Anti-Lock Brake Safety Precautions

WARNING: Failure to depressurize ABS could lead to physical injury.

NEVER open a bleeder valve or loosen a hydraulic line while ABS is pressurized.
NEVER disconnect or reconnect any electrical connectors while ignition is on. Damage to ABS control unit may result.
DO NOT attempt to bleed hydraulic system without first referring to the appropriate ANTI-LOCK BRAKE SYSTEM article in the BRAKES section.
Only use specially designed brake hoses/lines on ABS equipped vehicles.
DO NOT tap on speed sensor components (sensor, sensor rings). Sensor rings must be pressed into hubs, NOT hammered into hubs. Striking these components can cause demagnetization or a loss of polarization, affecting the accuracy of the speed signal returning to the ABS control unit.
DO NOT mix tire sizes. Increasing the width, as long as tires remain close to the original diameter, is acceptable. Rolling diameter must be identical for all 4 tires. Some manufacturers recommend tires of the same brand, style and type. Failure to follow this precaution may cause inaccurate wheel speed readings.
DO NOT contaminate speed sensor components with grease. Only use recommended coating, when system calls for an anti-corrosion coating.
When speed sensor components have been removed, ALWAYS check sensor-to-ring air gaps when applicable. These specifications can be found in each appropriate article.
ONLY use recommended brake fluids. DO NOT use silicone brake fluids in an ABS equipped vehicle.
When installing transmission devices (CB's, telephones, etc.) on ABS equipped vehicles, DO NOT locate the antenna near the ABS control unit (or any control unit).
Disconnect all on-board computers, when using electric welding equipment.
DO NOT expose the ABS control unit to prolonged periods of high heat (185 °F/85°C for 2 hours is generally considered a maximum limit).