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I believe the 1988 to 1995 Corvettes used the same type of parking or e-brake operating system, which deflects the piston assembly towards the rotor (thus squeezing the rotor between the pads). My 94 6-speed recently failed inspection since the parking brake would not hold.
So, searched the forum for help ... not much available. OK, looked at FSM ... which is confusing and not helpful on this topic.
So started a tear down to see how this thing works ... first thing you find is that the FSM information on releasing the automatic adjuster system doesn't work on a 94 ... there are no holes for a pin!
FSM Disable Tension Info
So, I just unbolted the entire handle assembly and turned it so there was no tenstion on the operating cable.
Below, you will see the FSM diagram showing how the caliper can be adjusted to give more (or less) parking brake action.
FSM Caliper cross section showing adjuster and p-brake mechanism
As far as I can see, the adjusting screw cannot be accessed on the vehicle since the operating cable mounting bracket obscures access.
LH Caliper on-car from underside
Here is a view of a new caliper off the car showing the socket head adjustment screw.
LH Caliper
This is a view of the same caliper from above showing the parking brake mechanism in some detail.
Parking Brake Detail
Below is an image showing the lever being operated and the action it has on the piston assembly.
Parking brake operation
OK ... now we can all see how the p-brake is adjusted ... or can we?
The FSM requires that light pedal pressure be applied, and the adjusting screw be backed out until a 0.006" gap can be found between the heel of lever and the caliper casing ... BUT YOU CAN'T ACCESS THE SCREW ON THE CAR WITH THE BRACKET FITTED! And, I should add that the factory reman I used in the photos cannot be adjusted to give any gap at all!
So, my solution was to first remove the caliper from the mounting bracket, and then remove the cable mounting bracket from the caliper body. That gives access to the Adjusting screw ... I turned mine in (clockwise) 3 turns so the piston assembly was closer to the rotor. The parking brake certainly has more grip, but I might have to repeat this process until it will hold against a light clutch application.
Some useful notes:
1. The socket headed adjuster is VERY tight. I had to use a long 3/8" socket mounted allen wrench to get to get it to move. A small allen wrench was really hard to use.
2. The bolt that mounts the cable bracket to the caliper body can easily be cross threaded. The bracket is secured by two bolts. I'd suggest putting a nut and bolt through the other mounting hole and clamping it down prior to trying to reinsert the bolt (which has to be done from the underside of the caliper body too!).
If you can add more info to this ramble, and help me (and others), please do so.
It was not clear to me while comparing the FSM to my handle assembly (1993)...once I found the thread linked above, it was right there in front of me.
As for the adjustment screw, I was able to access mine (on car) by removing that lower cable bracket bolt (shown in "image 3" above). It took some time to remove the bracket bolt manually but cost less than buying the appropriate allen socket. I first used a mirror, but found it easier to just get under the car (jackstands please!) to access this area. It took some trial and error but passed RI safety inspection just recently!
Last edited by brokencrank; May 1, 2016 at 11:17 AM.
Didn't find that post when searching ... great find, and very helpful! I can now refit the handle and try and release the tension.
And I agree that you can get to the adjusting screw if you remove the cable mounting bracket (by remove the lower caliper retaining bolt and the fixing bolt), but it is a tight squeeze if you are using a socket head allen wrench (the chassis stuff gets in the way!). If you are lucky and the screw moves with a simple allen wrench, it is do-able. If I had access to a hoist, I'd do be happy to try it though
It was not clear to me while comparing the FSM to my handle assembly (1993)...once I found the thread linked above, it was right there in front of me.
As for the adjustment screw, I was able to access mine (on car) by removing that lower cable bracket bolt (shown in "image 3" above). It took some time to remove the bracket bolt manually but cost less than buying the appropriate allen socket. I first used a mirror, but found it easier to just get under the car (jackstands please!) to access this area. It took some trial and error but passed RI safety inspection just recently!
This is a follow-up to the excellent post by MXW128 (post 6).
In his post, he shows where the locking pawl is located. I've got a few additional photos that might help folks trying to release tension on the parking brake.
Photo One: shows the brake spring tool used to lift the pawl:
Photo Two: Shows the tool in use:
Photo Three: shows how the cable securing reel can now be pushed fully forward, and held in-place using a screwdriver:
This will fully release the parking brake mechanism and make it a little easier to move the adjusting screws on the caliper.
After suggesting that the parking brake adjustment would be impossible to do on the car (first post), I now have to apologize to Brokencrank: it is possible to do!
Photo one: shows the caliper being rotated after taking out one mounting bolt.
Photo Two: shows the hex wrench inserted into the adjusting screw.
Please note: the adjusting screw can be very difficult to turn, and if you are in any doubt as to whether it will move, you are advised to remove the parking brake cable bracket to give clear access. Hopefully, your hex wrench won't break in the head of the adjusting screw (yup, it did ... I now have a new rebuilt caliper on the RHS!)
1994 Parking Brake Problems: Sharing Info
