How do drum brakes adjust themselves

Changing brake shoes - function, diagnosis and installation instructions

Is your car losing braking power or making noises from the direction of the brakes? Then the brake shoes may be broken or worn. Fortunately, swapping these parts is quick and easy. Our guide reveals interesting facts about drum brakes and we show you how to change the brake shoes on your car yourself.

Structure and function of the drum brake

The drum brake is the forerunner of modern disc brakes. Today it is mainly used in cheap cars or off-road vehicles. The drum brake has a poorer braking effect than the disc brake, but is for it cheaper. Besides, she is less prone to pollution, because the brake drum is locked and no dirt can get into it.

The function is quickly explained: The Brake drums rotate with the axis. Inside are the Brake shoes on a Carrier plate. When braking, the brake shoes are from Brake piston pushed outwards and rub against the brake drum. The brake drums and brake shoes wear out due to the friction, and they need to be changed regularly. The wheel cylinder and the carrier plate, however, are not subject to any direct wear.

The brake pressure is generated by the brake cylinder and hydraulically by the brake fluid transfer. The expansion tank in the engine compartment is used to equalize the pressure and to read the brake fluid level. There are different versions for the car like the simplex brake, duplex brake or servo brake. These differ in the actuation of the brake shoes. However, changing the brake pads works identically for all of them.

Wear on the brake shoes

The Brake shoes are provided with friction linings, which wear out every time you brake. A self-adjuster adjusts the brake automatically so that the travel of the brake pedal or brake lever remains short. As a result, the drum brake works completely until just before the wear limit. The change is still inevitable and should not be postponed.

The durability is influenced by many factors. Differences in driving style and the terrain you drive on determine how long the brake shoes last. Straight stretches on the autobahn are gentler than slow city journeys. Depending on the driving style, brake pads hold the car 40,000 to over 100,000 kmbefore changing is necessary.

Symptoms of defective brake shoes

Worn brakes on the car are usually announced slowly. The most common symptoms of Defect of the brake shoes are:

  • extended brake pedal travel or brake lever travel
  • decreased braking performance of the car
  • Handbrake failure
  • more force required when braking
  • Vibrations on the steering wheel when braking
  • Grinding noises from the direction of the brakes
  • Lateral breakaway when braking
  • The brake warning light comes on

Check brake lining on drum brakes

The Covering thickness can be quickly check with the help of a peephole. This is a hole that is closed with a rubber stopper. You can use this to take a look at the brake shoes and assess whether it is necessary to change them. The TÜV also uses this method for the main inspection to check the brake shoes. Depending on the car, you may have to possibly briefly dismantle the wheel.

Worn brake drums or brake shoes adjust legal Problem. Due to the decreasing effect, the vehicle is no longer roadworthy and can Penalties and further difficulties lead with insurance. Replacing the pads therefore not only restores the safety of the car, but also protects against additional costs.

Step by step instructions - change the brake shoes on the car yourself

Your car's brake pads are worn out and need to be changed? Carry out the exchange yourself with the help of our DIY guide. Note: When changing parts of the brake, the procedure is always axis-by-axisto get an even braking effect on both sides. Never change a single pad, but always change all parts on the axle equally!

You will need the following to change the brake shoes on a car Tools and aids:

  • Jack or lifting platform
  • Set of socket wrenches
  • Torque wrench
  • screwdriver
  • Lever tool
  • Pliers, e.g. B. Combination pliers
  • hammer
  • brush
  • Optional: brake cleaner
  • Optional: special attachment for brake shoe springs

1. Preparation

Park the car on a level surface. Wait a few minutes after your last ride as the Brake drums a big heat develop. Release the handbrake when working on the rear axle. This would hold the brake drum in place and prevent it from being dismantled to replace the brake shoes.

To back up The car against rolling away and lift it up with one Jack or a lifting platform. Build that Wheel offto change the brake shoes on the car. To do this, loosen the screws or nuts on the outside of the wheel.

2. Expose the carrier plate and brake shoes

After dismantling the wheel there are depending on the type of car two optionsthat are only in the sequence distinguish. With variant one, first loosen the nut in the middle and then the cover. With variant two, the cover comes first and then the nut. After this step you should have a clear view of the brake shoes, the brake carrier and the wheel brake cylinder.

Many cars have a center Rubber stopper good to see. Pull this out with a screwdriver. Below is one central mother to the fore. This is with one Sapwood secured. Loosen the split pin and then the nut. Then the Brake drum cover dismantle. to leverage Loosen them with a screwdriver or loosen them with very careful hammer blows.

The second variant is the Cover the brake drum with a screw attached. This screw can be clearly seen. Solve this with the appropriate one screwdriver. You can then carefully pry or knock the cover out. Now loosen the rubber stopper and then the nut in the middle.

3. Remove the brake shoes

Make a note of the before swapping Position of the brake shoes and springs. Ideally, you can get a sharp one photo do. This makes it easier to install the new parts in the right place after the change.

The Brake shoes are through the middle Pens with a feather held. You have to do this unscrew by 90 °to solve them. At the same time, you need to hold the pins on the other side as they are movable. There are special attachments for this, but it also works with pliers.

The brake shoes can now be moved. You may also have to unhook a spring from the brake piston to change the jaws. By Fold out the jaws get to that Brake cablethat mostly on the inside is attached. Unhook it to completely remove the brake shoes.

4. Check and cleaning

Take the opportunity and examine The brake drum for fluid, especially in the Area of ​​the wheel brake cylinder. You'll find here brake fluid, this indicates a small leak in the wheel cylinder or the brake line. Eliminate this damage before proceeding with replacing the pads.

If everything is fine then clean the carrier plate before changing the jaws. Use a brush to remove the roughest dirt. Then check the carrier plate and the cylinder with the eye for major damage.

5. Install new brake shoes

If you have ordered a complete set of brake shoes for your car, these are often included Small parts contain. To deceive In this case, exchange used parts for new ones. Remove the missing parts from the old brake shoes and put the kit back together completely. Make sure that all clips and springs back in place so that the brake shoes and the self-adjuster function completely.

Now comes the last step in changing the brake shoes: the Installation. Just go here in reverse order in front. Hang that Brake cable again on and position The brake shoes. Then fasten them again with the pens and nibs. Take your photos on hand if you are unsure what it looked like before the trade.

6. Assembly and test drive

After changing the brake shoes assemble all other parts again. Reinstall the brake drum cover and nut. Replace the cotter pin with a new one. Finally, attach that wheel again and pull this with the Torque wrench firmly.

Now do a short one test drive to see if the brakes work again after changing the pads. Start with low speeds and check the brake carefully. Test Hand and foot brake levers. If everything works, do one more Braking at a typical speed out. Everything OK? Then that was it Switch the brake shoes of the drum brake successful!

Change the brake shoes on the car yourself

With our guide you can change the brake shoes of the drum brake in your car yourself. You can find the necessary tools in almost every hobby screwdriver's workshop. The cost of the brake shoes depends on the car 15 to 40 €. The time required to change is about an hour per axis.

Have the brake shoes replaced in the workshop

Of course, you can also have the brake shoes and brake drums changed in the workshop. The specialists replace the wear parts as required, axially or completely, and repair the brakes. But here you have to Total costs between € 100 and € 250 calculate when changing the brake shoes.

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