Rear drum brake plug important?

When I was under the truck I noticed that the passenger side rear drum brake is missing a rubber plug. How important is this and should I plug it? Also noticed the covers for the rocker panel holes are losing their seal. Or maybe they are supposed to be like that to allow it to vent and drain? Any recommendations on those as well?

 

Driving without a rubber plug in the brake shoe adjustment hole can lead to dirt entry. If you go through deep enough water, that water will also get in. The plug that you show in your photo is round. My plugs are oblong, and all the plugs I have ever seen are also oblong. And they are located at the top of the backing plate - yours appears to be somewhere on the side, so I'm not sure what that hole and plug are for.

In any event, I recommend that you buy and install a new plug. The sooner the better.

 

I think you might need to take a peek inside. That looks like a hole for the shoe anchor.
Not that the rear brakes on these trucks work anyway.

The cab seals are about the same effectiveness. I steer clear of deep water knowing the cab will fill pretty easily with water. I've seen daylight from the inside since the truck was fairly new.

 

That round plug out at the edge of the backing plate is for a quick look/see at the brake shoe lining thickness. Granted only one tiny spot of one shoe can be seen, but that is what it is for.
There should also be an oval plug just above the axle to access the brake adjuster "star wheel".
Rockers look normal.

 

Oh yea, I didn't snap that you inferred the other side had one. That is the spot that wear takes place the most.

 

I spray my truck off underneath often and have done some mild water crossings so I will plug that asap. I will inspect my drum brakes to make sure things look okay in there. Thanks for your reply

 

Good to know thanks. I am thinking of plugging the rocker holes with some rubber plugs that actually seal. Do you think that is a bad idea? Maybe drill a small hole in the plugs to allow moister to escape a little?

 

Yes and no. That plug just fills an inspection hole when you're not actually inspecting the shoes. Not having it there will allow some more water or dust than usual to enter the drum, but nothing you need to be concerned about in the short-term. If you're in a water crossing that's deep enough for water to get in through that hole, it's already entered through the gap between the drum and the backing plate anyway, so any extra that comes in through that hole is negligible.

It should be replaced at some point, but you don't have to stress about ruining your brakes if it takes a week or two.

 

I will get under there again and check for the oval plugs thanks.

 

I was unaware water can get in from the gap between the drum and backing plate, that is good to know thanks

 

Had the same problem… just got done replacing my rotor and groaned at the thought of finding a replacement. However, break bleeder caps work semi perfectly to seal the hole up.