If your parking brake is not functioning properly and it is having a hard time holding the car in place, you may only need to adjust it rather than replace everything. Fortunately make an adjustment is a relatively easy process. Here are the steps:
Over the years your car may have been serviced by multiple people including previous owners and this can lead to parts replaced with different size fasteners and hardware including the type of fasteners used on the tie rod ball joints. The sizes of the nuts and bolts we give may be different from what you have so be prepared with different size sockets and wrenches. If something is different on your vehicle please let us know and share your info to help other users. If you have any questions or comments or even a different procedure you would like to share please leave it below and please include your vehicle information.
There is an adjustment mechanism between the parking brake shoes that can be set to compensate for the wearing of the parking brake shoes. To adjust this mechanism, you must first raise and support your vehicle. Please see our article on jacking up and supporting your W123 for more information. With the car safely supported, remove the rear wheels. There is an adjuster on both rear wheels.
Note: If you cannot get the parking brakes to work with these adjustments then it is probably time to replace the shoes. Please see our article on replacing your parking brake shoes for more information.
Start by rotating the disc or rotor until you can see the adjustment wheel. You will need to shine a flashlight in the stud hole (red arrow) until you see the spindles on the adjusting mechanism. While you do not need to remove the rear rotors or discs to do this, you will be doing it "blind," as you cannot see the adjuster while working with it. The two parking brake shoes use the inside of the rotor as a brake drum. At the top of the two shoes is an adjuster that basically separates the shoes. It can be adjusted in or out by turning the spindled-wheel on the mechanism. You will need to turn this sprocket clock wise to expand the brake shoes. The best way to do this is to make sure the parking brake is off and try and turn the rotor by hand. You will want to adjust the tensioner until you can feel it grabbing the rotor. Once the shoes are grabbing the rotor, back off the adjustment so the rotor just spins free. Now apply the parking brake and you should be good. Make sure you do both wheels, so that you have maximum braking power and so the shoes wear evenly.
Here is what the adjusting mechanism looks like with the rotor off. You can see how the screwdriver enters through the stud hole and engages the spindles (red arrow) of the mechanism to turn it. You do not need to remove the rotor to perform this job though.