ajg617

Bumped into a co-worker at Audi Monday and he needs to replace his rear pads on his Q5. Does the Q5 require VAG to retract the calipers in order to change the pads similar to my 06 A6? I have the Ross Tech software and cable so I can help him out. I just haven't done it before on my own rear brakes. Not sure if the commands are the same for both vehicles.

Any advice on Q5 rear brake pad changes would be appreciated. He's ordered the parts and I would like to help him out. Just no familiarity with the Q series.

Thanks in advance,
AJG

MP4.2+6.0

Very similar to my D3, which should be like C6. They have just made the motor somewhat smaller and less noisy/faster acting than my D3. Audi rears have been just about the same basic set up for the past 15+ years, with the parking brake motor tweak. Basically, wind them back via VAG COM, take off the simple 13mm bolts that hold the caliper to the carrier bracket and you are there as you pull the caliper away and get right to the pads.

The Q5's have a balance/vibration weight on one of the two bolts, so remember which bolt position is which. OE pads from Audi tend to come with the stainless steel clips for the pad to caliper interface, while you re use them for many aftermarket pads. Can also be bought expensively as a piece part from Audi, or less so aftermarket from various suppliers if you know they tend to be sourced as separate parts w/ aftermarket pads.

At least on the D3 side, unplugging the parking brake electrical connector is a very bad idea and leads to a bunch of re-synching issues to get it back right. At the end, you need to set the new pad thickness in VAG-COM/VCDS of course. From experience, the laptop work can now take as long as the mechanical work. Still, an easy Audi job as they go, as long as you have the computer software and cable.

Bob Petruska

ajg617

Thank you for the input MP4.2+6.0. Just curious, is the pad thickness measured or do they spec it on the pads themselves (he's getting aftermarket - I'm guessing premium brake parts from an Audi shop)? For example, the rears on my A6 were done some time back but if I wanted to retract the parking brake motors for whatever reason, how would I set the pad thickness?

MP4.2+6.0

VAG COM/VCDS (or Audi's equivalent system) have two different relevant routines you can follow. One is just open close. The other is open and replace pads, then close. The latter assumes a pad change and then you enter a value for pad thickness in--in mm. You can enter any reasonable number, presumably with a maximum tied to the fault coding for the vehicle/brake set up. Thus, if you put in used or thin pads for some reason, you could enter a lesser number than for new pads. Based on that starting point number, system basically winds in the piston/brake over time and can then calculate the relative difference. When it gets to the lower bound thickness number, the light triggers. Thus, it's dependent on the first # you put in, as opposed to an absolute thickness or position calculation, at least as I recall off the top of my head.

Meanwhile, for the simple open close procedure, you don't touch the data about the pad thickness and it just picks up where it left off. Sometimes I have found a prior pad change data setting didn't take, so I have to enter it again and open and close pads to get system to reset and turn off light. As a caution for anyone doing this, I think you need to keep your laptop alive and NOT LET IT SLEEP THE WHOLE TIME you are doing the process, which typically means plugging it into the wall (or disabling sleep function entirely). If not, you can run into these finnicky issues getting the data to stick.

All this is from my D3 A8 experience; have not yet touched rear brakes on the Q5, but have reviewed the general set up carefully given my front RS5 brake conversion.

2011 Q5 3.2 White

I just performed a rear brake rotor and pad change out today, without VAC-COM. I removed the el connector from the calipers, provided my own power to reverse the Ebrake mechanism. I used a battery charger for the power source along with wire and a 5 amp circuit breaker just in case something went wrong. Before performing the job I removed fluid from the brake resevoir.
I did place a universal caliper tool into the caliper before backing off the motor just in case I had the polarity wrong. I did not want to pop the piston out of the caliper. Once the motor was backed off I used the caliper tool to actually collapse the piston assembly.
I performed the rotor/pad swap out. I reset everything by depressing the brake pedal several times with the ignition off. Then I turned on the ignition, held the PBrake button down while depressing the brake pedal. It ran for about 5 secs, and everything is fine. No codes, no lights.

Telate

When I changed them I just opened the ebrake, changed the pads, and closed it. i didn't have to set any values for pad thickness as it seems to do it according to the current of the motor. I've had no problems with the brakes in 1.5 years, so it couldn't have been wrong.

ELEVENS

Oh oh. How does the fact that it hasn't "broke" yet, equate to doing it right? How can current be a function of pad thickness? It isn't exactly going to blow up or anything, but without resetting pad thickness in VAGCOM, that little brake icon in the instrument cluster will be talking to you at some point before the pads need replacement.

hilld

The only change from the video is the basic settings. The latest VCDS software version does not have the numbers anymore 05 or 06 but instead in the dropdown it says something like put brakes into service position and end service position, other than that it is the same as in the video.

I just did this yesterday so it is still fresh on my mind.