Analyzing the complex braking behavior of tractor-trailer-trailer combinations under dynamic loads.
An interlink combination consists of a truck-tractor, a lead trailer (A-frame), and a rear trailer (B-frame). Unlike a single rigid truck or a standard semi-trailer, an interlink has multiple articulate couplings, up to 9 axles, and 3 distinct pneumatic relay loops.
When the operator applies the foot pedal, air pressure must travel over 15 meters to reach the brake chambers on the rear B-frame trailer. If the pneumatic loop is not balanced, the truck-tractor brakes will engage first. This causes the trailers to push the tractor forward, raising the risk of jackknifing.
Brake IQ's interlink testing procedures do not rely on basic deceleration calculations. We analyze individual axle behaviors using external high-frequency sensors, pressure logs, and time delay metrics.
A response delay exceeding 250ms on the rear trailer is a severe safety hazard. It suggests valve restrictions, partial blockages, or worn suzie couplers. Brake IQ calculates this timing delay under dynamic stopping cycles.
If the left side chambers build pressure faster or higher than the right side chambers on the same axle, the vehicle will pull to one side under heavy braking. We verify left-right balance across all 9 axles to identify sticky actuators or lining issues.
Calculates air travel time from the tractor cab to the furthest trailer chamber.
Compares peak delivery pressures across individual axles.
Monitors wheel slip ratios to isolate mechanical lining grab or cylinder binding.
Speak directly to a brake analytics specialist to review our test parameters.
Speak to a SpecialistEvery Brake IQ inspection follows a structured field process to ensure repeatable and accurate telemetry capture.
We connect high-frequency external wheel speed sensors to trailer axles and plug pressure transducers into the tractor and trailer pneumatic test points.
The vehicle performs controlled dynamic stops on a level surface under full GCM load while our telemetry units capture deceleration curves and wheel slip ratios.
We connect to the vehicle's J1939 CAN link to capture EBS controller parameters and active diagnostic fault codes, syncing all findings directly to the fleet console.