BMW E61 self-levelling compressor, dryer and hoses
Where does the E61's self-levelling compressor hose usually break?
The fabric hose usually breaks right at the compressor's nipple. The hose runs from above the right rear wheel to behind the inner wing. The inner diameter is 6 mm, and about 40–50 cm of the flexible part is needed.
What can replace the fabric hose?
A transparent urethane hose with a 6 mm inner diameter works as a replacement. Urethane hose can crumble in your hands, so check its condition before installing.
Does the compressor have a dryer and how do you open it?
The compressor has dryer granules. The dryer is fastened with two bolts, and the compressor has to be removed before opening it. A rusted centre bolt comes off with a long T30 Torx bit and a long 10 mm socket.
Where is the self-levelling relay and what does it control?
The green relay is at the bottom of the spare parts box, under the styrofoam plate. It only feeds the compressor and does not control the air bag valves, so replacing the relay alone may not fix the fault.