ABC hydraulic struts — front

How you know it is this

• A 'Visit Workshop' or ABC warning, often with the car settling to one side
• Red hydraulic fluid on the driveway or down the inside of the wheel
• The car sinking overnight and slowly pumping itself up on start
• A harsh, uncontrolled ride

Worth knowing before you buy

• ABC IS NOT AIR SUSPENSION and shares nothing with it. Struts, pumps, accumulators and lines are all ABC-specific. Fitted to S-Class, CL and SL, not across the range.
• The system runs at very high pressure. It is not a job to open up without the correct procedure.
• Fluid is specific to ABC and the system is sensitive to contamination — a failed component usually means flushing as well.
• Expensive throughout. On an older car it is worth pricing an ABC repair against the value of the car before committing.

Rest of the active body control (abc)

• ABC hydraulic struts — rear
• ABC tandem hydraulic pump
• ABC pressure accumulators (spheres)
• ABC pulsation damper
• ABC valve blocks
• ABC hydraulic fluid reservoir and filter
• ABC hydraulic lines and hoses
• ABC control module
• Body acceleration and level sensors
• ABC hydraulic fluid