Portable Brake Dynamometer
On
August 9, 2002 the Federal Motor Carrier Safety Administration issued a final rule that allow motor carriers and federal, state and local enforcement officials to use roller brake testers to determine whether a truck or bus complies with brake performance standards in FMCSR 393. Analysis, Inc., by using this tool, can uncover some of the following problems:
- Defective automatic slacks (under & over – adjusted)
- Disconnected brakes
- Poor low-pressure balance between tractors and trailers (causing excessive wear and premature trailer or tractor wheel lockup)
- Very high crack pressures on steering axles (increases jackknife risk)
- Reversed bobtail proportioning systems (proportioning when trailer attached)
- Broken parking brake springs
- Crossed ABS wiring
- Pinched or blocked air lines
- Sticking or frozen relay valves & quick release valves
- Brakes adjusted “backwards” by mechanics
- Improperly ground shoes (low brake output)
- Leaking wheel seals
The Brake Dynamometer can be used to dynamically test ABS and Automatic Traction Control Systems. By having the wheels rolling and the brakes activating we can:
- Check sensor outputs
- Verify that sensor wiring is not crossed (left/right)
- Fire ABS and ATC solenoids to make sure they are functioning
- Verify that solenoid wiring is not crossed left/right and that the hold and dump functions are not reversed.