E89 Manually release handbrake calipers

[sgreen503]

Hello forum.
I own a 2009 Z4 E89. Recently my Park ((P)) light has been intermittently playing up. Sometimes releasing the handbrake, sometimes not.
A few days ago I attempted to release the handbrake, and although the red LED light went off on the button, the brakes didn't release. And haven't since. This also happened a year ago and I am aware this is a known fault with low battery triggering the issue.
So the battery is now fully charged and all other functions on the car are working fine. It's starts on the button. But the audio warning and ((P)) light are still displaying on the dashboard and it's not releasing.
My local mechanic says there should be a mechanical release for the brakes, and once I've freed them off, I can drive it to him for a ECU update, which should hopefully solve the issue. It did last time at least.
But I can't find any info on where the release button is, or if it's on the calipers themselves. I know on the X3 the mechanical 'pull' lever is in the boot, but does my Z4 have a similar set up?
Any info appreciated
Steve

 

[B21]

Electromechanical parking brake - emergency release

Necessary preliminary tasks:
Remove parking brake actuator on left and right


Important!
Secure vehicle against rolling, e.g. with chocks.


Using an 7 mm WAF Allen key (1), turn back brake caliper spindle in clockwise direction.

Turn back until wheel can turn freely.

Important!
Do not turn the spindle to the end stop.

At the end stop a fault code is set which will cause the system to shut down!

If this is the case, clear the fault memory



Note:
Startup after circuit interruption:
Switch on ignition.
Press brake button with brake pedal depressed.
The indicator lamp in the instrument cluster goes out as soon as the parking brake is released.




Removing and installing/replacing parking brake actuator

Necessary preliminary tasks:
Release parking brake
Turn off ignition

Important!
Switch off ignition at least 30 secs. before disconnecting the plug connection.


After installation, observe the following: switch on ignition and, using parking brake operating element, open parking brake once, close once and open again.

Disconnect plug connection (1).

Disengage cable from cable holder.


Release screws (1).

Installation:
Replace screws

Tightening torque 34 41 1AZ .


Take off holder (2).

Detach actuator drive (3) from brake caliper.


Installation:
Check sealing ring (1), replace if necessary.

Apply a light coating of brake fluid to sealing ring (1) before fitting.



Installation:
Carefully fit actuator drive until teeth engage and actuator drive rests flush on brake caliper.

If necessary, turn actuator drive slightly until bore and thread are flush.

 

[sgreen503]

Thanks B21 that's an incredibly clear set up instruction guide I thought this was going to take ages!
I'll try 1st thing tomorrow, much appreciated.
Steve

Electromechanical parking brake - emergency release

Necessary preliminary tasks:
Remove parking brake actuator on left and right


Important!
Secure vehicle against rolling, e.g. with chocks.


Using an 7 mm WAF Allen key (1), turn back brake caliper spindle in clockwise direction.

Turn back until wheel can turn freely.

Important!
Do not turn the spindle to the end stop.

At the end stop a fault code is set which will cause the system to shut down!

If this is the case, clear the fault memory



Note:
Startup after circuit interruption:
Switch on ignition.
Press brake button with brake pedal depressed.
The indicator lamp in the instrument cluster goes out as soon as the parking brake is released.




Removing and installing/replacing parking brake actuator

Necessary preliminary tasks:
Release parking brake
Turn off ignition

Important!
Switch off ignition at least 30 secs. before disconnecting the plug connection.


After installation, observe the following: switch on ignition and, using parking brake operating element, open parking brake once, close once and open again.

Disconnect plug connection (1).

Disengage cable from cable holder.


Release screws (1).

Installation:
Replace screws

Tightening torque 34 41 1AZ .


Take off holder (2).

Detach actuator drive (3) from brake caliper.


Installation:
Check sealing ring (1), replace if necessary.

Apply a light coating of brake fluid to sealing ring (1) before fitting.



Installation:
Carefully fit actuator drive until teeth engage and actuator drive rests flush on brake caliper.

If necessary, turn actuator drive slightly until bore and thread are flush.

 

[B21]

If you have ISTA or newTIS you too can be a hero!

 

[flybobbie]

Just replaced my rear brake pads and discs.
I used the Foxwell service brake function through the obd to release the brake pads.

When fitting the pads i couldn't push the pistons back.
I had to manually wind them back with the Allen key, so removal of motor still required..

So service mode seems to only release brakes, not position the adjuster to fully back position for pad replacement.

It would seem the service brake function is just an emergency release.

 

[RobbiZ4]

Take two wires, a simple 9V block battery and drive the motors to release and later on to narrow back.
Thats all U need.

 

[Busterboo]

Electromechanical parking brake - emergency release

Necessary preliminary tasks:
Remove parking brake actuator on left and right


Important!
Secure vehicle against rolling, e.g. with chocks.


Using an 7 mm WAF Allen key (1), turn back brake caliper spindle in clockwise direction.

Turn back until wheel can turn freely.

Important!
Do not turn the spindle to the end stop.

At the end stop a fault code is set which will cause the system to shut down!

If this is the case, clear the fault memory



Note:
Startup after circuit interruption:
Switch on ignition.
Press brake button with brake pedal depressed.
The indicator lamp in the instrument cluster goes out as soon as the parking brake is released.




Removing and installing/replacing parking brake actuator

Necessary preliminary tasks:
Release parking brake
Turn off ignition

Important!
Switch off ignition at least 30 secs. before disconnecting the plug connection.


After installation, observe the following: switch on ignition and, using parking brake operating element, open parking brake once, close once and open again.

Disconnect plug connection (1).

Disengage cable from cable holder.


Release screws (1).

Installation:
Replace screws

Tightening torque 34 41 1AZ .


Take off holder (2).

Detach actuator drive (3) from brake caliper.


Installation:
Check sealing ring (1), replace if necessary.

Apply a light coating of brake fluid to sealing ring (1) before fitting.



Installation:
Carefully fit actuator drive until teeth engage and actuator drive rests flush on brake caliper.

If necessary, turn actuator drive slightly until bore and thread are flush.

What a silly post.

 

[The.Analyst]

Electromechanical parking brake - emergency release

Necessary preliminary tasks:
Remove parking brake actuator on left and right


Important!
Secure vehicle against rolling, e.g. with chocks.


Using an 7 mm WAF Allen key (1), turn back brake caliper spindle in clockwise direction.

Turn back until wheel can turn freely.

Important!
Do not turn the spindle to the end stop.

At the end stop a fault code is set which will cause the system to shut down!

If this is the case, clear the fault memory



Note:
Startup after circuit interruption:
Switch on ignition.
Press brake button with brake pedal depressed.
The indicator lamp in the instrument cluster goes out as soon as the parking brake is released.




Removing and installing/replacing parking brake actuator

Necessary preliminary tasks:
Release parking brake
Turn off ignition

Important!
Switch off ignition at least 30 secs. before disconnecting the plug connection.


After installation, observe the following: switch on ignition and, using parking brake operating element, open parking brake once, close once and open again.

Disconnect plug connection (1).

Disengage cable from cable holder.


Release screws (1).

Installation:
Replace screws

Tightening torque 34 41 1AZ .


Take off holder (2).

Detach actuator drive (3) from brake caliper.


Installation:
Check sealing ring (1), replace if necessary.

Apply a light coating of brake fluid to sealing ring (1) before fitting.



Installation:
Carefully fit actuator drive until teeth engage and actuator drive rests flush on brake caliper.

If necessary, turn actuator drive slightly until bore and thread are flush.

What a silly post.

Why?

 

[Busterboo]

Because, if the person who asked the question could understand B21's answer, they wouldn't have needed to ask the question in the first place.

 

[The.Analyst]

Because, if the person who asked the question could understand B21's answer, they wouldn't have needed to ask the question in the first place.

I think you’ll find that those are the extracts from the official BMW workshop manual

 

[Busterboo]

Because, if the person who asked the question could understand B21's answer, they wouldn't have needed to ask the question in the first place.

I think you’ll find that those are the extracts from the official BMW workshop manual

Now that is a wonderful post.