Clutch Fluid: Service and Repair
Bleeding the clutch system - as of model year 2009
Information
Information on clutch hydraulic system - as of model year 2009
A return line -1-, from the clutch slave cylinder -2- to the reservoir -4-, is used as of model year 2009. This return line -1- is fitted on the bleeder valve -3- of the clutch slave cylinder -2-.
The return line -1- must also be filled/bled. The bleeding tool 9781 is required for this.
If the return line is not bled, this can result in a change in the brake fluid level while the vehicle is driving!
Overview of clutch return line
Important notes on bleeding
The clutch hydraulics must always be filled or bled using a bleeding device. Furthermore, the bleeder valve must be opened by 1 to 2 turns and the overpressure on the bleeding device must be approx. 1.3 bar (19 psi).
Once the filling or bleeding process has started, the clutch pedal must be moved (extremely slowly) into the "Pedal fully depressed" position.
As there is no system pressure, servo kinematic effects will cause the clutch pedal to move forward abruptly. In order to avoid damage, the pedal must be guided manually.
In general, a minimum filling time of 90 seconds must be observed. Once this filling period has elapsed, check that no more bubbles appear at the bleeder valve (use a collecting bottle with transparent hose). Only then should you close the bleeder valve.
Filling/bleeding the clutch system
Filling/bleeding
Information
In general, a minimum filling time of 90 seconds must be observed.
Use only new Super DOT 4 class brake fluid. This brake fluid is available under the following part numbers:
Container quantity 1 liter = 000.043.203.66
Container quantity 30 liters = 000.043.203.67
1. Remove cover over the brake fluid reservoir. Fill reservoir to its top edge with new brake fluid. Connect the bleeding device to the reservoir.
Do not switch on the bleeding device yet!
2. Remove cover for rear underbody (to gain access to the bleeder valve and return line).
3. Remove return line -1- at the clutch slave cylinder -2- and close it off immediately using bleeding tool 9781 -5-.
3.1. Release return line -1- at the clutch slave cylinder -2- (-arrows-) and pull it off the bleeder valve -3- at the same time.
Releasing and pulling off return line
3.2. Then, insert bleeding tool 9781 -5-, set to Closed position (knurled screw -6- turned clockwise as far as it will go), into the return line -1-.
Closing off return line
Brake fluid will emerge for a short time until the return line is closed (soak up brake fluid using a lint-free cloth).
4. Switch on the bleeding device and set an overpressure of approx. 1.3 bar.
5. Connect a collecting bottle -7- with a transparent hose to the bleeder valve -3-.
Connecting collecting bottle to the bleeder valve
Open the bleeder valve -3- on the clutch slave cylinder -2- by 1 to 2 turns.
6. Move pedal extremely slowly to the "Pedal fully depressed" position. When doing so, guide the pedal by hand so that it does not move forward abruptly.
7. Allow the brake fluid to rinse through for 30 seconds.
8. Afterwards, activate complete pedal travel with your hand very slowly for a further 60 seconds. After about 10 to 15 pedal strokes, leave the pedal in its normal position. Once this filling period has elapsed, check that no more bubbles appear at the bleeder valve (use a collecting bottle with a transparent hose). Then close the bleeder valve (tightening torque = 5 + 1 Nm (3.5 + 0.5 ft. lbs.).
9. Fill/bleed the return line -1- using the bleeding tool 9781 -5-.
Collecting bottle hose on return line
9.1. Connect collecting bottle (with a transparent hose) -7- to the return line -1- or to the fitted bleeding tool 9781 -5-.
Open bleeder valve (knurled screw) -6- on special tool -5-. Let brake fluid flow through until no more air bubbles appear. Then close the knurled screw -6-.
9.2. After bleeding the return line, switch off the bleeding device.
10. With the bleeding device switched off, fit the clutch return line -1- on the bleeder valve -3- (of the clutch slave cylinder -2-).
10.1. Remove special tool 9781 -5- from the return line -1-.
Return line with special tool 9781
10.2. Then, fit the return line -1- on the bleeder valve -3- of the clutch slave cylinder -2- immediately (connect until it locks).
Fitting return line
Brake fluid will emerge for a short time (soak up brake fluid using a lint-free cloth).
The emergence of brake fluid is normal and does not affect the system function.
Check that the return line is seated correctly!
11. Close off the bleeding device, which is now switched off. Check the brake fluid level. It should not be above the MAX marking on the brake fluid reservoir.
Brake fluid level
12. Activate the clutch pedal slowly, five times.
13. Fit the cover over the brake fluid reservoir.
14. Fit cover for rear underbody.