Checking control valve and spring cylinder for leaks — AUDI

Note:

Checking for leaks is best performed on a lifting platform with ramp or over a pit.

Checking control valve and right spring cylinder:

Remove dust cap from one of the bleed screws (=> Item
43-16
).
Attach bleed hose of pressure tester -V.A.G 1354- to bleed screw.
Open bleed screw, use suitable vessel to collect hydraulic fluid which emerges.
Tighten bleed screw on distribution piece.
Pull bleed hose off bleed screw on distribution piece and attach to bleed screw of pressure tester.
Unscrew pressure line from distribution piece (=>Item
43-12
).

Connect pressure tester -V.A.G 1354- to pressure line, 15 Nm.
Load luggage compartment with approx. 150 kg.
Start the engine and run at idling speed.
Observe reading on pressure gauge, switch off ignition at approx. 50 bar. Note gauge pressure.
Leave vehicle for roughly 3 hours.
Check reading on pressure gauge: Max. pressure drop 5 bar.
If pressure drop exceeds 5 bar, either control valve or spring cylinder is leaking and should be replaced.
Open joint on -Item.
43-14
).
If more than 0.2 cl of fluid escapes at this location, replace the right spring cylinder.
If no fluid escapes at this location, replace the control valve.

Carefully open -V.A.G 1354- pressure tester bleed screw, use suitable vessel to collect hydraulic fluid which emerges. The pressure gauge pointer drops slowly. Remove pressure tester -V.A.G 1354-.

Checking control valve and left spring cylinder:

This check is identical to right hand side except for the following steps.
Open joint on -Item.
43-15
).
Connect pressure tester -V.A.G 1354- to pressure line, 15 Nm.
If pressure drop exceeds 5 bar, either control valve or spring cylinder is leaking and should be replaced.
Open the joint on rear longitudinal member -Item
43-13
).
If more than 0.2 cl of fluid escapes at this location, replace the left spring cylinder.
If no fluid escapes at this location, replace the control valve.

Carefully open -V.A.G 1354- pressure tester bleed screw, use suitable vessel to collect hydraulic fluid which emerges. The pressure gauge pointer drops slowly. Remove pressure tester -V.A.G 1354-.