How is the braking system optimized for North American tractor trailer combinations?

One size does not fit all when it comes to brakes. Until now, the assumption has been that a standard European configuration transfers seamlessly to the North American market.  

As we researched the migration of air disc brakes from Europe to North America, we discovered that not much analysis had been done to understand how a European brake design functions in North America or how the differences in NAFTA tractor-trailer combinations could dictate a distinct air disc brake design for this market.  

For instance, differences in wheel base dimensions on vehicles in Europe versus North America translates to contrasts in workload distribution on typical NAFTA tractor trailer combinations compared to European vehicles. Other factors including regulations, certifications and maintenance practices contribute to the unique performance characteristics required for each market.  

The MAXX22T brake system is tuned to match the performance needs of a typical North American trailer and is approved for brake performance in 20,000 pound applications or up to 23,000 pound applications with appropriate tire SLR. See L809 for Brake Certifications.

Why partner with WABCO?

The Hendrickson MAXX22T features WABCO’s innovative brake caliper design. This field proven single piston design is lighter than other systems and consists of fewer moving components for increased robustness and simplified maintenance.

What is the bi-directional adjuster mechanism?

WABCO’s unique bi-directional adjuster mechanism allows the system to adjust the brake pad running clearance to a nominal value from both directions to minimize the risk of hot-running brakes.

Why is a single piston design better than a double piston for even wear?

Double piston designs must have the pistons timed to operate together to ensure even wear. Current double piston designs use a chain or gear between the two pistons, if the link between the two pistons breaks or is damaged the pistons will not move together which will result in uneven wear. A single piston design, like in MAXX22T utilizes a larger piston and spreader plate which eliminates timing issues and ensures even wear.

What is the weight savings compared to a drum brake application?

Hendrickson’s MAXX22T system saves one hundred pounds per tandem trailer over a similar drum brake configuration.

What is the acquisition cost of the system?

Many factors may affect pricing, so it is difficult to generalize the initial acquisition cost of the MAXX22T system. Fleets who are interesting in specifying our system should work directly with the trailer OEM for the most accurate price quotation.

What is the warranty?

The MAXX22T air disc brake system boasts a warranty of 5-years parts, 1-year labor.

MAXX22T is also available with any of Hendrickson’s Ready-To-Roll wheel-end packages and value-added options like TIREMAAX tire inflation systems. The warranty period for wheel end and tire inflation components corresponds to the specific Hendrickson Extended Life package that is chosen, either 3, 5 or 7 years.

Hendrickson assumes all warranty coverage for the brakes, the suspension and the wheel end components for hubcap-to-hubcap coverage and the convenience of a single source supplier.

For more information refer to L583 – Comprehensive Warranty Statement or contact your sales representative.

Where can customers get parts in the field?

MAXX22T parts are available through Hendrickson aftermarket and in most PDC channels. If a specific aftermarket channel needs set up, contact a Hendrickson sales representative and they can assist.

How do you check lining wear?

The lining wear indicator is located on the caliper casting and physically measure pad thickness. It is important to look at both pads, not just the overall wear. Some competitive products have a visual wear indicator which indicates overall wear, however it is not uncommon for one pad to be more worn than the other and this is not evident unless the pad thickness is measured.

Are special tools required for maintenance?

A tool kit is available from Hendrickson but an 8mm offset box end wrench could also be used.

What are the maintenance costs compared to drum brakes?

Maintenance costs can vary depending on factors such as trailer application, typical operation cycles, payload, driver habits and maintenance schedules. Anecdotally, we have heard that driver habits can play a major role in ascertaining potential maintenance costs. As air disc brakes become more popular on trailers in North America, it will be important to properly educate drivers about the differences in braking characteristics and maintenance practices between drum and air disc.

Is the MAXX22T serviceable?

Yes, the guide pins, pistons, boots and pads can all be replaced. Reference L1063 – Air Disc Brake Parts List for part numbers.

Are there any out-of-adjustment concerns in regards to air disc brakes?

While there are currently no inspection criteria requirements for adjustment on air disc brake systems in North America, following a systematic and routine maintenance schedule is important for ensuring maximum performance from the MAXX22T system. For instance, we recommend regular brake pad inspections to ensure even pad wear and routine rotor checks to validate that the rotor is free from cracks or other potential damage.

Can customers get MAXX22T on competitor suspensions?

MAXX22T is available exclusively on Hendrickson’s integrated suspension systems including INTRAAX® integrated axle/beam/brake systems and VANTRAAX® air slider systems.