Bosch CX Gen 4 - missing seal and ERROR 500

Hamina

E*POWAH Master
Mar 22, 2020
500
396
FIN
I would like to double check that should all Bosch CX Gen 4 motors have a white seal under the Bosch emblem? I got a new replacement motor from Bosch last summer. At some point the Bosch emblem got lost during the ride and back home I noticed there's no seal at all.

I'm a little afraid that the water has gotten inside the motor shell as I got couple times ERROR 500 that ended to no assistance and Purion shutting down.

Any recommendations what to do?

This is how it looks now
1714324017812.jpeg


This is what the old motor looked before sending back to Bosch
1714325004402.png
 
Last edited:

Bones

E*POWAH Elite
Subscriber
Apr 3, 2020
895
1,177
Harrogate
I would like to double check that should all Bosch CX Gen 4 motors have a white seal under the Bosch emblem? I got a new replacement motor from Bosch last summer. At some point the Bosch emblem got lost during the ride and back home I noticed there's no seal at all.

I'm a little afraid that the water has gotten inside the motor shell as I got couple times ERROR 500 that ended to no assistance and Purion shutting down.

Any recommendations what to do?

This is how it looks now
View attachment 139395

This is what the old motor looked before sending back to Bosch
View attachment 139398
I'd get InTouch with Bosch if I was you.
There's no point in putting silicone sealant into the hole if the motor has already got water in it.
It could be a different casing or they could have cocked up and you may be due another new motor.
 

Bearing Man

Ebike Motor Centre
Patreon
Sep 29, 2018
975
2,331
UK
I would like to double check that should all Bosch CX Gen 4 motors have a white seal under the Bosch emblem? I got a new replacement motor from Bosch last summer. At some point the Bosch emblem got lost during the ride and back home I noticed there's no seal at all.

I'm a little afraid that the water has gotten inside the motor shell as I got couple times ERROR 500 that ended to no assistance and Purion shutting down.

Any recommendations what to do?

This is how it looks now
View attachment 139395

This is what the old motor looked before sending back to Bosch
View attachment 139398
Sadly this used to be quite common and has now been addressed by Bosch with a new type of sticker. This is exactly what it looks like... a hole directly into your motor! You do need to contact Bosch because this motor will fail prematurely if any water at all has made it's way inside.
 

Hamina

E*POWAH Master
Mar 22, 2020
500
396
FIN
Okay, this doesn't sound too good.

I find it interesting that one would leave the seal out of the configuration for a motor that has big big risk of getting flooded or wet. I can't find the logic in it.
 

Hamina

E*POWAH Master
Mar 22, 2020
500
396
FIN
It seems that now the motor died finally. It gives the ERROR 500 immediately after switching the power on. Couple of days ago it still managed to work mostly.

I wonder if it's possible to buy US model and configure it to my Trek in Europe
 

E-MAD MALC

Active member
Subscriber
Nov 16, 2021
403
229
EAST SUSSEX
Okay, this doesn't sound too good.

I find it interesting that one would leave the seal out of the configuration for a motor that has big big risk of getting flooded or wet. I can't find the logic in it.
It could be possible that before they put that white patch over the hole they never cleaned it properly and when they put the bosch cover over that it's stuck to the patch and when the bosch cover fell off its taken that patch with it
 

Hamina

E*POWAH Master
Mar 22, 2020
500
396
FIN
I found the Bosch cover and it doesn't have the white seal attached. I don't believe that the seal would have gotten away at the same time. It looks like there never was a seal at all.

The good news (kind of): for as yet unknown reason the Purion doesn't give me anymore error after turning it on. The bike has stand still in dry storage for 5 days and I wonder if it would be the case that the humidity or water vaporized out of the motor frame. It feels a little strange and couple of test rides will show what is the real condition of the motor.

Bosch has not replied anything and the LBS has been quiet as they must be quite busy at the moment.
 

Bearing Man

Ebike Motor Centre
Patreon
Sep 29, 2018
975
2,331
UK
I found the Bosch cover and it doesn't have the white seal attached. I don't believe that the seal would have gotten away at the same time. It looks like there never was a seal at all.

The good news (kind of): for as yet unknown reason the Purion doesn't give me anymore error after turning it on. The bike has stand still in dry storage for 5 days and I wonder if it would be the case that the humidity or water vaporized out of the motor frame. It feels a little strange and couple of test rides will show what is the real condition of the motor.

Bosch has not replied anything and the LBS has been quiet as they must be quite busy at the moment.
On many of the earlier motors, there was no white sticker under the logo badge, so as soon as the badge feel off or started leaking, water would enter the motor.
If this is a small amount of water, it will just destroy the lower armature bearing. If it was a lot of water, this will be an expensive repair. Sorry to be the bearer of bad news but, you should find out in around 4 to 6 months, provided the circuit board keeps going.
 

alancube

Member
Sep 24, 2023
55
24
Essex
Reading this post I had to check my Cube and sure enough (thankfully!) I found a white nylon plug.
If the poster's seal has been missing from the word go surely that's covered under warranty?
 

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