Changing drum brakes is not difficult but requires the use of special tools and a little attention, and in return you won't have to pay a mechanic. This article describes the general procedure, but it's always best if you check your car's manual.
Steps
Step 1. Put on an asbestos mask
The work you are about to do involves the presence of asbestos dust, which is very dangerous. Use a special mask, not a paper one. Keep children and pets away from where you are working.
Step 2. Remove the hubcap and loosen the nuts
Lift the car with a jack and use supports.
- Never get to work on a raised car only with the jack. Blocks of wood or bricks are not good substitutes.
- Finish removing the nuts and take off the wheel.
Step 3. Spray penetrating oil on the wheel hub
Warning: a product like the WD-40 is not indicated
Step 4. Take the drum brake by the edges and pull it off
Move it around a little while you pull it off, it should make it easier.
Step 5. Note:
some drum brakes are held in place with screws. Remove them before removing the brake.
Step 6. Once removed, examine the brake
- If it is marked it should be refracted or replaced.
- Drum brakes have several springs and levers for self-adjusting brake and handbrake. They usually come in different colors, so take some photographs or a detailed drawing to help you remember where each part is before you take it all apart!
Step 7. Spray brake cleaner all over the mechanism
Remember that brake dust is asbestos and it is dangerous if breathed. Wear a mask.
Step 8. Compare the new shoes with the old ones
Make sure they have the holes in the same place.
Make sure the jaws are the same width
Step 9. Remove the brake
- Remove the return spring of the jaws;
- Detach the handbrake lever;
- Hold the shoe fixing pin from behind and remove the cotter pins;
- Open the brake shoes from the top and detach them from the wheel cylinder pins;
- Remove both jaws and the self-adjusting block as a whole;
- Put the old jaws on the ground in part to the new ones;
- Sometimes the anterior jaw is different from the posterior one. The one with the shorter trim strip usually goes to the front.
- Tilt the top of the jaws inward very carefully, so as to release the tension on the self-adjusting spring.
- Remove the self-regulating;
- Inspect and clean all the mechanical parts of the brake that you can reuse, check the damaged ones and replace them if necessary;
- It is recommended to replace all springs with a new set;
- The regulator should be unscrewed, disassembled clean and lubricated with a suitable product;
- Remove the spring and immediately hook it to the new shoes exactly as you removed it;
- Inspect the brake cylinder and replace if you notice any leaks.
Step 10. Rebuild the new brake
- The brake plates should be cleaned and lubricated on the moving parts and in the pins;
- Screw the self-regulator back on. One side will have a left-hand thread;
- Place the self-adjusting on the new jaws and open the top to tighten the spring;
- Put the brake shoes in place and insert the fixing pins into the right holes;
- Install the jaw springs;
- Attach the shoes to the wheel cylinder pins;
- Re-engage the handbrake lever;
- Install the return springs;
- Using a suitable tool, place the brakes in the "drum" so that they match.
Step 11. Check the new brakes with the photo you took earlier
If you see something different, start over.
Step 12. Put everything back as before
- Slide the new or refracted drum onto the wheel bolts;
- Screw in the bolts if they are present;
- Adjust the brakes;
- Reinstall the wheel;
- Adjust the brakes;
- Remove the jack supports;
- Lower the jack;
- Firmly tighten the wheel bolts and refit the hub cap;
- Repeat everything on the other side of the machine;
- [Bleed the Car Brakes | Bleed the brakes if you have replaced the cylinders;
- Take a road test to check the correct functioning of the brakes.
Advice
- Do not disassemble both sides at the same time. If you have problems you can look at the side you haven't touched yet and see where you are wrong.
- When you buy the brake shoes, also buy a new set of springs. It doesn't cost that much and it's worth having.
- Machine brakes can be very different from each other. These are just general steps based on an American automobile.
- Don't work on the brakes alone if you are not an expert. If you have to read how to take apart a wheel then you are not qualified to do such a job.
Warnings
- Never work on a machine supported only by the jack. Never, not even in an emergency.
- Buy the right tools.
- As soon as the drum is removed, do not touch the brake pedal. You'll push the piston out of the wheel cylinder and putting it back is a different matter.
- Be careful not to breathe the dust! A simple mask is not much use, asbestos powders are too fine.
- Don't start repairing your brakes on your own if you don't know how to do it, you don't want to start repairing a car here.
