e-brake
Drifting
Joined: Apr 2003
Posts: 1,323
Likes: 2
From: Castle Hills Texas
Try doing a search on adjusting the e-brake. You will find all sorts of useful info on here. You might find this of interest as well:
http://willcoxcorvette.com/repairand...lp.php?hID=141
The e-brakes on these are notorious for doing exactly what you are describing.
http://willcoxcorvette.com/repairand...lp.php?hID=141
The e-brakes on these are notorious for doing exactly what you are describing.
Last edited by Crash80; Jun 28, 2010 at 03:30 PM.
Safety Car
Joined: Apr 2000
Posts: 3,802
Likes: 61
From: Wichita KS
The procedure is in the GM Chassis Service Manual (shop manual).
You have to take off the wheel and line up the large hole in front of the rotor hat with the adjustment wheel on the bottom if the parking brake.
Using the screwdriver engage the teeth on the adjustment wheel and turn the adjustment wheel down to tighten and up to loosen the brakes.
IIRC you are supposed to tighten until you cannot move the rotor then back off about 2-3 clicks.
Repeat for the other side.
cc
You have to take off the wheel and line up the large hole in front of the rotor hat with the adjustment wheel on the bottom if the parking brake.
Using the screwdriver engage the teeth on the adjustment wheel and turn the adjustment wheel down to tighten and up to loosen the brakes.
IIRC you are supposed to tighten until you cannot move the rotor then back off about 2-3 clicks.
Repeat for the other side.
cc
Drifting
Joined: Apr 2007
Posts: 1,970
Likes: 45
From: Cameron Park CA
In my experience with my '69, contrary to what is often said here, the parking brake on these cars works well when all the parts are correct and not worn out.
Stretched cables, worn brake shoes, etc., will all contribute to poor performance. With good parts, and proper adjustment per the factory service manual, these parking brakes work well enough to hold the car on a moderately steep hill.
Pete
Stretched cables, worn brake shoes, etc., will all contribute to poor performance. With good parts, and proper adjustment per the factory service manual, these parking brakes work well enough to hold the car on a moderately steep hill.
Pete
Safety Car
Joined: Aug 2001
Posts: 4,883
Likes: 11
From: North Easton Mass
With the wheel off the ground there is a lot of extra friction in the driveline due to the u-joints binding. The best adjustment procedure I have seen so far requires disconnecting the driveshaft from the hub, adjusting the e-brake and then re-connecting the driveshaft. I didn't want to go that far when adjusting mine, but when I jacked up the trailing arm to get the driveshafts almost level, I found that I could tighten the adjuster screw a lot more from the point where it was dragging before. Before my next inspection I'm going to disconnect the driveshaft and do the adjustment again.
Rick B.
Rick B.
Drifting
Joined: Apr 2003
Posts: 1,323
Likes: 2
From: Castle Hills Texas
Courtesy of Gerry72:
C3 parking brakes are difficult for shadetrees to correctly adjust due to some design issues that aren't well addressed and just experience shortfalls.
If you try to adjust the shoes by turning the star wheel until you feel a drag on the rotor/drum you'll confront the design issues. They have to do with the halfshafts going into a bind when the rear suspension is in full droop and the limited slip driving the opposite wheel which will also be in a bind as well as contributing to drag and shoe friction. There is a very specific adjustment method that must be followed, otherwise you'll not have full shoe contact and may also destroy the shoes.
The meat of the issue is that you have to loosen the adjuster cable to the point where there is no tension on the cable. The cable moves the top of the shoe out in an arch. The bottom part of the shoes only pivot. So, for the most part, what you are adjusting with the star wheel is the bottom part of the shoe. Once you have the bottom part of the shoes adjusted on both wheels, you can put tension on the cable so that when the handle is pulled, the shoes come into equal contact with the drum.
The tricky part, again, is knowing when you have the bottom part of the shoes in proper contact. If you are off, you'll have contact difficiencies in either the top or bottom of the shoes on the drum. With improper adjustment, the brake mechanism will perform poorly or you'll destroy the brake lining...or both.
So, how does the shadetree deal with this? Not easily. The best way is to disconnect the halfshafts at the spindle flange (not the differential stub axle) so that both rear wheels are not connected to the differential and are free to rotate without any halfshaft binding, opposite wheel drag, or drivetrain drag. Doing it this way will allow you to have a very good tactile sense of when the bottom part of the shoe is contacting the drum. You want light contact so that you can hear the shoe contact throughout the full revolution of the wheel. Once you have the bottom shoes adjusted on both sides, you can tighten up the cable. With the handle fully retracted, you start adjusting the cable until you hear and feel the full shoe lightly contact the drum. It should be an equal feel and sound on both sides. The drag from the contact friction should be very, very light. Once you think you have the right cable adjustment, pull up on the handle. You should get around three clicks and then strong resistance. If all seems well, button it up and give it a test.
You can do it without disconnecting the halfshafts but, again, for a shadetree, you'll be fighting the ills and your experience level. You'd at least have to jack up both sides of the spindles to put the halfshafts at ride height so you can keep them from binding. Of course, in adjusting the star wheel, you are essentially doing the adjustment based upon your experience in doing it this way. For the most part, you're working from hearing only since you have drivetrain drag contributing to the brake friction.
It does take longer to do it by disconnecting the halfshafts but the outcome is usually better for the shadetree. And it's not like you'll be doing this every couple of months. If you have a good parking brake assembly, you should have to do this only once. So your time is sort of like an investment in the outcome.
C3 parking brakes are difficult for shadetrees to correctly adjust due to some design issues that aren't well addressed and just experience shortfalls.
If you try to adjust the shoes by turning the star wheel until you feel a drag on the rotor/drum you'll confront the design issues. They have to do with the halfshafts going into a bind when the rear suspension is in full droop and the limited slip driving the opposite wheel which will also be in a bind as well as contributing to drag and shoe friction. There is a very specific adjustment method that must be followed, otherwise you'll not have full shoe contact and may also destroy the shoes.
The meat of the issue is that you have to loosen the adjuster cable to the point where there is no tension on the cable. The cable moves the top of the shoe out in an arch. The bottom part of the shoes only pivot. So, for the most part, what you are adjusting with the star wheel is the bottom part of the shoe. Once you have the bottom part of the shoes adjusted on both wheels, you can put tension on the cable so that when the handle is pulled, the shoes come into equal contact with the drum.
The tricky part, again, is knowing when you have the bottom part of the shoes in proper contact. If you are off, you'll have contact difficiencies in either the top or bottom of the shoes on the drum. With improper adjustment, the brake mechanism will perform poorly or you'll destroy the brake lining...or both.
So, how does the shadetree deal with this? Not easily. The best way is to disconnect the halfshafts at the spindle flange (not the differential stub axle) so that both rear wheels are not connected to the differential and are free to rotate without any halfshaft binding, opposite wheel drag, or drivetrain drag. Doing it this way will allow you to have a very good tactile sense of when the bottom part of the shoe is contacting the drum. You want light contact so that you can hear the shoe contact throughout the full revolution of the wheel. Once you have the bottom shoes adjusted on both sides, you can tighten up the cable. With the handle fully retracted, you start adjusting the cable until you hear and feel the full shoe lightly contact the drum. It should be an equal feel and sound on both sides. The drag from the contact friction should be very, very light. Once you think you have the right cable adjustment, pull up on the handle. You should get around three clicks and then strong resistance. If all seems well, button it up and give it a test.
You can do it without disconnecting the halfshafts but, again, for a shadetree, you'll be fighting the ills and your experience level. You'd at least have to jack up both sides of the spindles to put the halfshafts at ride height so you can keep them from binding. Of course, in adjusting the star wheel, you are essentially doing the adjustment based upon your experience in doing it this way. For the most part, you're working from hearing only since you have drivetrain drag contributing to the brake friction.
It does take longer to do it by disconnecting the halfshafts but the outcome is usually better for the shadetree. And it's not like you'll be doing this every couple of months. If you have a good parking brake assembly, you should have to do this only once. So your time is sort of like an investment in the outcome.
