runbuh

I bought low-dust ceramics and had them installed by the my local dealer. When they tested the car, the SA that there was a loud "chunk" if you put the car in reverse, backed up, hit the brakes, shifted into Drive, went forward, and then hit the brakes again. I had them put my OEM pads back on.

Now the vendor is telling me that the dealer probably forgot to install the pad springs (the cross-shaped metallic clips). I trust the vendor (small shop that I've worked with since 1999!), but I also trust the dealer.

Any advice about what the real problem was?

I'm about to dive in and reinstall them myself -- I've done brakes before, just not on a Cayenne. This thread will help.

chiapet15

I got the Centric Posi-Quiet ceramic pads and had the exact same issue. It's due to more play in the pad that causes the pads to move up (when pressing brakes for first time after switching to reverse) and down (when pressing brakes for first time after switching to drive). The pads are supposed to be able to move because it needs to accommodate wheel flex during turns, where the rotor will not stay completely vertical between the pads. However, when the tolerance of the pad dimensions are a little larger, you get more movement.

This is quite normal and can be dampened with brake grease on the pins holding the pads. Also, the OEM pad springs are stiffer than the ones included with the brake pads, so I re-used the OEM pad springs since I changed out my pads with only 9.5Kmi on the odometer. I really like the smooth braking (less grabby than OEM pads) and virtually no dust. Although the initial bite is less grabby, I didn't notice any loss in stopping power, and the brakes are much easier to modulate when coming to a stop (no lurching as the car comes to a complete stop)

I copied below the thread from my conversation with a rep at Centric:
Centric wrote:
We’re dealing with a stamped backing plate, which isn’t going to be the most precise thing in the world. Brembo has designed this assembly to locate only on the pins…while normally they have the pad locating using the ends of the pads against stainless abutment clips which have a bit of spring action to them to account for minor dimensional differences in the backing plate lengths. The ONLY issue you will have is a bit of noise when changing direction. The lube will help damp this noise.

If the spring is weaker, I need to look into that on our end. You might try installing the OEM spring if you still have it, that may help as well. I would suggest any common silicone dielectric grease (tune up grease…the same stuff that used to come with a new set of spark plug wires). It’s high temp and thick, which is exactly what we want. This is very commonly used on caliper slide pins and other brake components.

Chiapet15 wrote:

Hi Centric,

I really appreciate the response. So if I understand this correctly, it's okay for the pads to move vertically in the caliper when some force is applied, so as long as the caliper springs provide enough tension to keep them from clattering against the rotor and caliper when going over bumps in the road? While the pads are not completely loose in the caliper, I can push them up or down with my fingers, which is something I couldn't do when the stock pads were in. The caliper springs that came with the pads appear to be softer (less stiff) compared to the stock caliper springs. However, I still can push the pads up/down with my finger when the stock caliper springs are used, but it requires slightly more force.

The brake lube will allow this necessary movement to occur, but with much less sound? Is there a particular brand of brake grease you'd recommend or is simply having brake grease on the pins the biggest factor in quieting the click?

Thanks,
Chiapet



Centric wrote:
Hi Chiapet, What you're describing is normal in many cases...you may try applying some high temp synthetic brake lube (paste) on the pins to dampen the noise.

-----Original Message (from Chiapet)-----

I recently installed the Posi Quiet ceramic pads for my Porsche Cayenne S ehybrid, and upon testing them, I found that a single click noise can be heard the first time the brakes are used after transitioning from forward to reverse or reverse to forward. I then checked the pads and found that I could push them up against the caliper springs and have the bottom edge of the mounting holes hit the mounting posts in the caliper. Given that the pads move this easily, and it is the same sound as when I'm backing in/out of a level driveway while applying the brakes, I believe there is excessive play in the pads. I understand that there should always be some play, but is there a way around this or is it simply a tolerance issue with the pad mounting holes being too large?

Note that the car has 9Kmi on the odometer and was purchased new last year. I also changed out the caliper springs to the ones that were included with the brake pads.

Thanks,
Chiapet

Make:
Porsche

Model:
Cayenne S ehybrid

Year:
2016

Trim Line (xl, xlt, ex, etc...):


Special Details (with ABS, Cruise, t/c, etc...):


Part Number (if question pertains to particular part):
105.13490

runbuh

Thank you for the quick reply. This is the wife's car, and she's not going to tolerate change very well. It was hard enough to get her to agree to something slightly less grabby (she prefers grabby). I think I'll stick with the OEM pads in order to maintain marital stability.

125shifter

I've had a clunk before after changing pads on other cars where the pad did not fit tight in the caliper and was able to slide back and forth in the caliper hitting the caliper inside edges when the pad came to a stop.

Joel 67

Hey guys,

Great thread. I have a 2012 CTT and will be doing a front brake pad swap at some point in the near future. In anticipation of the job and the desire to have as little downtime as possible, I want to ensure I have all necessary tools in hand prior to beginning any work.

I have most standard tools (including a 100+ ft/lb tq wrench). Some things I noticed in the article as being needed are:

T30 torx bit
T40 torx bit
M14 triple square
Lisle 25750 caliper compressor
assembly pin VW tool T10439

Are these everything? Thanks in advance.

Tom M

You don't mention it but be sure to have a decent size breaker bar on hand to loosen the caliper bolts. I needed to use a long handled one to get enough on mine to free them up.

TheUnscented

The front caliper bolts at T60 stretch bolts. You're going to have to torque them to 104 ft/lbs so get the 1/2" driven T60. The stretch bolts are $8.00 each from Pelican: WHT-004-572-OEM.
The rear caliper bolts are M14 triple square. About $3 each from Sunset Porsche: WHT-004-571

TheUnscented

The CTT front rotors are a T60 bolt, not T50. I had T50 & T55 in my tool box but had to run out to get the T60. You're going to need a breaker bar to get those bolts loose so you'd better get the 1/2" T60 socket~ about $6. (The rears are M14 triple square--better order in advance).

deilenberger

For the trivial price (less than $35) - DO get the VW tool - ie - pins. It makes the job much easier, you just raise the caliper up on the pins and it catches in a recess in the pin and stays there while to replace the pads. Once the new pads are in un-hitch it from the recess and lower it down. You never have to lift it, and you don't risk bending the hard brake lines that way. You're saving potentially thousands of dollars - it's worth spending a few bucks to make the job easier (and IMHO - better/safer.)

jay958

interesting, please direct me to where i can buy for "less than $35"?

it is officially called "

T10439, Brake Caliper Assembly Pins

d7101

Good luck getting these pins in Canada for less than 100 bucks, but i have done 2014 silver caliper pads and rotors without them, its' a breeze.

deilenberger

The link you provided has them for $37.39. Looks like they went up about $3 since I bought them 2 years ago.

deilenberger

I don't believe the silver calipers are "radial" mounted - so the pins wouldn't even work with those calipers, and you're correct - since they wouldn't work they'd be totally unnecessary.

Wrong on that - I went and looked.. even the silver calipers are radially mounted. The thing with the turbo calipers - they weigh about 30lbs each. They are the length of my forearm. The pins make it much safer to work with them, and since you're saving all the money DIYing - it seems reasonable to spend the less than $40* for the tools that make it easy to do.

* = price adjusted for inflation.

tgavem

d7101

Agreed, if you can find them for that price, crazy not to use them. For the folks up in Canada, they don't seem to be available for less than $100, plus shipping etc. Makes it slightly less reasonable