How-To DIY: Parking Brake Disassembly/Rear Brake Pad Replacement

Ole1

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Jul 7, 2018
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long beach
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#21
Thank You Again for all the great info !!!
....
I just finished installing a new set of rear rotors and pads (actually, only one side so far ... I will take a couple pics on the other side today)
...
I have a couple questions/comments

Do you know what the torque specs are for the Parking brake motor, Caliper slider bolts, and caliper mounting bolts ?

Also, many ways to skin a cat (or change a set of rear pads on a model 3) .... I found it easier to leave the caliper slider bolts attached, and remove the parking brake motor, then retract the parking brake adjuster by turning it clockwise, gently, till it stops, then gently spreading the pads with a large screwdriver - just enough so that there would be enough space to put the new pads in place of the old ... Then, slightly loosen the caliper slider bolts and remove only the top one. And finally, just rotate the caliper away from the rotor - making it easy to remove and replace the pads.

After changing the pads, I rotated the caliper back, and re-installed the slider bolts - then removed the caliper bolts, set the caliper on the lower control arm (?), removed and replaced the rotor (with rotor hold down screw), and finally, with everything put back together and torqued, I re-connected the parking brake motor connector. Last, get into the car, apply brake, switch to neutral, and then into park, and listen to the parking brake motor re-adjust to new pads ..... Done.

I will take a few pics when I finish the other side later this morning ....
 

Mike

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#22
Hello friends!

Yesterday we had to replace our rear brake pads on our RWD Model 3. The looks we got at the Tesla Service Centre were funny, who the heck wears out their brake pads on an electric car?! The answer is Team MPP!

This DIY will be useful for anyone who needs to remove their rear calipers to replace their pads, rotors, or to paint their calipers.

Time required: 30-45 minutes

Difficulty: 2/5

Tools required:
- One helper
- 5mm Allen key/ hex bit
- 6mm Allen key/ hex bit
- Torque Wrench
- 21mm 1/2" drive socket
- 14mm wrench/socket
- 1/4" or 3/8" drive ratchet depending on sockets
- Floor Jack
- Jack stands

My apologies if the photos aren't amazing, I used my phone!

1. Loosen the lug nuts on the right rear wheel

2. Jack up the right rear corner of the car from the lift point, for safety place a jack stand or your wheel under the car



3. Remove the wheel

4. Prepare to unplug electronic parking brake - push the red clip away from you to unlock the connector



It will look like this



5. Now the important part: Have your helper get in the car. They must hold down the brake pedal, and place the car in N (hold the selector there for a few seconds). It is important to never touch the throttle during this process. When the car is placed in N, the parking brake motors will retract. Now you can unplug the parking brake motor. Once unplugged, place the car back in P, and safely exit the vehicle.

6. Okay, the hard part is over! Now it's time to disassemble the brakes. Use a 14mm wrench and undo the two caliper slider bolts



7. Remove the caliper, it will still be connected to the car via the brake hose. Be careful not to strain it.

8. Remove the electronic parking brake motor. You will need a 5mm allen key or hex bit. Be gentle with the motor, and be sure not to introduce any dirt or debris.



9. You did it! This is what you will be looking at, the next step is to safely retract the piston.



10. Insert your 6mm Allen key or hex bit into the exposed adjuster.



11. We need to apply gentle pressure to the piston as we turn the adjuster, I tried with my hands first, but I wasn't strong enough! We don't recommend using a piston compressing tool, it really doesn't need much pressure. We used channel locks, once again, very low pressure required, be careful not to mar any surfaces.

Rotate the adjuster clockwise, while applied steady pressure to the piston, it will retract smoothly and easily. Turn the adjuster until it stops. Don't force it!



12. Now we are ready to replace our pads. Remove them from the carrier, and replace them. They are labelled inside and outside, so there is no confusion. You may choose to use brake pad lubricant, we decided to forgoe that, since it will burn off at the track.

We compared the measurements of our old and new pads. The new pads were 8.5mm thick, the old ones were 4mm. We are going to the track in a few days, so we needed to make sure we have enough pad.







8.5mm isn't very much for a new pad, but with our powerful regen, it should last a very long time under normal operating conditions.

13. The parking brake motor has splines that go into the adjuster we used our allen key in. You may have to turn the adjuster a little so the parking brake motor lines up. The motor will be able to adjust for this later, so as long as you can install the motor, it will be fine. Clean off any dirt, then install the motor on the caliper, and tighten the 5mm bolts.



14. Install and tighten the 14mm caliper slider bolts

15. Now that everything is assembled, reconnect the parking brake connector, and engage the red locking tab.



The parking brake motor will do a full sweep to it's limits, adjusting to the new pads. Don't be alarmed by the noises!

16. Install and torque your wheel. You finished one side! Now all you have to do is repeat these steps on the other side!



Always pump your brake pedal at least 5 times after any work on your brakes, this will ensure the caliper pistons are no longer retracted, and the pads are contacting the rotors.

The Model 3 will automatically clear the error messages that popped up during this process.

There is no complicated bedding-in process for your new pads, just drive normally and try to avoid hard stops using the brakes for the first 100 miles.

That's it, enjoy!

- MPP Team
Thanks for this great procedure!

Question: I intend to do a simple, once a year "normal" lubrication of the caliper (sliders) in my LR RWD TM3 (as I have done for decades in all my daily drivers). Does the rear parking brake motor have to be removed from the caliper itself prior to normal, routine inspection and lubrication of the caliper sliders and pins?

Thanks.
 

Cintoman

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Joined
May 3, 2016
Messages
178
Location
Rhode Island
#23
Hey @MountainPass , I was planning on fully painting my calipers the "right" way...removing the parking brake motor, removing the pads, etc, so I don't get paint on anything else. My question is the following: since I'm not going to be replacing worn out thin pads with new thicker ones, would I have to use the 6mm Allen key or hex bit into the exposed adjuster and channel locks to push the piston back in? When I painted my front calipers last weekend, I didn't even need to use a piston retractor tool on the 4 pistons up front because the pistons didn't even move out despite being exposed open for a few hours while I painted the fronts. I was actually surprised they didn't even move a bit at all; I was able to slide the existing front pads back in with no problem. I would think the rears would be the same.

I'm thinking that if I can put the car in Neutral, then have someone unplug the connectors to the piston motors, then put the car in Park, I should be fine to remove the motors, remove the pads, paint them, and put everything back together without having to back the piston into the caliper.

Thoughts?

Thanks,
Cintoman
 

Cintoman

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Joined
May 3, 2016
Messages
178
Location
Rhode Island
#25
I used this guide to remove and fully paint my calipers. Process was very straightforward. But in my case, after putting the car in neutral and unclipping the parking motor cable connections, my car would not go into Park. It stayed in Neutral the whole time. When trying to press the P on the stalk, it would initially go to Park, but then several warning messages would come up (about parking brake being disabled), and it would then go back into Neutral. However, once I finished painting the calipers and put it all back together, all the warning messages disappeared as you noted, and have had no issues at all with the rears.

The only issue I had since I fully removed and painted the front calipers is that I have this CRAZY loud squeal when coming to a complete slow stop (reverse and forward)....just the last 1/2mph to 0 mph. Sounds as though I should have put some pad grease between the pads and the piston. But it's strange that they didn't have grease from the factory and weren't squealing until I removed them to paint the fronts.

--Cintoman
 

iChris93

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#27
When I swapped rotors on my car, I put it in service mode and had the front wheels chocked. This retracted the rear pistons for me, and kept the car from moving. Then I just unplugged the power to rear calipers until everything was back together.

Yeah only just found this post! :)
Is service tow mode?
 

iChris93

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#29
Yes sorry, Tow Mode. It will re-engage the brakes in about 20mins based on my experience; the unplugged one of course doesn't move but the other will have parking-brake-mode reestablished
Thanks! I didn’t think of that yesterday when doing the project alone and had to put a bag of fertilizer on the brake pedal.