Squeaking Just Like Before Despite New Pads/Rotors

Good day all,
I recently purchased a pre-owned 2015 Trail edition from a Toyota dealership. It had ~ 105K on it when i bought it about a month ago. I have only put on maybe 1500 miles. After about a week I noticed squeaking when breaking, and took it to the dealership as it has a 60 day warranty from my date of purchase. They cleaned up the pads and I went on my way. A day or so later the sound was back. Took it in again and they replaced all four sets of pads and rotors. Took it home, and it did it yet again, a little better, but not by much. Took it to the dealership again and they state they can't find anything wrong with it now. From the beginning (and still under set same circumstances) it only does it when slowing from ~ 30 miles or less. It also does it when I am on a trail, and by trail I mean light gravel with potholes. That is the most frustrating part because it is, after all, the trail model. When on the trail, (or anywhere really) it does it with very little brake pressure. It happens regardless of whether it is in 2H or 4H. Sometimes it's there, and sometimes it isn't. The ambient temp outside is about 85-90 in Connecticut right now. I am asking if anyone has any experience with this same issue, and what y'all think it may actually be as the dealership is providing no further answers. I plan on taking it in again, but I want to have some idea if I can before I go back. A video (poorly narrated) is attached to better explain.

 

I had uneven wear between the inner pads vs the outer pads, so I figure my calipers are starting to seize. I've ordered some parts but in the meantime I thought I'd rotate the pads so that the fresher pads are in place of the worn out ones while I wait. A bit of a silly idea but I'll see if it works and buys me some time. The OEM brakes have a separate shim plate behind the pads that is supposed to prevent squealing as well, mine were starting to disintegrate. I cleaned those up and I applied a thin layer of brake grease to both sides of these shim plates.

Upon doing this my brakes squealed horribly. So I went and bedded the pads into the rotors as if they were brand new. To do this find a road with no traffic, hit the gas to 40 MPH and then apply the brakes aggressively down to 10 MPH. Repeat this for a total of 5 times. Do it again from 35 MPH to 5 MPH another 5 times. You should do this in quick succession and aggressively to get the brakes nice and hot. DO NOT come to a complete stop when your brakes are hot though. After this heating procedure, drive for a while without using the brakes at all to let them cool off.

This fixed my problem. I haven't noticed any squealing since. Otherwise I'd check that your brake pins are lubricated allowing the pads to slide freely (seeing as the dealer took them apart and put them back together I would assume that is not the problem).

 

Thanks for the reply! They just replaced everything sans the calipers and I even made it a point to ask about the calipers as I know these have issues with seizing. I suppose it could have been oversight on the dealership’s part. Thank you for the detailed bedding process and I’ll have to try that again. I can sort of deal with the noise on the road, but when it comes to going off road that makes it hit the feels a lot more.

 

It is my understanding that if used heavily, hard, and enough to get the rotors/pads hot enough, that they glaze. Glazing of the rotors and pads will cause that squeaking sound. It is an issue with folks buying used Shelby Mustangs. The cars have been abused or "tracked" and have pushed the rotors and pads to the point of overheating. Glazing is the result. In that case, the rotors have to be replaced and not just the pads. I wonder if the calipers get warped from the excessive heat. That wouldn't be the case with a 4Runner, unless someone has been abusive to the brakes in an off-road setting.

 

They were replaced around two weeks ago and only used to get to and from work. Per the dealership and the car fax the car only had one owner before myself and it looks as if it was hardly ever taken off road. I think my anxiety is probably getting the beat of me, but I would rather iron out this cars issues before the warranty expires. The payment is already high enough without repairs/maintenance.

 

Maybe some inferior parts. It wouldn't surprise me the way the supply chains/manufacturing has been disrupted by Covid-19.

 

I know it’s a long shot because this post is almost 3 years old, but did the OP ever find a solution for this? My 2018 4Runner is doing something very similar. Starts a squeak,squeak,squeak sound after (when brakes aren’t applied) heavy breaking or downhill breaking and then goes away slowly after about 35-40. Very frustrating as pads/rotors have been replaced and it can’t be reproduced once it’s up on the lift. HELP please!!!

 

Check your wheel bearings.