Brakes: Reference New Parking Brake Performance

[SwissXC90]

Having suffered a rusty (though lack of use) poor parking brake failing the tough vehicle inspection here in Switzerland, resulting in a repair to as-new condition by the Volvo dealer using new original Volvo parts, I though I'd write a parking brake reference description for everyone.

The Volvo dealer did the right thing by getting the rear braking system to as-new condition to guarantee performance. Yes, it cost money. But now it works. Properly. Perfectly.

Parts
Volvo MY2009 XC90, parts fitted:

1. New rear brake discs (disc and drum are one piece)
2. New rear brake pads (foot brake)
3. New rear brake shoes (parking brake)
4. New rear brake springs (parking brake)

Parking brake performance (foot pedal clicks)
0 clicks: car rolls freely, no drag
1 click: noticeable drag on a flat surface, at idle the D5 is only slowly moving the car forwards or backwards depending on selected gear.
2 clicks: easily holds the D5 motor at idle on a flat surface, in D or in R. Holds the car on a slight gradient.
3 clicks: solidly holding the vehicle on a flat surface to a medium gradient
5 clicks: solidly holding the vehicle on a 17% (steep) gradient, pointing uphill, with motor in D (motor is providing some brake assistance). Take motor out of D and the vehicle starts to roll backwards down the slope ever so slowly.
6 clicks: holding the vehicle solidly on a 17% (steep) gradient, pointing uphill or downhill, with motor running and gearbox in D, R or N.

The parking brake mechanism has 8 clicks in total, so from the 6-click point you have a reserve of 2 clicks to allow for wear in the pads, before it needs readjusting.

Regulations
Swiss regulations state that the parking brake must hold the fully laden vehicle on a 18% gradient. That is exactly what the testing station tests. We call it the mountainside test (Berghang Test), and we have a lot of mountains here.
An 18% gradient is a 1-in-5.5 gradient, which is quite steep.
I have a 17% hill (yes, it has a warning sign saying so!) close to home, and use that as my reference point. It really is steep. So steep they don't plow it in Winter. (Great place to test the AWD when snow is on the ground...)
If you don't know how steep the roads are in your area, simply choose the steepest.

To simulate the a loaded vehicle, test the vehicle on the 18% gradient with the motor running and the auto gearbox in the same gear as you are facing, to provide extra force to try and move the car.
E.g.: if car is pointing downhill, put auto gearbox in D to try and go forwards, down the hill.
If pointing uphill, put auto gearbox in R to try and go backwards, down the hill, both times with engine idling.

The parking brake should hold it solidly at 6 clicks.


I hope this reference info helps!
Maybe the Mods can make it a sticky....