Brake Pad & Rotor Bed-In question

I changed my factory brake pads out at 55,106 miles. I got some Duralast Gold pads from Autozone, new pins and spring clip. I measured the rotor with a caliper using a quarter and did the necessary math to determine they were 21mm in thickness, therefore good.

I drove around and followed the generally accepted practice of bedding-in the new pads.

It's been 3,000 miles since swapping the pads out. Rotors are good and I never have any vibration when braking.

During some prolonged downhill mountain driving with the truck loaded, I noticed that I got some minor pad slippage while stopping at a stop sign in a mountain town. The behavior was exactly the same during the initial 100-mile bed-in.

My question is why would this happen?

 

tell me what you mean by "pad slippage", did you mean the brakes did not hold? Could you pads simply have gotten overheated you experienced fade? I live ON a mountain and the Wagner Severe Duty Pads have done just fine for me. BTW, does Autozone sell ANY US made products?

 

The brakes were hot, no question about that. I think it may not have been the pads themselves but instead be the ABS motor... It was a pulsing sensation. The thing is I never experienced it with the factory pads, so I was assuming it was the pads. Several folks run the same pads without any issues.

 

or it could be moisture in the brake fluid...perhaps some bleeding would help.

 

Thanks. I recently performed a complete brake fluid flush with new quality DOT4 fluid.

Tomorrow I'll take a close look at the pads to see that they're seated correctly.

 

Are you downshifting to maximize engine braking? It's pretty much a must on long steep descents especially when loaded - no matter what your vehicle or braking system. All brakes will overheat and fade if used incorrectly, and since you changed OEM pads at 55,000 miles, it makes me think your driving style is hard on brakes, unless stop and go traffic is your normal. (I have very nearly double that on my OEM pads, drive very steep roads regularly, and tow occasionally, and yes, they are due for replacement any time now.). It isn't too hard to keep the tacoma's brakes cool on even the steepest roads if you keep your foot off the brake and let the engine do the work.

Another possibility is that you have a dragging brake caliper or two - making the brakes run hot before the hill situation comes into the picture. Feel for heat after a longer highway drive on flat terrain and a slow, coasting stop. Just don't touch the rotor directly.

When you say the brakes were hot, no question, were they hot to the point of stinking?

 

Thanks. Yes I downshift on steep descents. I had 4mm left on the factory pads, just got tired of hearing the noise from the free floating pads when going from reverse to drive and vise versa.

My truck has the hydraulic brake booster that was put in the off road model 4x4 trucks. I'm wondering if the pulsing sensation was the result of EBA, or some other 'feature' from the ABS system.

 

Yesterday I drove it hard and was braking hard and experienced it. I'm thinking for sure it was the EBA feature. My truck is heavy so it must be the weight of the truck, and the skid control ECU engaging the feature.

Today I had the front wheels off, so I cleaned up the pad pins and added another spring to the caliper. Pads looked good and wearing evenly.

At this point, I'm not concerned. Thanks.

 

Can you explain this measuring technique for the rotors some more please?

 

The proper way is to use a micrometer.

I didn't have one of those, but I had a slide caliper. What I did was I measure the thickness of two quarters. Then I put those quarters on the rotor face one on each side and then I measure the thickness of the rotor plus two quarters. Then subtract out whatever the thickness was of the quarters and that will yield the correct thickness of the rotor.

I believe the correct thickness for a brand new Toyota rotor is 21 millimeters. And mine was extremely close to that.

Here found this:

https://youtu.be/3xxRg_E1kgg

 

How necessary is it to do the bedding process for new brakes? I have always done it when installing new pads and rotors. I just can’t imagine that the dealership or small shops actually perform this procedure after installing new brakes. Usually on the bedding instructions, it gives you alternative instructions if you can’t perform the typical bedding process. They usually say to avoid hard braking for 250 miles or so.
Just wondering what everyone’s thoughts are on this?

Thanks!

 

I always bed mine when I change them but when you buy a new car with no miles on it, you can bet they're not bedded. I drove my daughter's new 2020 Tacoma home from Texas and the brakes seemed to work fine.
It's probably overkill but I re-bed mine in my truck just about every year. They always seem to perform better afterward. It may be a placebo, but it makes me feel better.