Auris rear brakes squeaq

[mtl]

Car: Auris Hybrid, 2011
When car is not used for a day or two, rear brakes start squeqing as heard in this video.

The sound appeared cca. 1.000km ago or I did not notice it before although I am usually pretty good at that. After cca. 5 kilometers the sound disappears or is not noticable anymore. Brake pads (TRW) are basically unused, brake discs (I do not know the manufacturer) are slightly used, they have a really small edge around. The sound is heard from both rear sides. Front brakes are perfect. I had the brakes cleaned and greased at a garage, but the sound is still present.
The garage said that probably the brake pads became hard and this is causing the sound. And that is finished for them. If needed I will go with brake discs/pads replacement, but before I start throwing money at the problem: what could be other possible causes of this sound. Since both sides are making this noise I would think that there should be a one cause of this - maybe handbrake not disengaging correctly. Handbrake is always used when parked.

Due to really bad garage experience I will tackle this myself, even though I did a lot of work on the cars myself, I was not comfortable to deal with brakes. But the time has come to work also on the brakes.

Thank you for all your suggestions.

[tavy]

Hi Igor,

I have TRW brake pads fitted on other car and they are squeaking too, but the brakes are very good and I don't bother too much as long as the brakes work perfectly. Even Bosch brake pads of my Auris are squeaking sometimes.

Almost all modern brake pads are squeaking because they don't contain asbestos and make small balls of glass when working at high temperature. When you hear them squeaking, press the brake pedal hardly, in this way you break the micro glass balls and sound disappears.

[mtl]

Hi, thx for your input.
But I have not yet had a squeqy brakes on my car. I always use ATE parts, these brakes came with the car from previous owner. Also there was no sound from purchase (last year) and for last 40.000km, so I would like to solve this. The sound is even more problematic, because it is a hybrid, so many times there is no engine sound, just this sound.

[tavy]

  Yes, you brakes sound is more friction sound rather then squeaking brake pads; it looks like you have sticky caliper pistons, so  your calipers need a good cleaning.

  Try to clean the calipers and put some WD40 under the piston grommet then retract the piston back.

[mtl]

You are right, it is a friction noise. Calipers should have been already cleaned (at least that was paid), but I will check myself again. Also piston movement is perfect according to garage info. Though, they also did not hear this sound when testing.

[tavy]

  Yeap, you would better check again the calipers by yourself, what is done with your hands is better than others do. For example, when I work at my car brakes sometimes I spend 3...4 hours, but the people from a garage finishes in 30...40 minutes. This job includes applying WD40 under the piston before retracting, grinding the disk lip and measuring the disk thickness.

[Stivino]

52 minutes ago, tavy said:

  Yeap, you would better check again the calipers by yourself, what is done with your hands is better than others do. For example, when I work at my car brakes sometimes I spend 3...4 hours, but the people from a garage finishes in 30...40 minutes. This job includes applying WD40 under the piston before retracting, grinding the disk lip and measuring the disk thickness.

I can pretty much guarantee you that no fully trained motor vehicle technician will spray WD-40 behind caliper rubbers. Nor would they grind a brake disc.

[tavy]

  Of course, is simplier doing nothing than changing brake pads and disks or in most complicated case, entire calipers. 😊

  I'm doing this for three decades and no problem with brakes till now.

[mtl]

It is not about doing nothing. It is about doing it right and I know that you should be really carefull what grease/spray you use on the brakes, especially on piston rubber because it can damage it and you have a bigger problem than friction noise ;).

[tavy]

This is my humble opinion, everybody does what he wants with his car...

[Toyota Nige]

Mine squeaked and Toyota required paying to clean the calipers. What annoyed me is they had done a major service three months earlier and they claimed where clean. Bearing in mind I had done 80k and still had 8mm pads (I drive it like a hybrid - hardly any braking), in three months I was down to 3mm and required changing. I have now done 120k and still have 3mm!

[mtl]

It is the same with our car. Brakes are hardly ever used.
Except I try to do a full braking on  the highway (no cars behind) every 14 days, just to ''clean'' them.
Were they squeqing or there was a friction noise?

[TonyHSD]

Hi, 

The noise is excessive and mechanical. 
You need to take all components apart and clean everything properly.
Check your slider pins for having corrosion and been pitted, if yes replace with new or clean to shiny metal your existing ones until new one arrives. These are very tricky on Toyota cars and particularly hybrids.
The best way to grease them with silicone grease is to put some grease inside the holes with a small screwdriver, then apply some grease directly onto them and insert in while turning them , move in and out and squeeze the rubber boots to get any locked air out and fill the boots with excess grease to prevent any moisture and water coming in later , when fully fitted they should not poke out but move freely in and out and stay whenever you leave them. Don’t go crazy with the grease but make sure there is some inside and sliders are free to move. 
For the pistons you will need a tool to rotate them back in and very important to stop at correct place with grooves cut top and bottom, this is to allow proper fitting of the calliper and brake pads.
Re pistons, you will need someone to pull handbrake and release so you can watch the pads been compressed and released, free movement of the piston. If you spray anything on it should be wd-40 silicone spray only., brake cleaner spray it’s fine too. 

Remember before working on Toyota hybrids brakes you will need to depressurised the brake system and disconnect the 12v Battery negative terminal, put a towel on top of the boot lock to prevent accidentally closing the boot door, you can’t open afterwards.
After replacing anything and all is put back in, use your handbrake and pull up and down few time until the brake pistons apply pressure to the pads, release handbrake down. Then connect the 12v Battery and start the car normally, press brake pedal few times, engage and disengage the handbrake, turn off the car and wait for brake system to depressurised.
With wheels on the car and torque to specs and car off the ground turn them and see if they rotate freely each side, if there is a lot of resistance you may need to recheck your work. Little noise from touching and little resistance it’s fine, you can feel if it’s not ok. Test drive the car normally and stop and measure temperature of the discs, anything above 44C° means the brakes are stuck and cause dragging.

Good luck 

[mtl]

Thank you very much for this detailed info. I have already read that you need to disconnect the Battery on hybrids, because brake system is pressurised immediatelly with opening the driver doors (if I remmembered correctly). You can also hear it, when opening the doors.

[TonyHSD]

2 hours ago, mtl said:

Thank you very much for this detailed info. I have already read that you need to disconnect the battery on hybrids, because brake system is pressurised immediatelly with opening the driver doors (if I remmembered correctly). You can also hear it, when opening the doors.

No worries. 
Before you do any work check wheel bearings for free play and noises, they can do sometimes exactly like brake pads.
Then check your back plates discs protectors, those get easily bent and touching the discs and finally check your pads for uneven wear, this can happen if the pistons aren’t set at correct turn with groves open top and bottom or stuck slider pins . When this happens the pads will wear on one side and although they look good they might have gone and the wear acoustic plate touches the discs it will produce these unpleasant noises. To check that slightly press brake while car is slowly moving and if the noise disappears it’s very likely from them, but you gonna check when take all apart anyway. Don’t change parts unless worn out. 👍