high pitched squeak while breaking

What "oils"? You mean the brake disc oil that is applied only for transport? Cause it supposed to be removed before putting discs on.
Can you please explain, you did 27'000km and then went for service and they tolled you that pads are ok? If so then how long are you driving after servicing?

According to the manual:
- If you hear a squealing or scraping noise (brake pad wear limit indicators)
Have your Toyota dealer check and replace the brake pads as soon as possible.
The rotor damage can result if the pads are not replaced when needed.
It is dangerous to drive the vehicle when the wear limits of the brake pads
and/or that of the brake discs are exceeded.

 

there are anti squeal parts in the disc brakes, and luberication. have it all checked out. how many km on her?

 

Second the question: how many kilometers has the car been driven since new?

Get the brakes checked, front and rear. The rears have the wear indicator tang; it'll start to squeal when those pads are getting low. Could also be the brake caliper pins are seizing, need lubrication.

Have you ever had the brakes inspected, serviced?

 

Most likely, if they make a high-pitched squeal when you brake, it's the pads beginning to wear.

You have two choices:

1. Replace the pads right away; don't wait more than two weeks.
2. Wait until the pads wear down to metal and scrape up your rotors, tripling the cost of the repair

Of course it may be something else, but most likely, you have one or more worn brake pads. It's not difficult to do yourself.

 

If you work on the brakes yourself, be sure to disconnect the 12 volt battery first. You might be ok if you're careful to not open the driver's door (will activate brake pressurizing), but I'd say disconnect the 12 volt, even safer.

Also, if you push in pistons to gain clearance for new pads, last thing before reconnecting the 12 volt battery, press the brake pedal multiple times. You want to remove any excess travel, which could cause the computer to trigger warning lights, store a fault code.

Also, when reassembling the rear brakes, be careful to ensure the back of pad pin falls BETWEEN the spokes on the face of piston pattern. Then hook up 12 volt, then do the brake pedal pumps, then a short test drive, and only then apply the parking brake. This is to ensure that pin stays locked between the spokes. If the pin fails to stay locked thus, rides up on a spoke, your rear brakes will drag, pads wear uneven, rotors score, and on and on.

 

For retracting the rear brake pistons one of these is handy:



You can use something like needle nose pliers, but it's a pain. Harbour Freight refers to it as "disc brake piston tool".

 

I understand that the piston has spokes, but I don't understand what the "pad pin" is. When I look at the back of my brake pads, they seem perfectly flat.

 

They're just on the back pads, basically to prevent the caliper piston rotating when the parking brake is applied:



(These are the new ones I was just about to install, after a previous mess up. )

 

Got it! Thanks, Mendel, you're the bomb!

 

That's very low use, odd. Can you tell if the squeal is coming from front or rear? You might be able to do a quick check of the rear yourself. I'm not sure of your situation, if you have any tools, a garage or parking spot, but regardless you should be able to do this:

1. On level ground, preferably concrete paved, block the front-right tire. Proper wheel chocks are best (and good to have), but pieces of wood will do.
2. With parking brake off, using the supplied scissor jack at left-rear jacking point, raise that corner enough to get the wheel clear of the ground, and try spinning it. It should be relatively free spinning able to rotate a revolution at least. A little drag is ok, but a lot of resistance indicates a problem.

Then repeat chocking front-left and checking right-rear.