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Discussion Starter #1
Alright the parking brake has defeated me:

2000 Sonoma 4WD with the rear disk brakes. It looks like the mechanism isn’t engaging the shoes enough to apply enough pressure for some reason. How can I differentiate between a problem at the wheel side (the lever or that area is worn and not actuating right) versus the pedal being somehow askew and not pulling enough on the cable. Pedal full down is barely holding.

I’ve replaced the shoes, both the left and right cables, and the hardware inside. I finally found the correct adjustment procedure (Haynes provides an incorrect procedure — I took everything off, loosed the equalizer, adjusted star until the shoe was barely not touching, then put everything back together and adjusted the equalizer until the shoe was barely not holding).

The only things I have yet to replace are the lever itself in the cab and the lever/wheel assembly that guides the lever.

What angle should the rear lever be at when the shoe is fully engaged? Is there some spec on how much travel I should see from off to applied on the inside cable?
 

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94 4x4,01 Blazer
2001 Blazer 4dr 4wd LT
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there is a adjustment on the cable itself- follow from cable back- the front cable bolts into the rear cable with an adjuster- lube and heat will be your helpers here- careful- it breaks easily.
 

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Been there Done it
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With rear discs it could be bad rotors.
The foot pedal usually either ratchets or it doesn't. Nothing to wear there.
 

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Discussion Starter #4
ok I’m told by my auto parts store friend that I may need to adjust more aggressively. If the rotors are bad, I assume they would be worn more towards the inside, right? The rotors are dirt cheap on rock auto so might be worth a shot. Is there a wear bit on the axle where the lever pushes against?
 

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He's talking about the drum inside the rotor. There are little shoes inside, that is the parking brake, the calipers don't do anything when you engage the parking brake.
 

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Discussion Starter #6
He's talking about the drum inside the rotor. There are little shoes inside, that is the parking brake, the calipers don't do anything when you engage the parking brake.
Yeah I've replaced the shoes but to no avail. And I didn't see any particular abnormalities in the drum, unless the difference was somewhat subtle.
 

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Yeah I've replaced the shoes but to no avail. And I didn't see any particular abnormalities in the drum, unless the difference was somewhat subtle.
For the parking brakes that have the shoes inside of a drum that is part of the rear rotors, you also have to adjust the shoes themselves. This much like the self-adjusters on regular drum-brakes. There is a screw with wheel on it between the two ends of the bottom of the shoes. When I did mine, I would adjust the screw, reinstall the rotor/drum, pull on the cable to center the shoes, put on the wheel and spin it. I would do this until I got a bit of light rubbing and then I'd back off the wheel a tad.

I have attached the park-brake adjustment procedure from my 1999 Blazer service manual.
 

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Discussion Starter #8
For the parking brakes that have the shoes inside of a drum that is part of the rear rotors, you also have to adjust the shoes themselves. This much like the self-adjusters on regular drum-brakes. There is a screw with wheel on it between the two ends of the bottom of the shoes. When I did mine, I would adjust the screw, reinstall the rotor/drum, pull on the cable to center the shoes, put on the wheel and spin it. I would do this until I got a bit of light rubbing and then I'd back off the wheel a tad.

I have attached the park-brake adjustment procedure from my 1999 Blazer service manual.
I may have not adjusted the star nut out enough -- your manual says "Turn the adjuster nut clockwise to increase the diameter until the rear wheel will not rotate without excessive force in a forward direction." It doesn't say anything about backing it off afterwards. That's what the auto parts store man recommended -- let the thing wear into the right fit as you drive it a bit.

I'll re-adjust. I have a new foot lever on the way since the present one is exhibiting weird sticking behaviors. If that doesn't work I'll do the pads and rear rotors.
 

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I may have not adjusted the star nut out enough -- your manual says "Turn the adjuster nut clockwise to increase the diameter until the rear wheel will not rotate without excessive force in a forward direction." It doesn't say anything about backing it off afterwards. That's what the auto parts store man recommended -- let the thing wear into the right fit as you drive it a bit.

I'll re-adjust. I have a new foot lever on the way since the present one is exhibiting weird sticking behaviors. If that doesn't work I'll do the pads and rear rotors.
For the parking brakes that have the shoes inside of a drum that is part of the rear rotors, you also have to adjust the shoes themselves. This much like the self-adjusters on regular drum-brakes. There is a screw with wheel on it between the two ends of the bottom of the shoes. When I did mine, I would adjust the screw, reinstall the rotor/drum, pull on the cable to center the shoes, put on the wheel and spin it. I would do this until I got a bit of light rubbing and then I'd back off the wheel a tad.

I have attached the park-brake adjustment procedure from my 1999 Blazer service manual.
For the parking brakes that have the shoes inside of a drum that is part of the rear rotors, you also have to adjust the shoes themselves. This much like the self-adjusters on regular drum-brakes. There is a screw with wheel on it between the two ends of the bottom of the shoes. When I did mine, I would adjust the screw, reinstall the rotor/drum, pull on the cable to center the shoes, put on the wheel and spin it. I would do this until I got a bit of light rubbing and then I'd back off the wheel a tad.

I have attached the park-brake adjustment procedure from my 1999 Blazer service manual.
Thanks Christine_ID for the pdf
 

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Discussion Starter #10
I adjusted the parking brake out, replaced the rotors just for fun and it appears to hold but the pedal can still travel to the floor. Unfortunately one of the wheels was quite tight after the bolts got put on and got a bit warm and started smoking? Not sure if that's a "run her until it stops smoking and deal with the gas mileage decrease" situation. In theory the optimal adjustment for the wheels is one picometer short of applying pressure.

I fail to understand why this parking brake is such a nightmare I've sunk far too many hours into this. I'm wondering if something else is worn -- like the lever or the mounting point. There are thoroughly insufficient specifications and instructions in Haynes and the factory service manual for this vehicle.
 

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94 4x4,01 Blazer
2001 Blazer 4dr 4wd LT
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you are using a Hayes -that's your problem- as some on here say-it's only good for lining a bird cage.- ps if brakes still soft after all that- time to change the rubber lines- they will swell under pressure as they age till they fail(usually when 50 miles from the nearest paved surface,in a downpour or bizzard on a holiday weekend)
 

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Discussion Starter #12
you are using a Hayes -that's your problem- as some on here say-it's only good for lining a bird cage.- ps if brakes still soft after all that- time to change the rubber lines- they will swell under pressure as they age till they fail(usually when 50 miles from the nearest paved surface,in a downpour or bizzard on a holiday weekend)
Heh well I tried both hanes and the GM Workshop DVD and neither were totally sufficient.

I've replaced the rear parking brake cables and everything is traveling fine -- it just seems like it's traveling too far? Or potentially the travel isn't sufficient to fully apply the brakes.
 
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