C3 Parking Brake Adjustment

I need help in adjusting my parking brake on my 1969 vette. I have the service manual and the assembly manual. I followed the instructions in the assembly manual on page J191, adjusting the nut near the equalizer
to tighten the cable. The Parking brake holds better, but not like it used to. I can put the car in reverse and the brake holds with minimum acceleration. However, in first or second gear there is no hold with minimum acceleration. I'm afraid to tighten the nut any more unless it won't break something.
On page 5-23 of the service manual, another adjustment is indicated. I should tighten the "disc" adjustment screw (at least I think that's what it is). Now the picture in the service manual shows one hole, but there are a number of holes on my disc. According to the manual's directions, one should turn the disc until the adjusting screw is seen through the hole. I've turned my disc and I don't see a screw.
Here are my questions:
1. Is there a screw for tightening the disc that can be found through one of the holes on the disc? If so, how do I find it?
2. Do I need to tighten this screw as part of making the parking brake hold better?
3. Is there any danger to continuing to tighten the cable? If this is the way to tighten the cable, I will continue to see if I can make the brake hold better with very minor acceleration.
Please get back to me with comments as soon as you can. I need to get an inspection sticker, and the parking brake is checked as part of the inspection. The inspector accelerates very slightly and expects the brake to hold.
Thanks, Charles
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Yes this is what you need to find to properly adjust the p-brakes. You access the "screw" through a hole in the hub area of the disk - the same surface where the wheel studs are located. Raise both rear wheels off the ground and remove them. With the car in neutral, rotate each disk so that the empty hole (no stud) is at the bottom and closest to the ground - you may be able to peer into it to see the "screw" - which is not really a screw but a star-wheel (kinda like a gear - you'll only be able to see the teeth - like looking at a gear's edge). The screw driver is used to catch the teeth and push them upwards or downwards to adjust the brakes. By rotating the star-wheel, you are in effect, changing the length of a spacer between the p-brake shoes.
Look in your service manual to see if there's an exploded parts view for overhauling the brakes - you'll see the star-wheel in the lower portion of the diagram and how it sits between the p-brake shoes.
Here's the procedure for adjustment: 1) after removing the wheels - you did use jackstands to support the car, yes? - with the hand brake released, loosen the cable nut you tightened earlier, to the point that there's plenty of slack and no tension on the cables.
2) working on one side at a time, tighten the star-wheels until you can't rotate the brake disk and then back off the star-wheel 6-8 notches.
3) set the handbrake lever 2 or 3 clicks and then tighten the cable nut to take up the slack plus a quarter turn more. Rotate the hubs - you should just feel slight drag. When you release the hand lever, you shouldn't feel any drag at all.
Viola!

Yes.

Yes - you could snap the cable. It's used only to make minor adjustments - if the shoes are worn or not adjusted properly, it's not the way to go about making them work better.
Here's waving to ya - \||||
Owen ___
'67BB & '72BB
-- not affiliated with JLA forum in any way -- alt.autos.corvette is original posting -- ___
"To know the world intimately is the beginning of caring." -- Ann Hayman Zwinger
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In article

I just wanted to clarify that the access hole is not on the outer edge of the disk - these are cooling spaces - but located near the center of the disk on the same surface where the wheel mounts.
Here's waving to ya - \||||
Owen ___
'67BB & '72BB
-- not affiliated with JLA forum in any way -- alt.autos.corvette is original posting -- ___
"To know the world intimately is the beginning of caring." -- Ann Hayman Zwinger
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Barking Rats,
I went out and looked. Except for the five holes between the studs and a center hole, there are no more holes.
1. Am I suppose to see the adjusting screw through one of those holes? If so, I don't see it.
2. Also, can I do one wheel at a time, or do I have to rotate one wheel, then the other, then look for the screw?
Thanks, Charles
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I believe I know what's going on. From the factory, the rotor is held to the axle hub with rivets. These need to be drilled out to remove the rotor, which I believe has been done in the past on your car and that's why you see 5 holes (I think there are only 4 rivets). When the rotor was put back on the hub, the service person didn't replace the rotor so the access hole in it lined up with the access hole in the hub.
In order to do the job properly, you'll need to pull the calipers off the rotor (pull the center pin from the pads and use a large socket to keep the pads apart so they don't close up when the caliper is free of the rotor). Pull off the disk -- and as long as the disk is off, inspect the parking brake pads and hardware -- make note of the star wheel adjuster so you know what action is happening when it's all put back together and you're back to making the adjustments. Align the access hole in the rotor with the access hole in the hub.
Yes, you adjust one wheel at a time, but both need to be in the air so you can freely rotate the side you're working on to feel for any drag.
Here's waving to ya - \||||
Owen ___
'67BB & '72BB
-- not affiliated with JLA forum in any way -- alt.autos.corvette is original posting -- ___
"To know the world intimately is the beginning of caring." -- Ann Hayman Zwinger
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Owen probably hit the nail on his description of the problem. Your rotor should look like this.
http://i7.ebayimg.com/01/i/05/32/b2/f4_1.JPG
You notice there are two extra holes slightly outside the circle of the lug holes. Those should line up with the holes in the spindle hub so that you can reach the adjuster on the emergency brake.
You can see the holes in the spindle in this shot.
http://i10.ebayimg.com/02/i/04/94/8c/00_1_b.JPG
There is the possibility that someone stuck a front rotor on, as some front rotors do not have the adjuster hole in their top hat. If that is the case, you will need to get rear rotors and adjust, or simply adjust with the rotor off and hope you get it right.

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--
Dad
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Truthfully, I had never thought about it before. In fact, I hadn't even noticed if the holes were different, but while searching for some pictures, I found some front rotor pictures and they didn't have the adjuster hole.
So it is always possible that Chevy actually did a front and a rear rotor. I would have thought it more efficient to run one line doing all rotors the same, rather than have one different.
Of course, what it meant was that one line omitted the inner brake surface machining and the two extra holes.
I should look that up.
65-82 3996663 (3996683?) 2 req 162.00 Disc, RR brk (fin) 65-68 3998278 2 req 179.00 Hub, w/disc, frt 69-82 3991024 2 req 180.00 Hub, w/disc, frt
The front disc were apparently only available riveted to the front hub as a service part. The rear was without the spindle as a service part. Those are Dec. 1983 prices, no idea what they are today.
I'd have to find some front disc and find if they were machined inside or not. Never thought about it before.
The ones on the race cars were unriveted so they were loose, but then there were no emergency brakes either, so it was never an issue.
Learn something every day, don't we? If someone doesn't come up with a front and rear to compare, I'm going to have to find some just to get to the bottom of this.

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https://www.rockauto.com/ at some of their prices and they have pictures of the items. I actually thought that the rotors on the rear were smaller than the front. They have been a God send for a number of old parts for my Mustang, Corvette, and the Chevy coupe. In allot of cases their prices are a third of the auto stores. They are mostly US made parts, helpful phone service, reasonable shipping, and fast. I replaced all 4 drums, shoes, spring kits, and seals for what a Mustang store wanted for 2 drums, all Raybestos. By the way the '65 Mustang had 3 different brake drums that year and what I got was spot on, both the parts and the information on their site.
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My '79 parts book shows the same. Any idea what change took place between '68 and '69? Could it be an offset thing owing to the wider wheels in '69?
Here's waving to ya - \||||
Owen ___
'67BB & '72BB
-- not affiliated with JLA forum in any way -- alt.autos.corvette is original posting -- ___
"To know the world intimately is the beginning of caring." -- Ann Hayman Zwinger
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The spindle, bearings, and hub are all different on '68 from '69. '68 still ran the smaller one like the '65-67. There was a difference in the '68 spindle from the '67, though. I think they changed the bolt sizes on the steering arms in '68 and again in '69, but that doesn't affect the hub size.
wrote:

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'I need help in adjusting my parking brake on my 1969 vette'
REPLY: On my 1970, i had two seasoned Vette Mechanics adjust the parking brake ; both times the parking brake dragged afterward. The first time, i immediately went on a 8 hour trip and averaged 10 mpg while smelling the heat from the brakes. So...after you get it adjusted, recheck it to be sure they arent dragging. I dont know why both mechanics couldnt get it adjusted correctly ; I ended up not having a parking brake that engages after all that because i told the last mechanic to just put it back to how i brought it in.
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snipped-for-privacy@webtv.net (dave) wrote:

I suspect your p-brakes may have been in need of a rebuild - as in replacing all the springs and mounting pins. They get rusty, heat stressed and just worn out - plus the lube on the rub spots and pivot points dries out and can get gummy.
Here's waving to ya - \||||
Owen ___
'67BB & '72BB
-- not affiliated with JLA forum in any way -- alt.autos.corvette is original posting -- ___
"To know the world intimately is the beginning of caring." -- Ann Hayman Zwinger
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'I suspect your p-brakes may have been in need of a rebuild - as in replacing all the springs and mounting pins. They get rusty, heat stressed and just worn out - plus the lube on the rub spots and pivot points dries out and can get gummy. Here's waving to ya - \|||| Owen'
REPLY: That could very well be. In any case, i dont really have a need for a Parking Brake ; i just leave it in gear when i park.
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snipped-for-privacy@webtv.net (dave) wrote:

I did that once when I parked in a friend's steep driveway in a '65, 4-speed. Came out of his house to find my car at the bottom of his drive - it appears gravity overcame inertia and engine compression.
Here's waving to ya - \||||
Owen ___
'67BB & '72BB
-- not affiliated with JLA forum in any way -- alt.autos.corvette is original posting -- ___
"To know the world intimately is the beginning of caring." -- Ann Hayman Zwinger
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'I did that once when I parked in a friend's steep driveway in a '65, 4-speed. Came out of his house to find my car at the bottom of his drive - it appears gravity overcame inertia and engine compression. Here's waving to ya - \|||| Owen '
REPLY: Thanks for the heads up ; Ill stay on fairly level ground.
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(dave) wrote:

I guess I misunderstood the term "seasoned mechanic" all these years. So I now understand that it is a mechanic that lets a car out on the road with the emergency brake on so it can burn them out???? Then to he might just leave something loose or un-connected so the brakes don't work at all along the way. Most of the time when a "seasoned mechanic" has worked on my car I don't feel the need to check his work. If smelling the brakes for 8 hours doesn't tell you something, checking his work would confuse you even more.
My guess would be that the "seasoned mechanic" was made up to make dave's story sound better. On the other hand I consider myself a "seasoned mechanic", (heavily salted), that on his worst day could do something that stupid but I don't remember any right now.
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Interestingly, at least to me, was what I found when reviewing my '72 Chebylay Passenger Car Service Manual, page 5-42, under Corvette Brakes, "Parking Brake Shoes": ___ BURNISHING NEW LININGS (Parking Brake)
NOTE: When replacing the parking brake shoes, it is necessary to "break in" the new shoes in the following manner. (Brakes should be adjusted before beginning.) 1) With vehicle traveling at 50 mph, apply the parking brake until light drag is felt (10-12 notches). 2) Operate the vehicle at this speed for 50-60 seconds with brake applied as in Step 1. 3) Return the brake handle to the released position. ___
Also a note to Charles: This source says to adjust the cables with the handle set at 13 notches while the source I mentioned before specified 2-3 notches. Maybe aim for 6-8 notches to make sure the brakes are fully released when the handle is released.
Here's waving to ya - \||||
Owen ___
'67BB & '72BB
-- not affiliated with JLA forum in any way -- alt.autos.corvette is original posting -- ___
"To know the world intimately is the beginning of caring." -- Ann Hayman Zwinger
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There was a time that they wanted the O.D. of the shoes cut to the I.D. of the drum which may be a mote point now that one cleanup on the drum cut will scrap the entire disk/drum.
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'My guess would be that the "seasoned mechanic" was made up to make dave's story sound better'
REPLY: No..it wasnt made up. The first mechanic owned a Corvette Shop and had been in the business for over 35 years. The second one was at a large local Chevy Dealership who worked on nothing but Corvettes for his employer . The trouble is, they both lost their 'seasoning' somewhere along the way. I still may get the parking brake fixed IF i can find a more seasoned mechanic that the two i went to .
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