Dynamic Ride Control (DRC), System Pressure Check
Dynamic Ride Control (DRC), System Pressure Check
Special tools, testers and auxiliary items required
• Charging device (V.A.S 6209/2)
• Hand vacuum pump (VAS 6213)
Bleed charging device (V.A.S 6209/2)
Use only approved oil for the bleeding procedure.
• Charging device (V.A.S 6209/2) must always be bled at initial use.
• If charging device (V.A.S 6209/2) still shows a residual pressure greater than 0.5 bar (e.g. from a previous reading), bleeding must not be done.
- To bleed pressure gauge - B - and line section - A -, install special tool as shown in illustration.
• Illustration shows bleeding process by extracting hydraulic oil with (VAS 6213)
- Bleed process must be performed until air bubbles are no longer visible in hose - C -.
- Disconnect hose - C - and - D - and perform system pressure check.
System pressure check is performed on front shock absorber of corresponding DRC line.
• To attach or detach charging device (V.A.S 6209/2) , system line to be checked must be locked at central valve to limit the quantity of oil leaked to a minimum and to prevent pressurized central valve from emptying.
- Remove the wheel.
- Loosen the nuts - arrow -, remove the clips - 1 - and plastic cover.
- Loosen lock nut - 1 - on line to be checked, screw in shut-off screw - 2 - until it is hand tight and lock nut - 1 - again.
- Remove the cap from the extract/fill valve and connect the (V.A.S 6209/2).
- Loosen lock nut - 1 - on line to be checked, unscrew shut-off screw - 2 - until it is hand tight and lock nut - 1 - again.
- Read system pressure at (V.A.S 6209/2).
• Pressure increase at (V.A.S 6209/2) occurs slowly and takes approximately 2 minutes. DRC system pressure can only be read when (V.A.S 6209/2) needle has finally come to a stop.
- Loosen lock nut - 1 - on line to be checked, screw in shut-off screw - 2 - until it is hand tight and lock nut - 1 - again.
- Disconnect (V.A.S 6209/2) and install dust cap.
- Loosen lock nut - 1 - on line to be checked, unscrew shut-off screw - 2 - until it is hand tight and lock nut - 1 - again.
• Small oil leak which results from connecting or disconnected (V.A.S 6209/2) at connection is not critical. Avoid repeating measurements because a small quantity of oil is removed from the system every time the (V.A.S 6209/2) is connected. Every connection results in a pressure decrease of approximately 0.3 bar from the previous reading. Multiple repeated measurements decrease system pressure below minimum pressure or failure.
- If the pressure is not OK, determine the cause and service the system.
- Install the plastic cover.
Tightening specifications:
- Nuts - arrow - 2 Nm
DRC System Pressure Values
Pressure values refer to reference temperature of 20 °C.
• 16 bar = Maximum pressure
• 15 bar - 16 bar = Central valve new or as good as new
• 12 bar - 15 bar = Normal range of operation, system OK
• < 12 bar = System leaking or not filled completely, air entering system, central valve has no pressure/is empty.