrakeAdjustment.pdf

The service manual tells you, in short, to tighten the adjuster until either parking brake lever just lifts off the caliper body, then loosen it until the lever touches again.

It's fiddly, and I find requires much patience -- and an inspection mirror is handy to judge whether the lever has lifted yet (assuming you have the car on stands with the wheels off, vs are working on a lift.)

-- A

[This message has been edited by dremu (edited 06-12-2020).]

Dennis LaGrua JUN 12, 10:08 PM
Did you align the caliper piston face to the tabs on the brake pads? Did you use the clips to keep the pads aligned before assembly. If you did you just tighten the eBrake cable until the eBrake arms just begin to move off of their stops on the calipers. In other words you want no slack in the cable. Then pull on the lever several times to adjust.

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cmechmann JUN 12, 10:12 PM
This is an issue with earlier GM calipers with integral parking brake. If the service brake is applied before the parking brake assembly in the caliper piston is ratcheted out, the parking brake will not work properly. Inside the caliper piston is a cone and screw assembly, with a spring to help keep the cone against the inside of the piston. If the service brake is applied before bringing out the parking brake, the piston is pushed out too far for the cone spring to keep the cone against the piston.
When replacing pads or other brake work, the piston is normally spun to get it to retract. Before "pumping" the pedal up, use vise grips on the levers. The same way that the cable would apply it. Using the parking brake won't work due to not rotating the lever far enough to "ratchet" out the piston. Each time you apply the lever, you should notice that the piston moves out a little each time. If it does not move out and stay, either the lever was not applied enough or the piston is bad. If it moves out and back in when the lever is released, the cone is stuck. Also if there is any fluid at the vent hole in the middle of the piston, it is bad. It was very common to have to replace caliper pistons due to one of these issues. However if the parking brake was working normal before and you used it regularly, they should be OK. It is getting hard to find right side pistons. Rebuilt my calipers last fall and used the last one I had.
Another note: When retracting the piston back, make sure that one of the depressions/notches in the piston face will line up with the protrusion on the inner pad. If not the pad and or piston can bind. That keeps the piston from rotating in it's bore.
Now say you have applied the service brake before "ratcheting" out the piston and now you have little to no parking brake or your service brake feels low, there is still hope. Without having to remove the caliper and retract it again. If this is the case there should be a gap between the piston and the brake pad. You can use that gap to push the piston back up against the cone. Being careful not to knock the antirotation/rattle clip off the piston or pad. Then adjust out by the levers.
Note: This was an issue with all late 70s- 80s- early 90s GM integral calipers. To the point that GM advised using the parking brake regularly to keep the piston assembly from sticking, keeping good pedal height, and keeping proper parking brake adjustment. You should not nee to adjust the cable. And if you do, may sure the lever returns all the way back on the stops when the parking brake is released. GM also started using the pump action type parking brake pedal on many cars to have more lever movement to help.
theogre JUN 12, 11:44 PM
See my Cave, Rear Brakes

Rear Piston(s) can work then "go bad" often very easy. More after you did a "brake job" plus whatever extra work. Even more if you compress the piston by turning for 84-87.

Before you blame the pistons...
Check P-brake cables.
Common Example:
Grab outer jacket of wheel cables and pull away from each end.
Jackets can rust out at the ends and break there causing problems.
I don't mean just the locking "ears" break, the crimped end or jacket itself breaks.

Even w/ a P-brake that works 100%...
There are directions you should follow to apply.
In short... Push pedal down firm then pull handle.
Read OM get @ http://www.fieronews.net/fusion/downloads.php

Cable adjustment is similar.
See http://www.fiero.nl/forum/F...HTML/143201.html#p31

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