Brake Dust Shields
What are Brake Dust Shields?
Dust shields are found in all braking systems from light-duty vehicles to heavy-duty trucks and trailers using both drum and disc brakes. Dust shields are used to help preserve and protect the components of your truck or trailers brakes. When servicing your brakes they should be replaced if damaged or missing to keep protection in place. Brake dust shields not only protect the wheels from brake dust, but they also protect the brakes from debris and dirt that can impact the lifespan and function of the brakes. They can also protect the wheel seals by preventing the intrusion of items that may be able to cut or become entangled in the seal as the hub rotates.
With the open-air design of disc brakes, they will naturally shed debris and moisture using centrifugal force. The dust shield will primarily protect the wheels and surrounding components from brake dust. Due to the metals contained in brake pads, the dust can be corrosive and cause damage when exposed to moisture. Friction between the pads and the rotor can static charge the dust and make it more likely to stick to surrounding surfaces. Brake dust shields keep the dust on the outward portion of the wheel where it is more likely to be washed away.
How do Brake Dust Shields work?
Dust shields sit inboard of the brake assembly, and they are attached to the brake spider or clamped to the axle. On drum brakes, the dust shield closes off the interior of the drum that would normally be exposed. Without a dust shield, stones and other rubble can enter the drum and get trapped between the drum and shoes which can carve deep gouges in the drum and damage the shoes. Dust shields will also protect from water and salt spray during wet or wintry conditions that can accelerate corrosion and wash away lubrication on high wear components. The dust shields are not a hermetic seal and there will still be some intrusion of moisture, but with a dust shield installed it will be greatly reduced
How do I Identify Which Dust Shield I need?
Dust shields are application specific and fitment will depend on multiple factors.
- Brake Size – Brake size is used to determine the diameter that the dust shield will need to cover. A larger diameter drum will require a larger shield to cover it completely.
- Brake Type – The brake type will determine how dust shields are shaped around the various components of the brake system. Brake type may include the brake manufacturer and drum or air disc. Axle diameter will also come into play for dust shields that are attached to the axle housing instead of the brake spider.
- Diameters – The inner and outer diameter measurements of the dust shield will allow you to confirm that they will clear the axle tube and allow for complete coverage of the brake assembly.
Dust shields may seem insignificant, but they can protect the brake system and increase its lifespan. When performing a brake service, dust shields should be on the list of components that are checked and replaced as needed. If you have questions about dust shields or need help locating replacements, please reach out to us at TruckSpring.com or call us at 1-800-358-4751.