Brake Testing

The Navistar Proving Grounds provides a complete brake test facility to support any customer’s vehicle brake testing needs: Garage facilities for both light vehicles (passenger cars/light trucks) and heavy vehicles (RV, military, tractor-trailer, buses and construction equipment). Facilities include, among others, hoists, scales, alignment equipment, ballast and machine shop.

The Navistar Proving Grounds provides complete instrumentation and computerized data acquisition of the following brake performance parameters: stopping distance, vehicle velocity, pedal force, pedal travel, hydraulic or air line pressure, brake/rotor temperature, booster vacuum, brake torque, individual wheel speeds, parking brake control/cable force, vehicle deceleration and component acceleration.

Vehicle Sensitivity To Disc Thickness Variation

 

 

Navistar has trained personnel skilled in the various areas required to support vehicle brake system testing:

  • Technicians experienced with vehicle mechanical buildup (pretest) and instrumentation installation
  • Performance drivers experienced with both light and heavy vehicles and with the various FMVSS, TSD, SAE, ECE and other industry procedures
  • Engineers experienced with customer program coordination, test supervision, data analysis, problem solving and test report preparation

 

 

Vehicle brake system testing and development capabilities:

  • FMVSS 105 (hydraulic and electric brakes for vehicles over 7,716 lbs. GVW)
  • FMVSS 135 (hydraulic and electric brakes for vehicles under 7,716 lbs. GVW)
  • FMVSS 121 (air brake equipped vehicles)
  • TSD 105, 135 and 121 (Canadian equivalent of FMVSS 105, 135 and 121)
  • SAE J843 (passenger car/light truck hydraulic brake performance)
  • ECE Reg 13 (European brake systems)
  • Brake system balance evaluation (vehicle stability under braking)
  • Brake fade evaluation (vehicle braking effectiveness at high temperatures)
  • Magazine brake tests (AMS, Consumer Reports)
  • Brake system effectiveness
  • Brake system structural test (spike apply test)
  • Brake system noise evaluation
  • Simulated L.A. city traffic lining wear/brake noise test
  • ABS evaluations on various surface coefficients
  • Hill-hold testing (parking-brake evaluation) on 15%, 20%, 30% and 60% grades
  • Dynamic park brake stops
  • Pedal feel evaluation
  • Roughness evaluation
  • Ability to support complete brake system DVP&R programs
  • Brake testing road surfaces, including high-coefficient asphalt and various low-coefficient (wetted) surfaces for ABS testing and development; off-road (gravel) surfaces also are available for ABS evaluation
  • Brake rotor machining with specific run-out and disc thickness characteristics, including first and second order contributions
City Traffic

 

Test Overview
  • On- and off-grounds routes are available to evaluate the brake system for noise, friction components for wear and rim appearance for brake dust issues
  • The on-grounds route replicates city traffic driving patterns with occasional temperature profiles simulating grade descents as well as steady state driving performed to duplicate freeway-cool-down-type driving
  • Off-grounds route features a driving pattern through actual city traffic (South Bend, Indiana)
Key Measured Parameters
  • Acceleration at the brake calipers and/or anchors that is used to correlate to the sound pressure level measured in the cab of the vehicle. Accelerations and microphone frequency data are analyzed in increments of 0.25 second to determine if a noise event occurred.
  • Brake temperatures, pressures, speed and deceleration are recorded.

Click to view a sample city traffic shift NVH summary
PDF, 295 KB

Click to view a sample city traffic noise NVH detail
PDF, 255 KB

Suburban Traffic

 

Test Overview
  • 20,000-mile test to duplicate Detroit suburban traffic route
  • Used to predict the propensity of brake system to generate disc thickness variation (DTV)
  • More consistent route than “Detroit” route because of repeatable traffic and non-congested traffic patterns

Key Measured Parameters

  • Disc thickness variation at various mileage intervals using proximity sensors
Related Services
  • Vehicle sensitivity to disc thickness variation test to quantify a vehicle’s sensitivity to the DTV growth in a controlled setting

Click here to view a sample suburban traffic NVH summary
PDF, 38 KB