Replacing your truck’s brake pads

Brake pads and disks are fundamental components of any disk brake system and it is paramount to maintain them in perfect efficiency to guarantee reliable operation of the truck during braking, along with naturally guaranteeing the safety of those onboard. For these reasons one must follow a few simple rules during maintenance of the truck’s brake pads and disks. When should you replace your truck’s brake pads? The answer is in this article.

Brake pads

Brake pads are one of the components of a disk brake. A pad is made up of a metallic base on which a layer of friction material is applied, the composition of which may vary. The layer of material will create friction with the brake disk the moment it is pressed against it. The quality of the material will determine efficiency, or braking force, and the lifespan of the pads themselves. Brake pads, regardless of their use, can be made of:

  • Polymer material: by now unused for the past 40 years, consisting of asbestos (chrysotile);
  • Organic or carbon-ceramic material:usually consisting of an organic resin (phenolic o cresylic) for bonding (from 30% to 40%) and a fibrous component for reinforcing purposes. The fibrous component consists of multiple types (glass fibers, carbon, metallic, ceramic, aramid). A filler component and a friction modifier (to improve friction property) are also used, such as copper, iron, aluminum and zinc. Flakable materials such as graphite or mica may replace powdered metals. As for metallic carbon material, it differentiates itself from organic material for the larger quantity of carbon-ceramic used as opposed to fillers;
  • Synthetic material: this material generally contains copper and is used to improve braking force and pad lifespan. Synthetic materials are typically used in sporting contexts and present metallic powders agglomerated and fixed to the support with a high-temperature, high-pressure treatment;
  • Semimetallic carbon-ceramic or semimetallic organic material:consists of a mix between carbon-ceramic (or organic) and synthetic materials.
  • To cover our bases, let us see what may be defects in “low cost” brake pads:
  • Lack of mechanical fixing of the friction material, with possibility of detachment of the latter from the support
  • Inappropriate use of tension springs , which can lead to premature wear and tear of braking components, vibrations and noise
  • Lengthened braking distance superiore
  • Rapid deterioration of the brake pads

    Overheatingof the brake pad after repeated braking can be very dangerousas it can cause fading (loss of braking efficiency) and subsequent lengthening of braking distances. Other pads may violate the specifics of brake caliper producers (for example Knorr-Bremse).
    Lack of chamfering and lack of material between base and friction material may too cause overheating, which can result in deterioration of the braking disk and cracks.

When should you replace your truck’s brake pads

Being components heavily subject to wear and tear, brake pads should be replaced regularly. Systems have been developed to make the right moment for replacement noticeable, described as follows :

  • Grooves in the friction material: a simple method in which, when the pad becomes worn down to the same level as the bottom of the groove (which then becomes invisible) the time has come for replacement. This solution allows for more leading edges and allows for greater braking capacity. It also plays a role in brake cleaning, as the groove (especially if specially-made for the purpose) allows for the swifter draining of water and other impurities. This system also reduces gases and dusts that may manifest as a result of braking and might reduce friction between the pads and the disk, subsequently causing imbalanced wear.
  • Acoustic signal: consisting of soft metals (to avoid damaging the disk), a small layer or pin is calibrated to the minimum thickness of the friction material used; when applied to the metal part of the disk, it produces a noticeable screech.
  • Electrical contact: affixed within the friction material or on the metallic support; when in contact with the braking disk it closes an electrical circuit, turning on a warning light on the dashboard.
What can not replacing braking pads lead to
  • Deformation of brake disks: rendering them unusable;
  • Crystallization of braking materials: on downward slopes, for example in mountain driving, while holding the brake down, the vehicle does not stop.
  • Disk scruffing: may compromise new pads and overall braking quality.