Parking brake ineffective

[Eric Le Baron]

Replaced all brake discs and pads yesterday, all from ATE.
The discs were coated with greyish stuff.
First time I used the brakes they made a noise as if the pads were mounted with the metal part facing the disc!
After braking a few times the coating was gone (where the pad touches the disc).
As the same coating is on the inside of the rear discs I wonder what to do to remove it.
Right now the parking brake is not really effective anymore...
Should I use a similar procedure to wear off the coating on the inside of the rear brakes or should I have sanded the disc?

[jdstrickland]

Metal part facing the disc? That is 1.) stupid, and 2.) all but impossible without putting in some extra effort. How does one mount a pad backwards.

As for the Parking Brake, it's necessary to adjust them so that they work. The service brakes do not need to be adjusted, but the parking brakes do. I hesitate to detail the process to a guy that figured out how to install pads backwards.

[Eric Le Baron]

Never said the pads were mounted backwards (although this is possible).
Said: "they made a noise as if the pads were mounted with the metal part facing the disc".
Just to explain the sound I heard.
I did adjust the parking brake correctly.

[jdstrickland]

Originally Posted by Eric Le Baron

Never said the pads were mounted backwards (although this is possible).
Said: "they made a noise as if the pads were mounted with the metal part facing the disc".
Just to explain the sound I heard.
I did adjust the parking brake correctly.

Sorry, I missed "as if."

To adjust the parking brake, take the boot up at the base of the handle and loosen the cables -- two of them. Then take a lug bolt out on each side -- no reason to take the tires off, just raise it off of the ground. One side of the car has the adjusting starwheel at about 1:00, the other side has it at about 11:00. Using an appropriate tool, turn the star wheel until the brakes just begin to drag. Turn the star a few turns, then rotate the tire, if the brake drags then you are done, if not then repeat. When you get the brakes to drag SLIGHTLY, then go in and adjust the cables so that the handle sets the brakes at 4 or 5 clicks.

If you installed a hard brake pad, then the noise it makes will sound somewhat like metal on metal. Low noise (soft) pads make more dust. Hard pads make less dust, but more noise. A signature of hard pads, besides the lack of dust they produce, is that they tend to grind or squeak right at the moment that the car stops rolling. As you approach full stop -- the final 1 or 2 mph -- a hard pad can make noise that sounds like fingernails on a chalk board. Hard pads resist heat better, but they also work far better when hot than when cold. Most drivers have cold brakes, and soft pads work much better for these people than hard pads. If you drive mountain roads and use the brakes a lot, then hard pads will serve you well because you get them warm and keep them that way. But if you are a freeway flyer that does not use brakes a lot, then a softer pad is actually better for you. That is, the performance will be better, even if you don't enjoy the brake dust they make. Instead of a ceramic material, a semi-metallic might serve you better.

[Eric Le Baron]

Just back from doing what you said Scott.
I replaced the mph by km/h afraid that I might ruin the brake shoes when using the handbrake for too long or at a too high speed.
No e-brake button here, it's a E53 built in 2003 (218PS).
Handbrake is as effective now as it used to be
Pretty sure the coating is gone now.
Yes I did clean all the brake discs with brake cleaner before installing them just in case they would have an oil-based coating as well.
Cleaned them after installing them again.
Just read on THIS page (the manufacturer of my brakes and pads) that they "can be fitted directly without cleaning or additional treatment".
Although they also say that "the coating does not lead to any significant reduction in the friction coefficient" I feel a much better deceleration now compared to yesterday.

I am a high speed freeway flyer often doing 120mph (legal on most roads I'm driving).
Had to replace the discs due to excessive rust on it...
No idea what kind of pads I have.
According to the manufacturer: "ensures full braking performance from the very beginning".

Thanks all

[Joshdub]

You might have to wear off the coating with the parking brake in a similar manner as the rotor surface. If it still doesnt work then you are in for more adjustment. I highly doubt you are required to sand them.

[gatojurko]

If u have not done everything wrong... parking brake should be ok! It is automatic! If u r driving and would like to drift using parking brake it will be impossible! It is soft in that moment! Parking brake is only to hold the car on position! Stop some where on narrow and try! I do not know what u mean it is not really effective! I used to think like u ehen I wanted to turn car by 360' when driving

[Eric Le Baron]

For the mandatory yearly technical check of the vehicle the brakes and the parking brake need a certain minimum braking capability.
Right now the braking capability of the parking brake is not sufficient.
This must be caused by the coating in the brake disc.
With the old brake discs it was ok.
I did correctly adjust the parking brake again after the brake discs were changed.

[Scott ZHP]

Find a stretch of straight road, with no one behind you from about 40 mph, depress and hold the the e-brake button and gently pull the handbrake up until you slow to about 10mph. Repeat. Brake coating/Zcoat inside the drum is now gone.

You did remember to clean the ebrake shoes with brake cleaner, correct?

[Scott ZHP]

Glad it's sorted.

The e-brake button I meant is the low tech round one in the end of the handle.

And I did mean brake SHOES, not rotors/pads. There are a small pair of shoes that fit inside the rotor hat, it's good practice to clean these with brake cleaner. The adjustor tightens or loosens their position inside the hat and the shoes are what do the holding.