Raybestos® Update

Raybestos Adds New Air Disc Rotor Part Numbers to Specialty Line

MCHENRY, Ill., June 24, 2019 – With the recent addition of four new air disc rotor part numbers to its specialty rotor line, Raybestos® now offers increased coverage for air disc applications, and intends to release additional part numbers later this year. 

“We’re thrilled to continue expanding our air disc rotor offering to pair with our already strong air disc brake pad offering,” said Sam Rusenovich, director of sales – commercial vehicle and customer experience, Brake Parts Inc LLC. “Our air disc products are specifically designed to handle the demands of class 7 and 8 vehicles by providing better stopping power and unmatched durability. All of our air disc products meet or exceed original design and performance requirements.” 

Raybestos air disc rotors are designed to meet or exceed OE fit, form, function and SAE metallurgy. This discipline in design allows for better endurance under extreme temperatures and vehicle load. All rotors are 100 percent coated with Grey Fusion 4.0™ technology for corrosion resistance. Raybestos air disc rotors are qualified by the new SAE J3080 crack test procedure for air disc brakes, written specifically for these applications in 2018. Raybestos not only passed this rigorous test, but far exceeded its stringent requirements. 

Raybestos also has a complete offering of medium duty products developed for demanding work environments and created with fleets in mind. With outstanding performance and stopping power, even in extreme load and temperature conditions, Raybestos covers all fleet needs, from class 1 hydraulics through class 8 air disc. 

Raybestos® Training Update

Types of Drum Brake Systems

Drum brake systems are typically categorized as either a duo-servo or non-servo type setup. In this training video, we discuss the difference between these setups and how they operate. 

Duo-Servo Systems: 

Duo-servo brake systems are also known as primary/secondary drum brake systems. This is because there is a primary shoe and a secondary shoe. The primary shoe has less friction material than the secondary shoe. The primary shoe should be installed in the front, and the secondary shoe in the back. 

In duo-servo systems, the shoes link at the top at an anchoring pin and at the bottom at the self-adjuster. When you press the brake pedal on a duo-servo system, the hydraulic pressure from the wheel cylinder pushes the upper parts of the shoes outward. The primary shoe makes contact with the drum first, and the rotation of the drum tries to pull the shoe downward. 

This energy causes the primary shoe to push against the adjuster. The adjuster then forces the secondary shoe outward against the drum. The combination of this outward movement and the rotation of the drum causes the secondary shoe up against the anchoring pin. This cause the shoes to bind against the drum and stops it from rotating. Therefore, the secondary shoe provides the majority of braking power. 

Non-Servo Brake Systems:

The difference between duo-servo and non-servo systems is that the anchoring pin is on the bottom. This means that the application of one shoe has no effect on the other. In non-servo systems, there is a leading shoe and a trailing shoe. The leading shoe is the shoe that moves in the direction the drum is moving. Thus, the leading shoe changes depending on whether you are in forward or reverse.

In either case, the leading shoe provides the majority of the braking force. The rotation of the drum causes the leading shoe to apply with greater force than the trailing shoe.

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