Sunday, February 20, 2011

When Engineers Get Bored...

2009 VW Tiguan rear caliper (removed), illustrating servo motor

...they design things like electronic parking brakes, where through the miracle of technology, they replace perhaps $250 worth of handles/pedals and cables with well over $1000 worth of electrical switches, control units, wiring, and servo motors. That is, of course, if they don't also use cables, as in models like the 2010 Subaru Outback.

2009 VW Tiguan parking brake control switch (located in centre console)

Theoretically, an electric parking brake does allow certain things, such as automatic application when the vehicle is placed in park - none that I'm aware of will do that, even if many will release when the throttle is pressed. Auto Hold, as seen here, will hold the vehicle when you come to a stop (until you press the throttle) so you don't have to stay on the brake in traffic, as well as preventing roll-back on inclines. Didn't a manual handbrake also do those things?

Using a switch instead of a handle or lever also potentially frees up space in the centre console which... ...wait a second, the Tiguan's switch is where the hand lever would go. No space gained there.

Well, you do get some added coin storage, I guess, but look at how much coffee has already found its way into the switch due to the proximity to the cupholders. This would, at worst, make a handbrake handle sticky, but it could potentially spell intermittent operation or even death for these two switches, which are not likely cheap to replace.

Speaking of not cheap, when the time comes to replace the rear pads (with or without the rotors), you now need to command the parking brake servo motors open, which requires either a VW-capable bi-directional scan tool, or a specialized, purpose-specific control device, like the one seen below. There is no other way to do the job properly, and you can bet the shop's added costs in equipment will be factored into the job.

Strategic Tools' 30369600 VW/Audi EPB service tool

We won't even get into Volkswagen's corporate fascination with unusual fastener drive systems, such as the "triple square drive" bolts that retain the brake caliper bracket (and, it appears, the wheel bearing assembly too). Thanks for making me spend even more on yet another set of special sockets - they'll complement the metric Allen drive set that already gathers dust in my toolbox between German car repair jobs...

2009 VW Tiguan - rear upright as seen from inboard side


  1. There's a VAGCOM tool scanner just for the parking brake? Jeezus. The Germans have too much time on their hands.