How to check brake pad thickness? No straw test?

Hi, I'm surprised nothing is coming up when I google this. In the past I've done the "straw test" on my other vehicles to see how thick my brake pads are to estimate when they need to be replaced. Instead of a straw I use Vernier Caliper's (the measuring tool) which is more accurate. But it's really quick and I don't need to take the wheel off.

I'm suspicious of the brakes on my Tacoma so I grabbed my tool and was surprised to notice the calipers on the Tacoma's seem to completely cover the brake pads so I don't know how to get a measurement!

I'm no auto expert, and this is the first time I've even paid attention to the brake calipers. Is there another way to measure the pad thickness? Or is there a spot I'm not seeing where I can take the measurement (do I need the wheel off for this)?

Also, is there anyway to get a measurement for the rear drum brakes? I was under the impression you have to take them completely off. But i'd rather not do that if they don't need to be changed!

Thanks!

 

I just check the front pads when I rotate my tires. I don’t bother checking the rear since they will last over 100,000 miles for most drivers and there is no easy way to do it without removal. Make sure to use your E-brake from time to time to keep everything calibrated. Also use the search tool for questions like this, this place is flooded with great knowledge and posts that cover this in great detail.

 

Hi, and thank you kindly for your response! I was surprised when I originally searched here that I couldn't find this question asked before. Unless there's some tip on how to better search, all the posts that come up are regarding specific brake questions not relating to "how someone can perform the brake pad check". That's why I like to keep the titles of posts to forums as specific to the question I'm asking. It makes it much easier to find when searching.

I did scan through a number of posts but it's a shot in the dark if someone happens to mention how to perform a break pad inspection. Have you really seen this question asked here before? Because I understand how annoying that can be and was surprised I couldn't find anything.

Do rear drum brakes really last 100k miles?! I didn't know that! Do they make a sound when they're low? I'm not sure how to keep an eye on them! (I'm trying to do my due diligence as a vehicle owner.)

You mentioned checking your breaks when you rotate your tires. I went ahead and jacked my Tacoma up and took off the wheel to see if I could find a better spot. I think I found a place to measure the outside pad, but it was very hard to find a spot to measure the inside pad. When you check your pads are you just looking visually or using an instrument. I'm using a Venier Caliper because I thought this was best, but I never tried it on a Tacoma. Now I'm realizing because of the tight squeeze I may have been luck using one of these specific "brake pad measuring tools",

$32 OTC 6596 Brake Pad Gauge

here or

$13 Steelman 8-Piece Brake Lining Thickness Gauge Set for Mechanics, Use with Disc and Drum Brake Pads, Color-Coded, Steel, Stamped Metric and SAE Callouts

here.

Anyhow, having only taken off and measured one wheel, I got 12mm which surprised me. In fact I could see the piece of metal (which lives on the inside pad) that scraps when it's too low, but there was a few millimeters space there, so I know what I'm hearing isn't on that side. Maybe it's sand...

I'm explaining all this in case you feel I'm doing something wrong or should try another method. You're input is greatly appreciated.

 

My rear brakes on my first gen had 350k on the originals, I would do a clean and adjust on them every 30k. It really is amazing how long they’ll last when properly maintained plus the rears do not do a whole lot of the braking on these trucks.

 

You should just be able to take your tire off and look at the back of your caliper? You can easily see the pads and how much is left on them

Ignore the red arrows that has nothing to do with the brake pads lol

 

You can see the front pads with a little pocket mirror and a flashlight

 

First front pads on mine at 85k. Put rears on mine at 125k as had bought them and they really did not need them but once all apart did them as I get salt water in them sometimes on boat ramps. The drums were groovy so replaced them too. I gave up turning drums along time ago. If your parking brake gets used a lot (use mine on ramps as I solo launch) the adjustment for that is inside the center console not under the truck as lots of American ones are.

 

That's to all you for your feedback. I've learned a few things, most surprising that the rears last as long as you're saying! As a father with young kids I like to make sure everything is working correctly. That's why I like to take an actual measurement of the front disks. But I'm still unsure how to check to see when the rears need to be replaced. At least I know at 80k miles I may have some time still.

 

You have to remove the rear wheel and then remove the brake drum by screwing bolts into the plugs or using a prybar. This video covers it if you watch the first 2 minutes.

 

If you check the rear pads.
It’s a good idea to back off the adjustment screw before pulling the drum.
Especially if the shoes have a lot of miles on them.
If the Pads have worn the drum enough to form a lip or groove on the inside edge of the drum.
The edges of shoes, can catch on the lip/groove, and damage the shoes on removal.
Once checked, don’t forget to readjust the shoes.

It is essentially the same groove you see on rotors.

 

YES!!!

This happened to me at about 200k. I did this and it ripped the pad out and busted the brake cylinder. Complete disaster. I replaced mine at 200k and they were pretty worn, but still could have gone another 50k

 

Isn’t it funny how we tend NOT to forget the things we learned the hard way?
My experience wasn’t near as bad as yours. Mine just barely scraped the the edges.
I got lucky, that time.

I’m sure all the diff fluid covering everything helped things slide.
You’ll get to know your brakes if you ever replace the axle seal.
Not the most fun job I have done. But not the worst.

 

For the fronts I just use the groove in the pad as a measuring reference. When it is nearly gone it is time to replace them.




Also on the rears there is an inspection port;



The Red Line is pointing at the ROUND inspection plug. Harder to actually measure them, but this is where the dealer looks when the do their inspection. They don't pull the drums.

The OVAL plug is for the adjustment star wheel.

 

Wow! Thanks everyone! Now I feel all my concerns and questions have been answered and hopefully someone else who discovers this post will find this helpful as well!

I really appreciate you taking the time to post pictures and all explain all these details!