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Old 05-30-2020, 11:29 PM   #1
402Bowtie
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HO52 Rear Drum Brakes Adjustment Hole Exists

There are few old threads that people mention having difficulty adjusting the drum brakes on HO52 rear drums. Like many others, I was hoping to find an access hole on the backside that some other drum brake models have for adjusting the star wheel. But the drums on my 72 don't have any access holes on the backside.

From what I have read it seems like many (maybe all) HO52 drums do not have an access hole on the backside of the drum. However, today, after replacing the shoes and guts, I noticed that my 72 does have an access hole on the front of the drum.

Do others have this this hole? Is this common knowledge? I feel like I haven't seen much mention of this hole in the past.
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Old 05-30-2020, 11:59 PM   #2
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Re: HO52 Rear Drum Brakes Adjustment Hole Exists

I'm glad (and you are lucky) that your drums have that access hole. Mine definitely do not.
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Old 05-31-2020, 12:45 AM   #3
FirstOwner69
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Re: HO52 Rear Drum Brakes Adjustment Hole Exists

Mine do, and they are the orginals.
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Old 06-30-2020, 03:00 PM   #4
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Re: HO52 Rear Drum Brakes Adjustment Hole Exists

Just got new drums for my C20, the drums did NOT come with Adjuster holes, Looks like one of the original drums someone cut and drilled the adjuster hole.
Is it OK to cut and Drill the Drum for the Adjuster Hole??
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Old 06-30-2020, 03:14 PM   #5
402Bowtie
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Re: HO52 Rear Drum Brakes Adjustment Hole Exists

Quote:
Originally Posted by Astro-Balls View Post
Just got new drums for my C20, the drums did NOT come with Adjuster holes, Looks like one of the original drums someone cut and drilled the adjuster hole.
Is it OK to cut and Drill the Drum for the Adjuster Hole??
I know others have drilled the hole.

The kit I used to replace my drum parts included a few types of plugs...You might consider drilling the hole in a way that you can plug it with something.
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Old 06-30-2020, 04:01 PM   #6
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Re: HO52 Rear Drum Brakes Adjustment Hole Exists

Quote:
Originally Posted by Astro-Balls View Post
Just got new drums for my C20, the drums did NOT come with Adjuster holes, Looks like one of the original drums someone cut and drilled the adjuster hole.
Is it OK to cut and Drill the Drum for the Adjuster Hole??
personally I'd drill a hole in the backing plate so you can adjust with the wheel on. I haven't looked at one of those in a while but it should be possible.
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Old 06-30-2020, 04:09 PM   #7
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Re: HO52 Rear Drum Brakes Adjustment Hole Exists

Quote:
Originally Posted by Astro-Balls View Post
Just got new drums for my C20, the drums did NOT come with Adjuster holes, Looks like one of the original drums someone cut and drilled the adjuster hole.
Is it OK to cut and Drill the Drum for the Adjuster Hole??
I have new Raybesto, and Centric and Wagner stuff laying around most of them do not have the holes, but its in the stamping, or casting.

I wonder if you hit those with a drift pin of some kind do they pop out?

Thinking this is a possibility, knowing manufacturing they would call it non value added processing. And collect the same money for the part.
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Old 06-30-2020, 04:33 PM   #8
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Re: HO52 Rear Drum Brakes Adjustment Hole Exists

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Originally Posted by toolboxchev View Post
I have new Raybesto, and Centric and Wagner stuff laying around most of them do not have the holes, but its in the stamping, or casting.

I wonder if you hit those with a drift pin of some kind do they pop out?

Thinking this is a possibility, knowing manufacturing they would call it non value added processing. And collect the same money for the part.

I have found that trying to punch them out does not work. All you do is beat the crap out of the drum.

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Old 06-30-2020, 04:38 PM   #9
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Re: HO52 Rear Drum Brakes Adjustment Hole Exists

Quote:
Originally Posted by toolboxchev View Post
I have new Raybesto, and Centric and Wagner stuff laying around most of them do not have the holes, but its in the stamping, or casting.

I wonder if you hit those with a drift pin of some kind do they pop out?

Thinking this is a possibility, knowing manufacturing they would call it non value added processing. And collect the same money for the part.
I recently went through the rear brakes on my 69 CST 20. Still had the original GM drums. After some careful probing I was able to find the knock out location for the brake adjustment. While it looks like a simple knock out these would not come out easily. Had to heat the knockout area with a torch then punch it through. Upon removal I found both original drums to be junk so they were replaced with the only new drums I could find: Centric brand from rock auto. These do not have knockout holes, I made my own patterning the originals.

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