Parking brake problem

gica

Original poster
Member
Dec 25, 2012
135
Cali
I have a quick question about the parking brakes. I just changed them since one side were completely broken off the horse shoe looking deal and am trying to adjust, I already opened it 3 times to adjust the star looking nut and I already have 3/16 out on one side and 1/4 on the other, and still it doesn't completely stop it going forward, reverse is great it holds but the forward it still allows movement. What is that all about? Is there another adjustment that I am not aware off?
 

Mooseman

Moderator
Dec 4, 2011
25,671
Ottawa, ON
Did you alternate the shoe length from one side to another? In old drum brake systems, you had one shoe shorter that you always put in the forward position and you knew when you put the wrong shoe in front as it would lock up. You have to switch one of the shoes so the long shoe is forward so that one would grab forward and the other backwards.
 
Dec 5, 2011
578
Central Pennsylvania
This platform doesn't have "old school" drum brake shoes.... the parking brake shoe is a single piece per side. I have had one hell of a time getting mine to even attempt to stop my car. It is entirely possible that the inner diameter of the drum is out of spec... but let's try some other things first.

Before working on the parking brake, there is a little "button" at the bottom of the brake lever that you need to push. This releases any pre-tension on the brake cable. The parking brake cable is self-adjusting and the lever will constantly try to take out slack. Pressing this button will release the pre-tension. This will become important later.

When I change my parking brake shoes I usually knock off the lip that forms on the lip of the drum. Sometimes it takes some grinding with a stone, but usually just hitting it with a scraper/putty knife will do the trick (Wear at least a dust mask if you do any grinding whatsoever). It's usually just rust and comes right off. Then I CLEAN the inside of the drum VERY WELL, including using brake cleaner.... then when reinstalling the drum back on the axle, I usually adjust the star nut ("adjuster" technically) so that the drum barely clears the shoe. If you're installing a brand new shoe after removing a worn or broken one you will likely need to rotate the adjuster to make it smaller instead of larger - regardless, you want the drum to just barely clear the shoe, without dragging. While you have the drum off, if you look behind the adjuster, there should be a knockout you can punch out (if it's not already knocked out). You can actually turn the adjuster with the drum installed if this knockout is removed. I haven't removed mine on my current Bravada, but had to on my wife's. Once the drum is installed (barely clearing the shoe), pull the brake handle, let it set, and release it several times. This should take out any slack in the cable. You may choose to completely reinstall everything before doing this. After everything is reinstalled, and you've pulled the brake handle several times, you an check your parking brake for effectiveness. I usually do this by putting the car in drive, setting the brake, and easing off the brake pedal. If it holds, yahtzee, if not, the adjuster needs some work. Rinse & repeat. Pressing that pretension release button may or may not be necessary on subsequent R&R of the drum.

If you absolutely cannot get the parking brakes to "grab", your drum is very likely out of spec - there may be no good way to get them to grab without replacing the drum. Brakemotive is a decent brand option for replacements.

Some words of caution.... I NEVER jack up a car and remove the wheels without putting the wheels under the frame... NEVER spray brake cleaner on HOT parts, bad gases can form. Safety glasses are always a good idea... always. Whenever you work with one or more of the back wheels removed, CHOCK THE FRONT WHEELS. And there's never a bad time to check your brake fluid except while in motion - that's kinda hard to do.

ALSO... I usually spray out the backing plate (what all the brake hardware mounts to) with brake cleaner. You'll almost never get it "clean" but you want to try and knock as much of the crud off as possible. Proper and judicious use of a good brake-rated synthetic grease on SLIDING brake parts can save you headaches down the road (apply a tiny amount on the adjuster's threads). If you find GEAR OIL brake drum REPLACE the axle seal, or you will regret it.... possibly VERY BADLY. Grease/Oil and brake parts are a bad combination. When in doubt, buy double the brake cleaner you were going to... AND USE IT. I usually buy 1 can per wheel, plus 1 can.
 
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gica

Original poster
Member
Dec 25, 2012
135
Cali
Ok so I opened it again and removed everything at the hub. I then released the tension at the inside handle/lever. there is a spring loaded multiplier lever and as soon as you pull on it you can hear a release. I make sure I do that with the handle as close to down position as possible. Then I lower it all the way. At the hub you have to put the brake shoe inside the hub and see that it fit pretty close to the diameter. Then you install the little star wheel and adjust it to open based on the size of the shoe opening and twist it a few times more. You will notice that the gap is not the same on both sides. Passenger for me was way wider so I had to open the wheel probably a bit more than 1/4. The other side was probably a bit more than 3/16. I loaded the hubs is lug nut to secure and went inside the car to pull the hand brake handle up and down 3 times to tighten the spring loaded system underneath. It basically tightened the brakes all the way. Mounted everything back without releasing the hand brake. So at first with the brakes still on the car would not move in forward and reverse I mean dead still. As soon as I released the hand brake and reapplied it does tighten the brakes but the forward is not dead still. You cannot use this to block the wheels while driving, maybe for reverse it may work as you cannot move the car when giving it gas. So that is it I don't know why it is so weak on holding while in drive but reverse is great and I mostly need that for boat launching, so I don't force clunking while in park. I think either the handle mechanism is not good enough to hold the tension or at the hub the lever that is being pulled by the cable might have play, slimmer chance for that. So I think the problem is at the brake handle mechanism.
 

Mooseman

Moderator
Dec 4, 2011
25,671
Ottawa, ON
The way I usually adjust it is to pull the disc/drum, turn the adjustment wheel a little, put the drum back on, apply the brake the re-center the shoe, release and check for drag. Keep repeating this until you start feeling a little drag and the handle doesn't move up too much to engage it.

That little adjustment lever in the handle is useless to do anything with because it is depressed each time the lever is brought down so it is continuously adjusting itself.

It is important to ensure that you alternated the brake lining length on each side. As you can see in this pic, the shoe linings are of different lengths on the same shoe. One side you should have the short lining in front and the other side the long one.

410%2BkqwyqtL.jpg
 

gica

Original poster
Member
Dec 25, 2012
135
Cali
So I wanted to run this by the participants here, I replaced my parking brake horse shoes and I opened them back up 4 times to find a proper way to adjust. The problem is that the forward stopping is not so good so the 4th time I opened it after reading the proper procedure to adjust and adding my own 2 cents to it. I removed all the parts from the rear wheels including the levers that are pulled by the cables on both sides to see what's up. Then I released the tension at the handle by lifting it very little to allow access to a little lever underneath, pull that lever until you hear, or feel a release happen. Lower the handle back all the way. I then placed the shoe right inside the hub to check clearance and it was pretty close. I then placed the ring on each side and visually checked how much I had to spin the adjustment to get the shoe to fit leveled and turned it a bit more. Mounted it properly with the groove on the star side vertical and the other side horizontal, I then placed the hubs in and I have to mention the passenger side adjustment was turned about 1/8 more than the driver side so not the same. Again it has to be visually assessed when installing the shoe, pretty obvious. After I pushed the hubs all the way I used 2 lug nuts on each side to secure the hub is in. Went inside and pulled the handle up and down 3 times and left it engaged. Removed the lug nuts and place the security washers(or what ever they are called) install the rest of the stuff and wheels and torqued everything right. So in the car I started engine and placed in drive car doesn't move forward(great0 place in reverse same deal so I lower the handle and engage again and it is not as good as it was before. Shit, in forward gear it still rolls but not as bad as the other 3 times I adjusted, reverse is fully secured though, so when I launce the boat I am in good shape with this but the forward doesn't want to grab it 100%, why is this? My opinion is either the release mechanism underneath the handle doesn't tighten properly, or the lever adjustment mechanism at the hub is loose and doesn't push the cylindrical SS pin far enough to lock the wheel or the engineering behind this emergency brake mechanism is faulty and in the 8 years they build this car they didn't remedy it. Who knows but that's my story on the e-brake adjustment. Taking opinions, as now it takes me less than 5 minutes to remove the hubs, and that's both sides. Hahaha
 
Dec 5, 2011
578
Central Pennsylvania
The way I usually adjust it is to pull the disc/drum, turn the adjustment wheel a little, put the drum back on, apply the brake the re-center the shoe, release and check for drag. Keep repeating this until you start feeling a little drag and the handle doesn't move up too much to engage it.
That little adjustment lever in the handle is useless to do anything with because it is depressed each time the lever is brought down so it is continuously adjusting itself.
That..... that would be news to me..... but.... I have been very, very wrong before...
It is important to ensure that you alternated the brake lining length on each side. As you can see in this pic, the shoe linings are of different lengths on the same shoe. One side you should have the short lining in front and the other side the long one.

410%2BkqwyqtL.jpg
And on this point.... I, uh... I would be wrong, again.... Looks like I need to pull the rear wheels tomorrow and double/triple check.... this might explain a lot.
 

gica

Original poster
Member
Dec 25, 2012
135
Cali
Wow I just discovered my own thread, and the volume of info here. I was still on the old thread which got closed, posted on the wrong one my bad.
So I have to figure out which is the short side or long side for forward and reverse locking.
Looking at the 2 shoes above I really cannot tell what is what. I see the 2 holes are at different ends in each shoe. The lining on the 2 shoes is different? What about the shoes are they 2 different size? And the ends where it attaches to the lever ends mechanisms does it matter which end is which? I probably have to open the damn thing again and have a look at the actual shoes to realize what what said here.
 

Mooseman

Moderator
Dec 4, 2011
25,671
Ottawa, ON
Yeah, you will see on each shoe there is one long and one short lining. You'll figure it out.

I had discovered this quite by accident. I had replaced the parking brake on my 9-7x when I first bought it and they never really worked well, like yours. I used the old saying "short shoe forward" from the days of old drum brakes. Then I blew the differential and replaced it with a low mileage one. When I took the brakes on that diff apart, I noticed this long and short lining thing when the long was in front on one side while the other side had the short one forward so I figured that's the way the factory put them. When I used it the first time while rolling, it actually locked up the wheel.
 

gica

Original poster
Member
Dec 25, 2012
135
Cali
So it doesn't matter which side(passenger/driver) has long towards the front as long as the other side is long towards the back short forward?
 

Mooseman

Moderator
Dec 4, 2011
25,671
Ottawa, ON
I would think so. If my very faint memory serves me right, the right side had the long lining forward.
 

gica

Original poster
Member
Dec 25, 2012
135
Cali
So I opened it yet again and this time I compared the 2 shoes and the are identical, the difference is where the 2 holes go so if to turn it there should be a difference. In my case not much I get really good reverse lock but no lock forward. So in all probability the hubs need replacement.
BrakeRear1.jpg
This is how far out the adjustment is on passenger side. And the adjustment not to expand the arch just to reach the normal arch of the shoe.
The driver side is about 1/8 less.
Brakes2.jpg
This is the passenger side with the 2 holes toward the back so I guess that makes the long side forward, whatever that means. The driver side is opposite.
Again the brakes are fine for my needs to hold the car and boat at launch at an incline.
So reverse are good.
 

Mooseman

Moderator
Dec 4, 2011
25,671
Ottawa, ON
Yeah, that is out quite a bit. The drum inside the hat shouldn't really wear since it's not being used like the regular service brake, if that's what you mean by "hub". Just be sure you have them adjusted as far out as possible, like I explained, with just the slightest drag. Also rust can accumulate on the drum since it's not used so much and is not used while moving, which might not help. They'd almost have to make those inner drums out of stainless.

Personally, I hate these drum-in-hat parking brake systems. Small, ineffective and more troublesome than they're worth. I really loved the ones in our Montana van which would use the same disk and pads pushing the piston out using a screw.
 

gica

Original poster
Member
Dec 25, 2012
135
Cali
Yes I do have the rust and I did sand it as much as possible. But it almost seems like mechanism on the passenger side is shorter than the other, otherwise there would be no need to open it so much as the shoes are identical, and so are the discs. So it would have to be the actual cylinder where the adjustment star bolt goes into.
 

Mooseman

Moderator
Dec 4, 2011
25,671
Ottawa, ON
Did you look at them come out when you pulled the lever with the rotors off? I think you did mention you made sure the small metal "pills" were inside the star wheels. With everything together, does the lever go up a lot before you get full resistance? it should pretty much stop about half way.
 

gica

Original poster
Member
Dec 25, 2012
135
Cali
Yes when I pulled the discs out I did pull the brake handle and it popped out the side that didn't have the adjuster star.
The handle doesn't stop half way. It starts building pressure half way and then at the end it sort of feels like all of a sudden there is extra leverage available. I remember if I adjust out the driver side where it is almost impossible to push the disc in , then it tighten half way. There is definitely something wrong, between the 2 sides.
Still the passenger side is way off, and as I said just to be on par with the shoe opening, and slide the shoe in, without expanding the gap at all, I have to move the adjustment out at least 3/16 maybe 1/4.
I have had the car since it had 19k miles and mostly used it to pull my 20 footer boat around, just recently started driving it daily. I have 84k miles in 15 years, 65k are mine.
I bought this because it was the cheapest SUV with lower mileage that I could find. And I knew the Chevy tranny was great, asked a tranny shop about it.
 

gica

Original poster
Member
Dec 25, 2012
135
Cali
I just ordered the rear rotors, AC Delco Silver, and pads will see how that goes.
 

gica

Original poster
Member
Dec 25, 2012
135
Cali
I replaced the front and rear rotors and pads and the hand brake is as worthless as ever. So it wasn't the rust it's just bad design.
 

Tankcruiser

Member
Oct 29, 2018
108
Toledo
possible cables stretxhed out or uneven? look for where 2 cables comes together with single from lever
should be about even parallel... thats what i did on mine but didnt replace cables just chiming in my thing
 

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