How to fix E65 E66 BMW 7 Series Parking Brake Actuator Failure – Plastic Gears vs Metal Gears
Standard intro – “Just rolled into the shop…”
We had a client come in with a parking brake that was staying stuck on. This obviously was causing all sorts of issues:
- It was dangerous as the parking brake was applied at all times – even while driving around, changing the driving dynamics of the vehicle.
- It was causing aggressive wear and tear on the parking brake shoes and rear brake disc. That would have destained the brake shoes, and would have spoilt the vehicle’s appearance.
- It was causing the parking brake active warning light to stay illuminated while driving – bringing undue stress on the driver. (We all hate ignoring those dash lights!) If you see this we highly suggest towing the car to avoid further damage to the parking brake system.
Upon inspection we discovered that the original gears in the actuator are plastic. Over time the plastic becomes brittle and cracks causing the unit to fail. As a result the actuator was unable to turn the gear and release the parking brake.
Here we have the trunk of the BMW 745 Li open. We had to remove the spare and the liner to access the actuator.
Here’s a close up of the recess where we removed the actuator.
Here’s the Actuator itself (with the gears removed.
Here’s the original gear. It turns like a corkscrew tightening and loosening the parking brake cables. You can see the plastic gears chewed themselves up and broke.
Now here’s the special part. Using a combination of ingenuity, experience, and a career building strong connections (read Google search), our technicians not only found a fix that cost our client less than replacing the whole unit, but less than the standard plastic replacements. On top of that the metal gear will last much longer than any plastic replacements. Hopefully meaning this issue is fixed for good!
Here’s a comparison of the plastic and metal gear pieces.
We’d love to hear your thoughts on the modernization of systems that may not need updating. Like the electronic parking brake with motors and gears vs. a standard lever actuated parking brake. Also, what (if any) “better than OEM” replacements have you found?
hi mate can you please tell as how to reset Parking brake on e65 2004 730d
my case is impressive
i see yellow light “P” and mi parking brake not working, when we clean the fault with diagnostic it’s working properly till i switch off the engine
and then it’s malfunction again
Hey Georgi, thank you for reaching out. Like some of the other comments, we can’t really troubleshoot remotely. We’d have to see it in the shop – however I’m keeping your comment live in case someone has had the same issue. If you’re in SoCal and would like to have it checked out, give us a call.
I had the plastic gear replaced with metal gear but light only goes of for short period and h brake also only work for short period. Not sure whats going on.
Frank, sorry to hear you’re still having issues with the hand brake/emergency brake. There’s not to much we could do without checking it out in the shop – feel free to give us a call if you’re in the area and we could get you in to check it out for you.
Gotta love finding a great solution! I just replaced mine as well with a full metal gear…but, my dash light didn’t go out and the OBDII doesn’t show a code/error that can be cleared. How did that process work on this vehicle?
Stefanie, thanks for reaching out, but this is something we’d likely have to look at to help with. In this case the light cleared when we were done so it didn’t require any extra troubleshooting.
the light and error codes cleared all by themselves???
Tom – good question. We always clear faults after a repair and I should have been more specific. We cleared the faults and all warning lights stayed off. So in this case it didn’t require any further troubleshooting.