Author Topic: No slot on rear backing plates  (Read 3070 times)

camaronut

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No slot on rear backing plates
« on: May 05, 2020, 02:59:33 PM »
Wanted to adjust the parking brakes on my 69 SS.  Went underneath and noticed there weren’t any slots to gain access to the adjusting wheel inside the drum.  I didn’t see any knockouts but maybe I wasn’t looking hard hard enough.  I would think there would be a rubber plug to remove to gain access, but nothing.  Did 12 bolt rears not have these holes/access slots???

Dusk Blue Z

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Re: No slot on rear backing plates
« Reply #1 on: May 05, 2020, 04:40:04 PM »
The stock knock outs are through the drums.
Mike

1969 Z/28 Legends Certified
1969 Z-10 Under Construction

camaronut

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Re: No slot on rear backing plates
« Reply #2 on: May 05, 2020, 10:05:24 PM »
Thanks Mike... I’ll check.

What happens with the holes, is there a rubber plug that goes in it’s place???

bertfam

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Re: No slot on rear backing plates
« Reply #3 on: May 06, 2020, 12:23:36 AM »
Adjusting drum brakes on the Camaro isn't required. They're self adjusting. If you replace the shoes, you just adjust the star wheel until there's just a hint of drag on the drum when you put it back on, then drive forward and reverse several times so they adjust themselves.

There WAS a GM part number for the "cover" (P/N 1455658), but it was used on cars built up to 1964 (cars without self adjusting brakes). Note that this "cover" was metal and snapped into place. P/N 1455658 was superseded by P/N 5464803 in 1979 and was a generic part for all GM cars and trucks, but was never installed at the factory. This was a rubber (then later plastic) plug that pushed into the hole.

As for adjusting the parking brake, once the rear shoes are adjusted correctly, the parking brake is adjusted via the equalizer on the cable. All this is in the CHASSIS SERVICE MANUAL, Section 5 (Brakes), starting on page 5-7.

Ed

camaronut

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Re: No slot on rear backing plates
« Reply #4 on: May 06, 2020, 01:34:31 AM »
Awesome info Ed......as usual!!!

Thanks!

Dusk Blue Z

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Re: No slot on rear backing plates
« Reply #5 on: May 06, 2020, 12:04:00 PM »
Usually not a problem adjusting them, but unadjusting, when you want to get the drums off.
Mike

1969 Z/28 Legends Certified
1969 Z-10 Under Construction

bertfam

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Re: No slot on rear backing plates
« Reply #6 on: May 06, 2020, 01:36:01 PM »
The service manual states to loosen the parking brake cable at the equalizer then remove the drum. That's always worked for me.

Ed