Brake experts, what's going on here?

I was checking my brake wear and I noticed a bunch of wavy grooves on this surface. The other rotor looks fine.
The pads still have lots of material. Hawk LTS pads, Stoptech rotors with 5th Gen 4Runner Powerstop calipers.

 

Just a guess but your calliper might be causing a bit of drag on your rotor. With your wheels off on both sides test to see how easy it is to spin the rotor.

 

have you done a bed in procedure?
Don’t know if I trust powerstop for a caliper.

The pads may be aggressive.
At the end of the day, if you still have
-pad material left
-rotor thickness left
-brakes work
-no pulsation

I don’t see an issue

hopefully the pistons retract when needed. And any moving parts clean and lubed. But again don’t know about power stop.
When I put calipers they are factory original and rebuilt myself. Which costs less than a cheap aftermarket brand that throws them in a tumbler and calls it a day.

 

That’s how my rotors look after high miles, like over 70K. How is the other side of that rotor? Does the pad also have wavy wear?

 

Mileage? How does the other side of the rotor look? Do you have a pulsating brake pedal when you apply the brakes?

FYI - I did the Powerstop Calipers and slotted rotors. Calipers froze after one winter up here (Nothern NH). Went back to stock calipers and rotors with no noticeable decline in performance.

Some good points made above about possible causes. Definitely check for piston retraction.

 

That's caused by the pads. Either poor quality or too aggressive. I see that on big landscaping trucks with semi-metallic pads

If the caliper was seized the rotor would be scorched from heat like blue and red and cooked looking. And the pad wear would be uneven side to side

 

Something along the lines of debris (such as mud) gets caught between the pad and rotor, and under braking, some parts of the rotor face get friction material and others don't.

I've seen this on a dual sport MC I previously owned.

 

Thanks all.

• First off, my brake setup is this:
  • Powerstop 14WA (5th Gen 4Runner Calipers)
  • Stoptech Slotted 4Runner Rotors
  • Hawk LTS pads
  • Larger Lexus dust covers
  • Stainless steel extending brake lines.
• I changed to this brake setup because the stock Tacoma brakes are terrible when running 35's on a 6000lb+ truck. So far performance has been great with no pulsing or vibrations in the pedal. I only noticed the grooves because I was checking the pad wear.
  • *Please don't reply with anything about how good the stock brakes are and how they work great for you. There are several of us that have heavy trucks and have found the stock brake setup is completely inadequate. (I'm not referring to your comments @TacoTuesday1, I just know how these threads can deteriorate)
• I performed a full bed in procedure after installing the pads and rotors.
• The pads are Hawk LTS which are very reputable, may be a bit aggressive, but I think less aggressive than EBC Yellow.
• I'll check again but I don't feel any dragging.
• I did notice that the grooved rotor had an anti-rattle clip and for some reason the other side clip was missing. Might just be a coincidence but something I noticed.

At this point I think I'll check for drag, replace the grooved rotor, pads on both sides, and clean/lube the calipers.

 

@nudavinci64, @crashnburn80, @lbhsbz What do you guys think? I know you are very familiar with this setup. Thanks

 

If you are hitting trails, this could be due to dirt/rocks that made their way in. I would also get that rattle clip added in. I had that happen on a Wilwood setup, and it wore the pads at a funky angle.

 

Brakes look fine to me, just well-seasoned. But definitely time to swap em out if you're having any issues.

 

You are correct the stock brakes suck.

I wonder if your pad is strong and doing it. I have TRD Ceramic pads which are supposed to be more gentle on the rotor.

not sure how to check for drag. Maybe spin the wheels in the air? Or coast the truck, let it stop from gravity up a hill without braking, then aim a laser thermometer at the rotors check for heat

if I had a factory caliper rebuilt myself with genuine kit I would just assume it’s fine

Theres also cooling ducts that can be added
But that may not be ideal off road
And temperature stickers that change color indicating a certain temp has been reached, more used on race cars to verify no overheating.

 

Pretty sure he is referring to the new brakes. Any on new ones I would put day dirt or rocks

 

@nudavinci64 yeah my question was on the first pic in the thread. The pic of the new vs OEm is from when I did the swap and was just for reference for the people that didn’t know what I am running.

here’s a pic of the pads and caliper on the grooved side:

 

If the grooves are consistent along the entire rotor then your pads will just wear to match them. And because that increases surface area, you could theoretically get better braking and cooling as a result.

 

Thanks all. I don't see any signs of excessive heat. I think I'm going to chalk it up to mud and debris for now. (the truck spends more time off road than on) Also, like I said, there are no performance losses or symptoms.
I'm seeing in another thread with @nudavinci64 that the current Stoptech product may not be as good as it was, so I'm going to look into other rotor options when I do my brakes. Possibly DBA but I need to figure out which ones fit.

 

It's the pads, it's not debris. It wouldn't be so uniform across the rotor surface if it was caused by a foreign object and if you were getting that much crap in your brakes to wear the rotors you'd hear it when applying the brakes. You mentioned your truck is heavy, I suspect you're seeing a result of that fact coupled with a pad that's somewhat aggressive. To me it looks like my rotors did with 70K on them. That occurred over years with not so aggressive pads, change the pad material to something more aggressive and it will happen sooner.

 

This is the answer. Everyone seems to have missed it haha

 

So it's definitely

• Heat
• Aggressive pads
• A stuck piston or dragging brakes
• Crappy Power Stop calipers
• Mud / Debris

 

I would go with the DBA4000 rotors. I had a set of those I was going to swap I before going to the full stoptech BBK kits. not any feedback on use but heard a ton of good things.