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DIY repair: EPB_w053 - Parking brake did not release, EPB_w052 - Parking brake functions degraded

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Hi all,

I know it's been talked about a bunch over the past couple years, but I wasn't able to find a thread discussing the DIY repair method for these two errors.

Recently my 2015 S 85 started reporting the above two errors. After having my wife stand outside the car and cycling the car between P-D I was able to figure out the electric parking brake was no longer working on the passenger side. Some of you have experienced the same issue but were instead unable to release the parking brake; this should apply to those too.

After reading the threads here I found out the hard way Tesla doesn't just replace (or even offer for sale) just the electronic motor but instead opts to replace the entire parking brake caliper, sometimes on both sides to the tune of €1600-1800 for both sides!

Not wanting to settle for that (and throwing away perfectly good parts since just the motor is 'defective') I figured I'd take apart mine and see what I could do.

Below is a write-up of how I disassembled the motor and repaired fixed the EPB_w053 / EPB_w052 errors for a mere €37 in tools & RTV.

If you don't want to try fixing your own, or if it doesn't work, you can find the motor on AliExpress for ~$60. The part number is 40C07812.
Note that I haven't bought this and can't vouch for its quality, but I wouldn't be surprised if it's the exact same part. At least it looks the same and all the marking match up.


Tools required:
- A jack
- A jack stand (optional, but highly, highly recommended)
- A flat blade screwdriver
- Torx T25 bits (preferably long since there's not much clearance either side of the parking brake motor body)
- White lithium grease (I couldn't find any so I used ballbearing grease instead).
- Brake cleaner or degreaser and a (tooth)brush
Optional:
- Some RTV
- A razor blade or small plastic scraper


If you're attempting this I assume you know how to take a wheel off, so let's skip that and get to the good stuff. :)
Just make sure you've engaged Jack Mode prior to jacking up the car.


Here's my passenger side rear; main brake caliper on the left-hand side of the picture and the parking brake caliper on the 2 o'clock.
The electric parking brake motor is bolted into the back of the caliper.
At this point hose down the motor with the brake cleaner or degreaser where it bolts into the caliper and scrub the grime off of it to prevent it from falling into the caliper later on.

1.jpg




The first bolt is on the left-hand side, accessible from the top. You'll need to feel around a little. If at this point you can still feel some crud in the bolts, get out the brake clean again and spray into it so your torx bit makes good contact.

If you strip out these bolts there's no other option but to take the whole caliper off. So take your time, there's only three of them, all accessible from the top.
2.jpg



The second bolt is right in the center. Can't miss it.
3.jpg


Finally the third and last bolt is on the right. It's not too hard to find.
4.jpg


Unfortunately I didn't take any photos of the next step but with those bolts removed the EPB motor should come off easily.
Before you start yanking on it remember the plug is still attached. To release the plug take your flat-blade scewdriver and push against the red tab with a reasonable (but not plastic-breaking) amount of force. Now try to wiggle the connector off. If it won't come off, light up the black plastic 'flap' and try again.


You should now have the EPB motor disconnected. At this point I'd recommend bringing it inside (if your wife lets you).
Start by removing the c-clip that surround the area where the motor bolts into the caliper. There's not too much strength on this clip; I was able to get it off using two flat-blade screwdrivers in opposite direction. Engage safety squint in case it flies off.

There should also be an o-ring here. Take it off as well.

5.jpg



Now remove the two remaining torx bolts. Again T25's.
6.jpg


Before you start separating the two halves make a mark so you know how it lines up come reassembly.

Now it's time to split the EPB body. Start at #1 (below the metal 'plate' that's sandwiched between both halves).
Once that's loose you can split #2 but you only pull it up enough so you can see / clean inside it, there's some resistance there which I believe is the wiring for the plug up top so be careful.

Note: keep the EPB motor with plug facing when you take it apart or else the gears may fall out (not too big of a deal, they only go back in one way).
8.jpg


With the halves separated you'll end up with this. Note the flakes of salt that came off of mine as soon as I opened up.
Now it's time to get cleaning. Avoid gauging the surface; the smoother the surface, the better the seal you'll have going forward.

I'd recommend laying parts out in the order they came out, in the orientation they came out.
If you're reapplying grease, clean off all the old grease off the gears and surrounding surfaces before applying the new grease.

If your o-rings are still flexable (mine were) clean off the salt/crusties off of them and apply a light coating of grease so they continue to stay flexable.
Since the most salt was by far found in this part of the EPB motor I decided on running some RTV around the outside where the o-ring goes to help it seal better.
If you want to do this is up to you, but I figured (when applied sparingly!) it can't do any harm and clearly the old o-ring didn't seal 100% anyway.

7.jpg





That's it! Make sure you reassemble it the same way, don't forget any parts like the c-clip and, if you applied RTV, now is a good time for a coffee break to give it some time to set up.

In order to prevent the gear from engaging I'd recommend bolting the EPB motor back in place and *then* plugging the connector back in.
Once complete, cycle from P-D a couple times. The error should now have cleared. If not, either you didn't do the right side or the EPB motor is beyond saving. They're up for sale on AliExpress but I haven't tried them so your mileage may vary.
 
Anywhere other than Aliexpress these motors can be purchased? Aliexpress takes weeks to get here. Would like to find a vender that has reasonably quick shipping. Wish they were sold on Amazon.
Unfortunately Tesla only sells them as part of the entire emergency brake calliper. Not sure why they don’t sell them separately.
 
Anywhere other than Aliexpress these motors can be purchased? Aliexpress takes weeks to get here. Would like to find a vender that has reasonably quick shipping. Wish they were sold on Amazon.
Unfortunately Tesla only sells them as part of the entire emergency brake calliper. Not sure why they don’t sell them separately.
Yeah, unfortunately I only found them on Ali. I find it slightly upsetting as well Tesla only sells the entire assembly, both for cost reasons but also that I end up throwing out perfectly usable parts.

You could try cleaning the current motor while you've got a new one on order.

Maybe I'll order a couple of them and put them up for sale to help out fellow owners in Europe..
 
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What is worst case if you take off the parking brake motor and it is beyond saving? Could you drive the car to dealer or is it too risky that car would roll while parked? Reason i ask is Tesla wants to send a flatbed tow truck to pickup car which will be atleast $500 just for the tow. I'd sooner just drive it there if i can't get the actuator to become un stuck.
 
I had done the same process with 2015 Model S 85D. I even tried to remove the light coloured cap at the opposite end of the motor to access the internals. Learned the hard way, all the plug wiring internally is spot welded to tabs and will not remove easily. Epoxy put the cap back on and decided just to grease the gears.
I found the plug connector was filled with wet sand, somehow over the years and winters it finds it way into the plug housing.
This was a year ago, I am stating to see the same message again, perhaps from the opposite side. Not sure if there is a way to interpret the error codes to which side of the car is at fault. Likely just need a good set of ears, or stand outside and engage summon off and on to hear the activation up close.
 
So got the wheel off my 2017 MX and i definitely have the integrated parking brake. I see there is a motor/actuator driving this as well but unsure if this can come apart like in the older models. Does anyone have a tutorial on this? i see two bolts that seem to be holding the actuator onto the caliper and a wiring harness. Here is a picture of the part from the Internet. Welcome throughs before i try to disassemble (hate to screw the main brakes up)

GetProductPicture

R.ecd4654b1321e9262ed0d71432e0c1f2
 
8 year old 85D with 110000km. Decided to pull the left rear park brake motor.
What a fair-weather part, water gets into the seals far too easily. Lots of crud to scrape off, then clean and grease gears, then re-seat the o-rings in some silicone grease.
 

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LOL. Did you just do this for fun? Were you board? Or was yours acting up?
It was acting up. The park brake on the Model S is a pretty easy access because of its' location. I just cleaned and lubed then pair last fall and wondered why I was having error codes again.
Both electric brake motors show a lot of water ingress and corrosion...very poor design. These motors sit horizontally and are subject to water sitting on the seams. I wonder about some preventable sealing of the seams to keep the water out.
Ultimately in the wet weather, these electric park brakes have a finite life span much shorter than the life of the car.
 
Hadn’t been mentioned here but it may be relevant to get a stuck park brake free.
There’s two types of park brake mode on my Model X, the first is just push the park button at the end of the stalk when I park, and the dash shows the park symbol in grey I think. I use this 90% of the time.
The second is to push and hold the park button for 2-3 seconds. You can hear a different sort of actuation sound so I imagine the calliper is clamping down a little harder.
To release a stuck Park brake I have cycled between Drive and the heavier Park brake, then drive, then the normal brake and it frees the brake and the error disappears.

I do intend to do the maintenance above, but maybe this trick will get someone else’s park break unstuck if it happens to them.

FWIW, mine always gets stuck on the same driveway which has just a very small nose down angle perhaps 3 degrees. Happens easily 50% of the time I park there and on no other places that I take the car.
 
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It appears the piston screw shaft was dried out or corroded. Wasn't able to get it apart but there's a set screw hole that allowed me to pack some grease and it's moving freely now.
The opposite side wasn't acting up but I lubed it since I had everything set up.

P.s. the set screw is a torx one size up from the solenoid screws.
 
Last edited:
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Reactions: hydro
Hi all,

I know it's been talked about a bunch over the past couple years, but I wasn't able to find a thread discussing the DIY repair method for these two errors.

Recently my 2015 S 85 started reporting the above two errors. After having my wife stand outside the car and cycling the car between P-D I was able to figure out the electric parking brake was no longer working on the passenger side. Some of you have experienced the same issue but were instead unable to release the parking brake; this should apply to those too.

After reading the threads here I found out the hard way Tesla doesn't just replace (or even offer for sale) just the electronic motor but instead opts to replace the entire parking brake caliper, sometimes on both sides to the tune of €1600-1800 for both sides!

Not wanting to settle for that (and throwing away perfectly good parts since just the motor is 'defective') I figured I'd take apart mine and see what I could do.

Below is a write-up of how I disassembled the motor and repaired fixed the EPB_w053 / EPB_w052 errors for a mere €37 in tools & RTV.

If you don't want to try fixing your own, or if it doesn't work, you can find the motor on AliExpress for ~$60. The part number is 40C07812.
Note that I haven't bought this and can't vouch for its quality, but I wouldn't be surprised if it's the exact same part. At least it looks the same and all the marking match up.


Tools required:
- A jack
- A jack stand (optional, but highly, highly recommended)
- A flat blade screwdriver
- Torx T25 bits (preferably long since there's not much clearance either side of the parking brake motor body)
- White lithium grease (I couldn't find any so I used ballbearing grease instead).
- Brake cleaner or degreaser and a (tooth)brush
Optional:
- Some RTV
- A razor blade or small plastic scraper


If you're attempting this I assume you know how to take a wheel off, so let's skip that and get to the good stuff. :)
Just make sure you've engaged Jack Mode prior to jacking up the car.


Here's my passenger side rear; main brake caliper on the left-hand side of the picture and the parking brake caliper on the 2 o'clock.
The electric parking brake motor is bolted into the back of the caliper.
At this point hose down the motor with the brake cleaner or degreaser where it bolts into the caliper and scrub the grime off of it to prevent it from falling into the caliper later on.

View attachment 903994



The first bolt is on the left-hand side, accessible from the top. You'll need to feel around a little. If at this point you can still feel some crud in the bolts, get out the brake clean again and spray into it so your torx bit makes good contact.

If you strip out these bolts there's no other option but to take the whole caliper off. So take your time, there's only three of them, all accessible from the top.
View attachment 903997


The second bolt is right in the center. Can't miss it.
View attachment 904002

Finally the third and last bolt is on the right. It's not too hard to find.
View attachment 904003

Unfortunately I didn't take any photos of the next step but with those bolts removed the EPB motor should come off easily.
Before you start yanking on it remember the plug is still attached. To release the plug take your flat-blade scewdriver and push against the red tab with a reasonable (but not plastic-breaking) amount of force. Now try to wiggle the connector off. If it won't come off, light up the black plastic 'flap' and try again.


You should now have the EPB motor disconnected. At this point I'd recommend bringing it inside (if your wife lets you).
Start by removing the c-clip that surround the area where the motor bolts into the caliper. There's not too much strength on this clip; I was able to get it off using two flat-blade screwdrivers in opposite direction. Engage safety squint in case it flies off.

There should also be an o-ring here. Take it off as well.

View attachment 904004


Now remove the two remaining torx bolts. Again T25's.
View attachment 904005

Before you start separating the two halves make a mark so you know how it lines up come reassembly.

Now it's time to split the EPB body. Start at #1 (below the metal 'plate' that's sandwiched between both halves).
Once that's loose you can split #2 but you only pull it up enough so you can see / clean inside it, there's some resistance there which I believe is the wiring for the plug up top so be careful.

Note: keep the EPB motor with plug facing when you take it apart or else the gears may fall out (not too big of a deal, they only go back in one way).
View attachment 904009

With the halves separated you'll end up with this. Note the flakes of salt that came off of mine as soon as I opened up.
Now it's time to get cleaning. Avoid gauging the surface; the smoother the surface, the better the seal you'll have going forward.

I'd recommend laying parts out in the order they came out, in the orientation they came out.
If you're reapplying grease, clean off all the old grease off the gears and surrounding surfaces before applying the new grease.

If your o-rings are still flexable (mine were) clean off the salt/crusties off of them and apply a light coating of grease so they continue to stay flexable.
Since the most salt was by far found in this part of the EPB motor I decided on running some RTV around the outside where the o-ring goes to help it seal better.
If you want to do this is up to you, but I figured (when applied sparingly!) it can't do any harm and clearly the old o-ring didn't seal 100% anyway.

View attachment 904006




That's it! Make sure you reassemble it the same way, don't forget any parts like the c-clip and, if you applied RTV, now is a good time for a coffee break to give it some time to set up.

In order to prevent the gear from engaging I'd recommend bolting the EPB motor back in place and *then* plugging the connector back in.
Once complete, cycle from P-D a couple times. The error should now have cleared. If not, either you didn't do the right side or the EPB motor is beyond saving. They're up for sale on AliExpress but I haven't tried them so your mileage may vary.
Hell everybody, this Is my first post.
I want to share my experience because I had the same problem.
I really hope I might help somebody to save 1500+$
Suddenly the parking brake on the passenger side didn't release anymore.
Foto
I've tried to repair the part as described in this post.
Btw, be careful to unscrew the right screws as I was mistakingly unscrewing at first the wrong one and the motor didn’t come off right away and i risked to brake a part.
Foto
Sadly I wasn't successful, even I could disassemble it , clean it very well (it looked even worst than yours Xiomax) and reassemble it. Before I tried put it back, I was checking if the motor was rotating (to engage and release the brake) by connecting the electric plug and engaging/disengaging the parking brake. It did actually work, but at the end of the installation I got the same error as before.
Foto
Ok, I thought, it was somehow broken but I didn’t get why
So I decided to order the part 40C07812 from Aliexpress as suggested (I actually bought 2 pieces, just in case ;-) for 55$ each) and it arrived in 15 days!
Foto
I mounted it 3 days ago and it’s still working! Happy me and my wallet!
3x Foto
BTW: Did you know Tesla Service in Switzerland is getting wopping 235$ an hour ? Crazy isn't it?
I wonder how it costs in the US...
 

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