What this test is for
Capture the safest useful operating pattern and location evidence so braking diagnosis does not begin with an unsupported assumption about a rotor or another part.
Use the procedure to narrow a cause group. The result must be interpreted against the exact vehicle, equipment, and conditions.
- 01PurposeCapture the safest useful operating pattern and location evidence so braking diagnosis does not begin with an unsupported assumption about a rotor or another part.
- 02PrepareSafe observation conditions / Inspection light
- 03MeasureCheck the stop-driving gate / Compare the trigger only when safe
- 04InterpretBraking safety takes priority; an unsafe vehicle should not be driven to reproduce a vibration.
- 05ContinueWheel/tire condition inspection / Brake-system inspection
Preserve the operating conditions, equipment setup, and result before moving to the next branch.
Tools and preparation
- Safe observation conditions
- Inspection light
- Accurate tire-pressure gauge
- Approved lifting and support equipment
- Exact brake service information
Procedure and interpretation
Check the stop-driving gate
Record warning lamps, pedal feel, pull, smoke, leakage, heat, wheel security, and handling from a safe position before moving the vehicle.
No active safety condition requires stopping the test and arranging qualified inspection.
Braking safety takes priority; an unsafe vehicle should not be driven to reproduce a vibration.
Compare the trigger only when safe
Under normal, legal, low-risk conditions, note whether the same road-speed range is smooth with the brakes released and changes with gentle brake application. Do not perform repeated hard stops or hands-off steering.
The complaint can be classified as brake-applied, road-speed, mixed, or not safely comparable.
The trigger chooses the next system path; it does not identify a failed rotor, pad, tire, hub, or suspension component.
Record where the feedback is felt
Note pedal pulsation, steering-wheel movement, seat/body vibration, noise, pull, speed, brake effort, road surface, and recent wheel or brake work.
Location and operating conditions are preserved as evidence rather than treated as a parts diagnosis.
Feedback can travel through the vehicle, so the strongest location is a clue and not proof of the source.
Inspect and measure the complete wheel-end
With approved support and the exact vehicle procedure, inspect tires, wheels, mounting, hubs, friction material, hardware, calipers, hoses, and suspension; measure only with the specified method and limits.
The next measurement or repair addresses a documented condition across both sides where applicable.
A measurement outside a vehicle-specific limit supports the relevant branch, but a universal internet threshold is not a safe substitute for service information.
Record this test result
Save a bounded result and note to the selected vehicle. This is a personal record, not a verified diagnosis.
Choose a vehicle in My Garage or the vehicle selector first. IAR will not attach a test result to an unknown vehicle.
What to test next
Safety boundary
Braking and road-test safety
Do not create a road test if braking is reduced, the pedal feels unsafe, the vehicle pulls strongly, a red warning is on, there is smoke, leakage, severe heat, wheel looseness, or unstable handling. Use qualified inspection or transport instead.