Can Brake Drums Be Relined?

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On a general note, there are two types of braking systems in common use: the hydraulically operated drum brakes and secondly, the disc brakes.

A brake drum is a heavy metallic covering that is fitted over an automotive brake assembly and which is usually attached to the axle too.

It is primarily used in a drum brake system in which brake shoes forcefully push against it to slow down or stop the vehicle.

The brake drum is attached to a rotating shaft or wheel against which the brake shoes or bands act. Specifically, the inside surface of the brake drum must always be smooth and uniform for the effective function of the brake system.

A hydraulic system forces the brake shoes against the internal surface of the brake drum which will slow down the vehicle and ultimately stop it altogether.

This system of brakes consists of hydraulic wheel cylinders, brake shoes, in addition to the drum brake itself.

A brake drum can reline. This happens when the hydraulic system which is operated by pressing on the brake pedal is forced against the drum itself.

As the brake shoes are forced against the brake drum, immense friction is generated which in turn gives rise to extreme temperatures.

This temperature can cause the metal components of both the drum and the brake shoes to become extra malleable.

This malleability can cause the drum to go out of round or distorted out of shape. Similarly, because of this excessive temperatures, materials from the brake shoes can get deposited on the surface of the drum which causes further roughness on the inner surface of the drum.

Progressively, the internal diameter of the brake drum widens while the thickness of the brake shoes reduces.

Consequently, you may have to upgrade to bigger brake shoes until such time when the drum will have to be replaced altogether. So, yes, a brake drum can be relined.

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What causes brake drums to be relined?

Generally, a brake drum relines due to the excessive temperature that is generated in the braking system.

This high temperature is capable of making the brake drum much more malleable. It is because of this malleability that the drum may go out of round or become disfigured and uneven.

To counter this rough or uneven inner surface of the drum, some metal on its inner surface must be scrapped with the aid of a brake lathe to restore its smoothness.

Other factors that can cause your brake drum to reline easily include your driving attitude as well as the conditions of the roads you ply.

Poor inspection and regular maintenance of the braking system can also cause your brake drum to reline regularly.

Therefore, it is highly advisable that you subject your car to regular maintenance and also use the brakes properly too.

Also, it will be good to buy reliable and excellent brake drums for replacement at all times. Another factor that contributes to your brake drum getting relined is the deposition of the material of the brake shoes onto the inner surface of the drum.

Whenever the temperature of the brake rises tremendously, some of the friction materials on the surface of the brake shoes may separate from it and get deposited onto the inner surface of the brake drum, thereby causing more roughness and poor braking performance as well.

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How do brake drums reline?

Brake drums reline when they become rough or uneven in their inner surfaces mainly as a result of the deposits of materials from the brake shoes that constantly rub against them or the disfiguration they suffer due to the excessive temperatures in the braking system when in use.

The combination of these factors will eventually make the inner surface of the drum rough or corrugated, and because of this, you may have to restore the internal surface of the drum before it can work effectively.

Whenever the diameter of the brake drum increases, a space or gap exists between the drum and the brake shoes.

It is in this gap that the brake shoes move at random, and the movement of the brake shoes is what generates the noise heard when braking the vehicle.

Does the relination affect brake drums?

Yes, reclination significantly affects the brake drum. For instance, as the internal diameter of the drum increases over time, you may have to keep upgrading to bigger brake shoes so that they will be able to make contact with the internal surface of the drum.

This can continue until such a time when you can no longer resurface the drums, and at this point, you can only replace the drums entirely.

The process of resurfacing the inner surface of the drum entails scraping and smoothing it. This makes their diameter to become wider while the thickness of the brake shoes decreases.

If you fail to change the brake shoes to a bigger set, whenever you press on the brake pedal, there will be a space between the drum and the brake shoes.

Due to this space, the brake shoes can move either up and down or left and right whenever you press the brake pedal.

This is what causes the pulsations or vibrations you feel transmitted in the brake pedal. This will significantly reduce the effectiveness of your braking as well as increase your braking distance with dire consequences. So, yes, the reclination of brake drums affects them in many ways.

How often do the brake drums reline?

How often your brake drums reline depends on several factors. One, it depends on the quality of the drum itself.

Two, it also depends on your driving and braking habits as well as the condition of the roads you frequently ply.

However, despite all these factors, a good brake drum can last for as long as 200 000 miles. Although in some situations the brake drums can wear out sooner than this due to worn-out internal components that cause more strain on the drums.

What happens when a brake drum is relined?

Several things are bound to happen when a brake drum relines. One, when your brake drums are relined, you are likely to feel vibrations or pulsations transmitted through the brake pedal as the brake shoes wander in the space between the brake shoes and the drum.

Second, you are bound to hear squealing or squeaking noises whenever you press the brake pedal in a bid to stop the vehicle. Third, when your brake drum is relined, it is usual for the parking brake not to be able to prevent the vehicle from rolling off.

Other things that can happen when your brake drum is relined include a compromise in the braking effectiveness of your vehicle.

Furthermore, this can also increase your braking distance with possible dire consequences to both you and other road users alike. (Read Also: Are Scored Brake Discs Dangerous?)

Also, a relined brake drum can easily lead to the premature wearing of other important brake components as well.

How do you know if your brake drums are relined?

It is easy to know whether your brake drum is relined or not. All the same, one of the first things you are bound to observe is a general reduction in the effectiveness and performance of your brakes.

Another development you are likely to experience is the vibration or pulsation you will feel transmitted to the pedal whenever you want to brake the vehicle.

This vibration is due to the movement of the brake shoes in the space between the drum and the shoe brakes. Second, you are also bound to hear noises coming from around the brakes if your brake drum is relined.

Finally, your hand or parking brake is also likely to feel loose and unable to stop the car from rolling off after parking.

Whenever your brake drums are relined, it is also possible to know the status of the braking system through the brake indicator light, which is a feature most modern vehicles are equipped with and through which you can both monitor and control your brakes at ease.

All these are pointers to the fact that you may require replacement brake pads.

Can brake drums be relined – Conclusion

In the drum brake system, the brake shoes are forced by a hydraulic system against the internal surface of the drum.

This forceful contact will generate immense friction which will, in turn, give rise to extreme temperatures.

This temperature can lead to the distortion of the appearance of your brake drums as well as make them ineffective in braking.

Therefore, from time to time, it may be required for you to restore the inner surface of the drum. Progressively, as you continue to scrape the surface metal off the inside of the drum in a bid to smoothen it, its diameter increases as well.

Consequently, you may have to use bigger brake shoes until you have to replace the drum altogether. If you fail to do that, you are compromising the performance and effectiveness of your braking system, a situation that may have dire consequences for you and other road users.