When to service drum brakes?

2017 SR5 2WD V6 135K on the odometer. I live in a hilly area and do typical suburban driving. Front pads have been changed twice, front rotors once. When do the shoes on the rear drums usually go out? I know you can check then and measure their thickness, but if I'm going to go through the trouble of taking the wheels and the drum off I figured I might as well just replace them at that point.

What would be a sign, other than checking the thickness of the shoes themselves, that the shoes need to be replaced?

 

If you have to pull the parking brake farther than you used to then most likely they are worn or need adjusting.

The only real way to know is take the time to pull a rear wheel and drum and inspect, it’s a 20 minute job or less.

 

With 135K on the clock, you might be getting close. And I'm not sure if the Taco's have one, but most old school drum brakes have a little inspection port on the backside of the drum. You popped the little rubber cover off the port and you can see the brake shoe thickness.

 

Its not a bad idea to at least pull the drums, clean, lube the contact points, measure the shoe thickness (Min is 1mm, new is about 5mm), and then adjust them properly too.

I have a manual and pulled mine apart at 96k and still had 2.5mm left. I have seen automatics needing them replaced at 90k, it all depends on driving style.

If doing them, replace the wheel cylinders and bleed all 4 corners while you are at it.

 

Agree with above, don't go to the trouble of replacing them just because you're taking the drums off to look. Toyota rear brakes notoriously last a long time. I'd just give them a clean and adjust and keep rolling

 

There is an inspection plug. That is how the I'm not sure how dealers measure since Toyota weirdly has a sticker between the drum and hub that is a PITA to remove the first time, and clean up.

 

The only thing I have ever been able to see through the hole after removing the rubber plug is the adjuster wheel.

 

I dont think there is. The rubber plug is for accessing the star adjuster, but you cant see the shoe thickness bc its in the middle of the drum.

Its a pain to see the star adjuster sometimes too, but I have older eyes too.

 

I will take a peek later.

I know they gave me measurements during the ToyotaCare services. I didn't check the drums until after that. Kinda need to get in there again to lube up the brake cable.

 

200k+ miles on three different 3rd gens and I never replaced the rear brakes. Front pads and rotors would go about 80k.

 

Best way to know is to just inspect them and inspect the drum (edit - by taking off the drum - the only way to fully inspect). You might get lucky and find a mud dauber nest or two nestled in there somewhere.

I just changed mine a few weeks ago at 112k. About 20k miles spent towing a 2500lb pop up camper and it's a moderately heavy truck.
My pads were noticeably thinner and ready to be changed but cold have easily squeezed out another 10k safely, if not a little more.

 

There's no shoe lining inspection plug so the drum has to come off. My wheel cylinders say "Advics" so I'd be reluctant to replace them with anything else. Checking the rear drums is a opportunity to make sure both left and right are wearing evenly and that the automatic adjusters are ratcheting correctly.

 

Some of the smaller cars like matrix and corolla and camry have the little inspection plugs up higher on the backing plate, separate from the adjuster plug

Pretty sure the trucks do not

 

My apologies! Might have confused the adjuster. Will edit the post.

 

There were always two covered ports, one for accessing the adjuster wheel and one to view the liner thickness. I'm just too sick to crawl under there to verify that the Tacoma has both.

I can't imagine that it doesn't have both, but then again what the hell do I know!

 

I have a 17 TRD Sport and there is an inspection plug to check the shoe thickness as well as the adjuster. But, remember you are only checking the thickness on a small area. It is best to remove the drum for a full inspection.

 

Is the "wheel cylinder" the drum housing itself?

 

The wheel cylinder attaches to the housing and pushes the shoes toward the drum when braking.

 

Its the little cylinder with the brake line going into the back of it

 

Okay, the saga is over. When I got home I took some pictures of my 2023 Tacoma rear brake backing plate. There is only one rubber plug that reveals an access hole directly behind the brake adjuster.

There is not a second hole to inspect brake liner wear so you have to remove the drum.

Note: Image number three is an internet photo to show the rubber plug with access hole is directly behind the adjuster.