coulter

Just got a chance to do the rear brakes on my 2017 Panamera 4 (971). Everything seemed to fall in place, no idea why dealerships charge what they do for this job. If you've done brakes before, I think you can handle it. Thought I'd give a short write up as there's not enough DIY content here. Obviously, do this at your own risk, I'm not a pro and this is not all inclusive.

I had mentioned in previous posts, the brakes squealing was driving me crazy. The pads looked like they had some life left, and Porsche claims squealing brakes are supposed to be that way, so I as worried me replacing them would do nothing. But it really became clear as I was taking them out, the lack of lube anywhere was why they were screaming. They were dry as a bone and just pulling them out made the noise. They must come from the factory that way, fairly sure these were the original pads. happy to report squeal is gone after this job. If you really wanted to just address the squealing and not replace the pads, I think you could pull the caliper off and simply lube various pressure points (specifically the guide pins) and you would resolve the issue. My pads though were about 70% gone, so I decide to just replace.

The biggest challenge on doing these is the wear sensors, Porsche really made these a challenge to remove and install, mostly because there's a sensor on each side of the pad (usually it's just one) and access is limited once the pads are installed. Count on buying new sensors (2 sets total for the rear), do not attempt to do the job unless you have new ones in hand. They're like $40 total, $20 each. I'm not recommending this, but if you say just say tied the sensors off and didn't reconnect to the pads, this job just became 90% easier. But fortunately, I was able to reconnect. But I almost just tied them off. The trick is, route the new wire through the caliper first, connect to the brake pad on the outside one first, then put the outside pad in. Then install the inner pad, then connect the sensor to the inner pad. It's one of those things where after you do it once, it's way easier, but all of this easily added and extra 1-2 hours to the job figuring it out.

I added some pics, I'll probably come back and make some edits.

Here are the pads and sensors I ordered. In addition, I purchased new caliper bolts as they are recommended. Got all of them from Pelican Parts. I recommend them. My understanding is Textar is the the same exact as the Porsche as they are the OEM, it's just not in a Porsche box. Pelican lists PEX as the OEM for the wear sensors.




I put the car in "jack mode" on the infotainment screen.

I had a rectangle shaped jack adapter like this one, it was for a BMW X5. The larger sized ones for BMW work on the Panameras. I had to make a return as the adapter I originally purchased was slightly too small.



It fits in the slot at the jack points.



Jacked the rear up on the outside (I also put a secondary jack in the appropriate spot)



This is the security adapter needed to unbolt one of the wheel bolts, it should be under the hatch cover where the emergency roadside kit is.


Remove wheels. Get a small bucket or box so when you unbolt the caliper, you can rest it on the box nearby. You don't want to let the caliper "dangle".

Unclip the brake sensor harness first. You rotate it so it slides out of the bracket. A little tricky. You need to do this in order to pull the caliper away.




Unbolted these two Torx bolts (T-55) for the caliper.



Removed caliper, set on platform. I leave the old pads in and use a brake pad spreader before removing pads.




Removed pads, I found removing one at a time made it easier. Where I found the "squealing" coming from was these guides. I made sure to both clean and lube these contact points. I used ceramic synthetic grease from Permatex.




Route sensor wires through caliper, first connect outside pad to sensor, then place pad into caliper. Place inner pad into caliper, then connect pad sensor clip through narrow opening. This is the most difficult part of the job (imo). Once you figure it out though, much easier the next time. I suggest taking pics before doing it. I simply couldn't get good photos to illustrate. The main problem is the pigtail to the vehicle harness is too large to go through the caliper, it can only go one way. And access to connect pad sensor is difficult once pads are in place. Also, doing one pad at a time is easier because of the pad clip tension.




Rebolted caliper into place with new caliper bolts (T-55) , torque to 63 ft lbs. Reconnect wire assembly to bracket and pad sensor to vehicle harness. One thing to be cautious about, brake cleaner will take off the "Porsche" imprinted logo, so be careful where you spray it.


Bolted wheels back on. Torqued 19mm bolts to 120 ft lbs. I find this tool VERY handy for putting wheels back on, you screw it in one of the threaded holes and then slide the wheel through it. Allows the wheel to be properly positioned while adding the other bolts. Much easier than trying to hold in proper position and then screwing in.




When you get back into the car, take vehicle off of "jack mode". Make sure you pump the brakes SEVERAL times before taking out of park to make sure pads are in the proper position to grab the caliper.

I could now do this job in under 2 hours, but this took me closer to 4 hours because of the pad sensors. I bedded the brakes, and the car has zero squeal. I did not replace rotors as I had zero pedal pulsation and in my experience, rear rotors rarely need to be replaced. When I do front brakes, I almost always replace rotors. Very happy with the job.

Any questions, happy to answer them or give any clarification.

chassis

Are there two wear sensors per axle (1 per wheel) or one per axle?

coulter

It's 1 "set" or package per wheel, and in that set is two sensors. Each pad has a sensor. It's all connected as one ,continuous unit per wheel.

So you when order, you would say you want "2" units to do the rear.
4 units total (2 for the rear, 2 for the front) for the complete car. The front sensors are slightly different, longer.



You can reuse sensors, but what I found was it was very difficult to remove without damaging because you can't really get to the sensors inside the caliper.

The last car I did (Lexus) only had one sensor per wheel, which made installation way easier.

E39Nutz

Well done. Your stock pads are pretty low already. Good time to replace them. The sensor gets a bit brittle over time, part of the backing chipped off when you try to pry them out. Having a new set on hand makes this job efficient. I lubed all the contact points that the pads will have movement. Mercedes make (or rebranded) a good brake paste that I have been using for many years. Braking should be dead quiet. It’s a load of BS from Porsche.

VikingPorsche

Great write-up, thank you!
Did you order original caliper bolts and do you have the part numbers for these?

I've done some research and for a '18 E-Hybrid Sport Turismo with 390mm and 365mm slotted brake discs these are the part numbers (original Porsche):Front left disc: 971615301J
Front right disc: 971615302J
Rear left disc: 971615601J
Rear right disc: 971615602J

Pads kit front (both sides, 4 pads in total): 971698151T (old part nrs 971698151D and 971698151F)
Pads kit rear (both sides, 4 pads in total): 971698451L (old parts nrs 971698451A and 971698451H)

Rear sensors (1 pcs per wheel): 971907637A
Front I don't know yet.

chassis

Please answer this question: how many wear sensors on the rear axle?

Axle = a pair of wheels laterally opposed.

Your post quoted above conflicts with post #5.

Marcus13190

Thanks for your Diy.

coulter

Can you point out the contradiction so I can edit it?

You buy one package per wheel. Inside the package is one complete assembly. On this wire assembly are 2 pad sensors and a pigtail, all connected.





I don't like the term "axle" because there's 4 "axles" on the Panamera and that can be confusing. So I use "front" and "rear".

coulter

This was the part number for the rear caliper bolts
Brake Caliper Bolt (12 X 85 mm)
Part #: 9A7-007-585-00

They were Porsche brand, around $4 per bolt.

Norge911

Did you have to move the brake line or sensor brackets?

if yes, I didn’t see in above. Also, those little bolts can be a pain. Suggest to replace with bracket stud kit.

https://tarett.com/products/brake-bracket-stud-kit-bbsk

coulter

No, at least for the rear, no brackets needed to be unbolted for access. The pigtail assembly slides out of the bracket and is then unclipped.

chassis

How many sensors are required for the rear brakes? Rear brakes = left + right. You have not answered the question.

Regarding the term "axle", the big boys in the auto industry use this term globally and without exception. An axle is a pair of wheels, laterally opposed.

There are not 4 axles on a Panamera, unless Porsche has introduced a new model with one more axle than the G-Wagen 6x6.

coulter

I've answered your question several times. I'm done trying to explain this to you, there's either a language barrier or you are on the spectrum. Either way, you're on your own figuring out how many sensors. No one else seems to have this question.

And there are 4 axles on the AWD Panamera, to say how many sensors per axle just makes things even more convoluted.


Please, for the sake of everyone's safety, don't attempt to work on your own brakes if you can't figure out how many sensors to buy after reading this thread.

E39Nutz

Hmmm, only two axles for the Panny. Each caliper has a sensor, so 2 front and 2 rear.

chassis

2 sensors per axle, 1 sensor per wheel, 4 sensors per vehicle. That makes sense.