Brake drum adjusting hole cover

[Goldie Driver]

The holes in the drum work as you describe @Goldie Driver, providing access to the adjuster. It was the plugged holes in the backing plate I was referring too. Maybe they allowed you to check brake some wear?

I have never seen a GM backing plate with the adjusting hole. My Ram Chargers had them. I wonder if someone put a different backing plate on ? Some modern cars have little inspection plugs for lining wear on the back brakes so maybe you are on to something there.

Got pics ?

 

[WFarm]

I have never seen a GM backing plate with the adjusting hole. My Ram Chargers had them. I wonder if someone put a different backing plate on ? Some modern cars have little inspection plugs for lining wear on the back brakes so maybe you are on to something there.

Got pics ?

Yeah, the backing plate holes must be for checking lining wear. Backing plates have no holes that allow access to the adjuster. The backing plates have the metal plugs.

 

[Sgt Gus]

Ours had four holes, metal clips. One lined up with the star adjuster. I saw them on rock a uto yesterday.

 

[Old Guy Bill]

That hole gets a rubber plug on a whole slew of GM vehicles...
exactly which I don't know for sure.
I've seen a lot of empty's but never seen one melted.

 

[Grit dog]

Well, there is that to consider

Just wasn’t sure if drums would melt a rubber plug or not, as the service manual clearly says use metal plugs.

Millions (guessing) of drum brake rubber adjuster plugs bed in service. They don’t melt.

 

[Grit dog]

I have never seen a GM backing plate with the adjusting hole. My Ram Chargers had them. I wonder if someone put a different backing plate on ? Some modern cars have little inspection plugs for lining wear on the back brakes so maybe you are on to something there.

Got pics ?

I don’t think I’ve ever seen a drum brake backing plate without an adjuster hole. GM or otherwise. I’m sure they exist but commonly there’s a slotted hole on drum backer plates.

 

[Dejure]

I've been playing with and around rigs since the 60's. My experience is, the metal covers were the exception, rather than the rule.

Any time we knocked the factory cover out, and after finishing the brakes, we installed the rubber plugs, unless the hubs had the metal ones with the metal pressure clips that fit into the hole.

Generally, if braking could make enough heat to melt the rubber plugs, you've got MUCH bigger problems than a melted plug.

 

[Oldbear42]

I've run the rubber plugs for years without issues. In fact, the rubber plug was about the only part that remained intact during a 3-hour camping trip with a trailer bearing issue on the way home.

 

[Oldbear42]

I don’t think I’ve ever seen a drum brake backing plate without an adjuster hole. GM or otherwise. I’m sure they exist but commonly there’s a slotted hole on drum backer plates.

Our 2005 Yukon and our 2018 Santa Fe both do not have adjustment holes, but that is only for the parking brake (disc brakes with parking shoes) - Oh no, I had to buy "another" tool to do those jobs...