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Parking Brake - self adjusting assembly?

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Old July 12th, 2024, 3:08 PM
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Default Parking Brake - self adjusting assembly?

I see references to the parking brake cable being self adjusting at the pedal.

In the manual it only looks like this auto-adjust it for putting slack in the cable for service to the brakes or cables.

But ... I see a small lever attached to the parking brake assembly and found one reference to it having to do with the self adjusting mechanism. I find nothing in my maintenance manual about it.

Have you encountered the lever or can you educate me on the "auto-adjust"?
Old July 12th, 2024, 8:53 PM
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I'm not sure about the cable, but back in the day of drum brakes, the parking brake mechanism is supposed to self adjust *in theory*. I believe hitting the brakes while driving in reverse is what ratchets it tighter. Of course as the parts wear and get rusty the self adjustments becomes less reliable. It's good to manually adjust yourself once in a while.

Last edited by mountainmanjoe; July 12th, 2024 at 8:54 PM.
Old July 13th, 2024, 7:03 AM
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Almost every car or truck I've driven over the past 44 years of driving has had drum brakes in the rear, and I've always done my own brakes. I think the only vehicles I ever owned with rear disc brakes were a Subaru and a Volvo.

As @mountainmanjoe mentions, there is the self adjuster mechanism that is part of the rear brake mechanism. I'm closely intimate with this as I did the rear brakes on my 2006 Silverado 1500 last weekend. It effectively ratchets out every time you hit the brakes, to ensure that the brakes are almost flush against the surface of the drum. When you do the brakes, you turn it all the way in, then work it back out until the drum fits fairly snug and just turns.

The emergency brake system engages with one of the two brake shoes via a cable and a lever that is attached to one of the shoes in each drum. On my truck, there is a single cable from the emergency brake pedal, to about halfway back on the frame, and at that point, it has a bracket that the cables to the two rear wheels. I detached the cables from that bracket to get enough slack in them to remove and replace the brake shoes, then reattached. I am thinking maybe you have a lever to release the cable from the pedal itself, to get slack, or else to attach it in the first place. Either way, I've never looked for or used a lever on the emergency brake pedal, so I would leave that alone. No self adjusting of the brake mechanism is happening at that pedal.

Last edited by jfmorris; July 13th, 2024 at 7:04 AM.
Old July 13th, 2024, 8:59 AM
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Default Only e-brake is a drum brake ...

Originally Posted by jfmorris
Almost every car or truck I've driven over the past 44 years of driving has had drum brakes in the rear, and I've always done my own brakes. ...

As @mountainmanjoe mentions, there is the self adjuster mechanism that is part of the rear brake mechanism. .... It effectively ratchets out every time you hit the brakes, ...

.... I am thinking maybe you have a lever to release the cable from the pedal itself, to get slack, or else to attach it in the first place. Either way, I've never looked for or used a lever on the emergency brake pedal, so I would leave that alone. No self adjusting of the brake mechanism is happening at that pedal.
-------------
The '03 Express 3500 has disc brakes all around. Only the emergency brake is a drum brake. I have worked on the van's disc brakes myself ... and on my Volvo.

So if driving in reverse and hitting the disc brakes is supposed to tighten the emergency brake that is an independent system ... what is moving what?
Or does "hitting the brakes" mean "apply the parking brake" while driving in reverse?

All the auto-adjust in the manual refers to the e-brake pedal. Pg 5-138.

Last edited by tbb2; July 13th, 2024 at 9:03 AM.
Old July 13th, 2024, 8:03 PM
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https://charm.li/Chevy%20Truck/2003/...rake%20System/
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Old July 14th, 2024, 8:14 AM
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Originally Posted by tbb2
-------------
The '03 Express 3500 has disc brakes all around. Only the emergency brake is a drum brake. I have worked on the van's disc brakes myself ... and on my Volvo.

So if driving in reverse and hitting the disc brakes is supposed to tighten the emergency brake that is an independent system ... what is moving what?
Or does "hitting the brakes" mean "apply the parking brake" while driving in reverse?

All the auto-adjust in the manual refers to the e-brake pedal. Pg 5-138.
Ok - ignore my original post if this has rear discs. I was assuming it was like all the GM trucks I've owned which had rear drums. I had one vehicle now that I recall that had rear discs and there was a small drum type assembly for the parking brake back there, but you are right - no auto-adjusting is going to take place when hitting the regular brake pedal. Only the emergency brake pedal is going to affect it.
Old July 14th, 2024, 8:17 AM
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Originally Posted by mountainmanjoe
I think the parking brake cable auto-adjuster in this manual is what the original poster is seeing? This link should take care of the questions...
Old July 21st, 2024, 10:01 AM
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Default auto-adjust ... not that I can see

Well I finally recruited someone to help and went through the motions of disabling and enabling the brake cable auto-adjuster.
Unless the "auto-adjuster" is broken it is just a cable lock to put slack in the brake cable while working on the cables.
I do not see anything that qualifies as an adjustment. There is no increase in tension.

I still do not see or understand the purpose of the small lever. It just moves with the parking brake. (?)

I have yet to find anything in the manual that specifies the length of the various cables to check for stretching.
The thought that the cable apples more or less pressure on the e-brake may just be a misdirection and
all the adjustment is in the rotor itself through the port on the axil side of the wheel.

Last edited by tbb2; July 21st, 2024 at 10:04 AM.
Old July 22nd, 2024, 1:24 AM
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parking brake adjustment is covered in the section titled "Park Brake Shoe - Replacement"
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