Air Suspension, Checking For Leaks

Special tools and workshop equipment required 

• Air Suspension Leak Tester:VAS 751 001 
  Fig 1: Air Suspension Leak Tester

  Courtesy of AUDI

TIP:

The Air Suspension Leak Tester:VAS 751 001  is used to check for leaks in the air spring dampers, the solenoid valve block, the pressure reservoirs, and the air lines.

-- Disconnect the air line that runs to the component that will be tested from the solenoid valve block. Refer to COMPONENT LOCATION OVERVIEW - AIR SUSPENSION .

-- Connect the adapter -1- to the solenoid valve block -2-.

Courtesy of AUDI

-- Connect the adapter -3- to the corresponding air line -4-.

-- Connect the connecting cable -5- on the tester to the adapter -1-.

-- Switch on the tester -1-.

Courtesy of AUDI

-- Open both shut-off valves -A- and -B- of the Air Suspension Leak Tester :VAS 751 001  .

-- Fill the air suspension system. Refer to AIR SUSPENSION SYSTEM, FILLING AND BLEEDING .

-- Initiate and lock the standard vehicle height. Refer to STANDARD VEHICLE HEIGHT, INITIATING AND LOCKING .

-- Check the pressure gauge to see if the pressure is decreasing.

-- If the pressure is decreasing, then close the shut-off valve in the direction of the solenoid valve block.

• If the pressure does not continue decreasing, then the cause is in the direction of the solenoid valve block.

-- If the pressure continues to decrease, then check the air line connection at the affected component, such as the left from suspension strut, for leaks.

-- Disconnect the air line directly at the affected component, such as the left front suspension strut.

• Follow the guidelines for clean working conditions. Refer to GUIDELINES FOR CLEAN WORKING CONDITIONS .
• Make sure that during the assembly work, no pressure points are created on the air suspension boot.
• If the air line is removed from a component, check if the cutting ring is seated on the air line.

-- Remove the air line -2- on the residual pressure valve -3-. The air escapes from this.

Courtesy of AUDI

-- Connect the tester -1- between the component to be checked and the air line.

Courtesy of AUDI

-- Open both shut-off valves -A- and -B- of the Air Suspension Leak Tester :VAS 751 001  .

-- Fill the air suspension system. Refer to AIR SUSPENSION SYSTEM, FILLING AND BLEEDING .

-- Check the pressure gauge to see if the pressure is decreasing.

-- If the pressure is decreasing, then close the shut-off valve in the direction of the solenoid valve block.

• If the pressure continues to decrease, then the component being tested is the cause.
• If the pressure does not continue decreasing, then the air line is the cause.