Rear Brake Pads - head hurts

The assembly plant doesn't bed in the brakes. They take the truck up to about 80 mph on a treadmill and make sure it tracks straight, that's about it.

Some pads advertise "no break-in required" or "thermal scorched to minimize running-in and fading".

 

As I understand it, rotors don't warp in passenger-vehicle usage. They have to get extremely hot (glowing?) for that to occur. I too was guilty of thinking I had warped rotors on my 2001 4Runner. But I can guarantee you I never got them hot enough for that lol.

 

Amen. The other race tech that's counterproductive on the street is steel braided lines. I remember these being popular when I was into Japanese tuner cars in my young, dumb, phase. The theory is that the braided lines give you a stiffer pedal feel, and while that may be great on a track people didn't realize the street driving problem is dirt and debris getting on the lines works its way though the braid and can damage the inner line. Its not an issue on dedicated track car as they get inspected all the time.

 

This is also a good watch before you choose from aftermarket pads. Back in the day I mentioned above I used to use a lot of Brembo and Centric aftermarket rotors and Hawk performance pads but Ive gone back to using all OE on the SUVs we drive now.

 

So if you have pulsating when braking and have new pads, what’s causing the pulsing?

 

Were the rotors changed or just pads?

 

Just pads. If rotors can’t become warped, why change them? My understanding is rotors can absolutely become warped and that pulsating is due to minor imperfections/warping on the rotors.

 

Well, I usually don't replace rotors. When I do, it's either due to thickness, or simply because they've been in service for 200k miles or something like that. Not because of pulsating brakes.

While rotors can warp under extreme conditions, the few articles and studies I've read point to uneven pad buildup on the rotor surface as the primary culprit, as others on here have said. I used to think they warped fairly regularly, but looking at a rotor, it makes sense that they would tend to resist warpage.

 

Deposits on the rotor are often misattributed to warped rotors

 

Uneven pad material deposits from overheating, stuck caliper, etc. Problem is without having them turned to remove old uneven pad material the pulsation and vibration won't go away. Can't just spray some brake cleaner and wipe it off.

 

That is why I replaced both rotors and pads.. My rotors had lots of time left on them... I did not want to redo the job...
As others mentioned, the old rotor will not be smooth. So either change it or resurface.

 

Wrong, warpage is caused by the heat generated from braking. Ever used a micrometer on a warped rotor? I can assure you there is no massive build up of brake pad material under most situations. The rotors on my wife's Grand Cherokee are warped and absolutely no measurable about of brake pad material are on the rotor surface.

 

Actually both are true.. There is something called run-out gauge and will measure how un-even a rotor is... The point is used rotors will have uneven surfaces.....

 

Totally, but to call warping a myth is laughable.

 

Wrong. If you are getting uneven wear or grooves in the rotor, that is caused by seized/cocked pads and/or caliper pistons. Chrysler products are prone to it. Been there, done that.

Educate yourself on the physics of the problem:
https://www.motortrend.com/how-to/1808-nuts-and-bolts-warped-rotor-myth/
https://trade.mechanic.com.au/news/solved-the-mystery-of-warped-brake-rotors

 

I want a rear drum conversion.

 

^Unfortunately as I'm finding with the Tacoma, drums need yearly disassembly and cleaning if you go off-road. With discs you can aim a pressure washer wand at the caliper and flush out most of the dirt and silt after each wheeling trip.

 

I don't think "beefing them up" is necessary. Toyota OVERBUILDS their vehicles and OEM quality is fine. I went with brakes from DETROIT AXLE off Amazon and they seem fine.

 

The buildup doesn't need to be massive to cause this symptom. I believe it happens with <1/1000 inch of pad material.

 

My 2015 Tacoma TRD Sport AC brake rotors drove me crazy. I am an aggressive driver. At around 45k miles my brake pedal was pulsing (my fault, because of driving style) so it was time to replace pads up front. They wanted to turn the rotors, I said no, replace. At around 90k or so miles, it was time for pads again. My brake pedal was pulsing, of course. That's when I started doing some research.

Turns out, the 4Runner rotors and calipers will bolt right up to a TRD Sport Tacoma. So, I did so. Problem solved. Even with my aggressive driving, which has probably gotten worse because I am an impatient old man that refuses to put up with bullshit on the freeways, I am now very - no, extremely happy with my brakes on the Tacoma.

 

With NORMAL driving OEM quality should be fine.

 

Why do my brakes pulsate?
Well I thought of Wrenching with Kenny, but then found this: https://www.youtube.com/results?search_query=my+brake+pulsate

So, I recommend then some and wash them down with cause just way too many variables to address such a open ended question.

 

Obviously, I am anything but normal!