Clutch Master Cylinder: Service and Repair
Removing and installing master cylinder
Preliminary work
Information
The clutch master cylinder is installed under the brake booster, accessible from the plenum panel in the engine compartment.
1. Disconnect the battery.
2. Open bonnet and position it with the bonnet stay 9704.
3. Remove engine design cover.
4. Remove cowl panel cover.
5. Remove left plenum panel partition.
6. Partly remove fuse carrier, including six connectors, on the left in the plenum panel and lay to one side -arrow-.
General warning notes
Warning notes
Caution
Increased risk of accidents when working with brake fluid.
^ Possible danger of damage or injury.
^ Brake fluid on electrical contacts (even thinned brake fluid) leads to corrosion and may cause faults in the system.
-> Wear protective goggles and gloves.
-> IMMEDIATELY remove any escaped brake fluid. CAREFULLY rinse again with water and dry if necessary. Look out for fuse carrier!
Removing
Overview of pedals
Overview of pedals excluding stop light switch
-1- - Seal
-2- - Hexagon nut
-3- - Mounting saddle
-4- - Pin
-5- - Hexagon nut
-6- - Hexagon-head bolt
-7- - Seal
-8- - Fixing clip/screw
-9- - Master cylinder
-10- - Mounting
-11- - Bolt
-12- - Clutch pedal
-13- - Cap
-14- - Lock (mechanical)
-15- - Clutch power spring
-16- - Bearing shell
-17- - Rubber stop
-18- - Lock (mechanical)
-19- - Pin
-20- - Lock (mechanical)
-21- - Mounting saddle for clutch pedal
-22- - Switch (clutch pedal switch)
-23- - Switch (interlock)
Installation position of clutch master cylinder
Clutch master cylinder
-A- - Pressure line connection to clutch slave cylinder
-B- - Supply
-C- - Dust boot
-D- - Pushrod
1. Remove brake fluid by suction below MIN mark in reservoir.
Information
Brake fluid is hygroscopic! Seal all lines immediately with suitable plugs.
Brake fluid will flow from the lines. Protect body in the area under the clutch master cylinder (e.g. with a cleaning cloth).
2. Loosen pressure line from clutch master cylinder to slave cylinder -A-. To do this, remove safety clip to the stop using a screwdriver -direction of arrow-.
Removing safety clip for pressure line connection from clutch master cylinder
3. Open safety clip. The pressure line can now be pulled off -arrow-.
Opening safety clip for pressure line connection of clutch master cylinder
4. Remove lines on brake fluid reservoir and clutch master cylinder -B- (pull strongly!).
5. Remove clutch pedal. To do this, detach pushrod of master cylinder from pedal. Insert pliers T10005 in the cut-outs on clutch pedal. Remove clutch pedal -12-.
Disengaging clutch pedal
6. Remove fixing clips on clutch master cylinder. Carefully remove clutch master cylinder with a cleaning cloth (soiling of passenger compartment with brake fluid!).
Installing
Information
Use a new line from the brake fluid reservoir to the clutch slave cylinder.
If the switches -22 - 23- have been removed from the mounting saddle of the clutch pedal -21- they must be replaced and their operation checked.
Replace all seals and sealing rings.
^ Remove plugs from the lines.
Overview of pedals
Overview of pedals excluding stop light switch
1 - Seal
2 - Hexagon nut
3 - Mounting saddle
4 - Pin
5 - Hexagon nut
6 - Hexagon-head bolt
7 - Seal
8 - Fixing clip/screw
9 - Master cylinder
10 - Mounting
11 - Bolt
12 - Clutch pedal
13 - Cap
14 - Lock (mechanical)
15 - Clutch power spring
16 - Bearing shell
17 - Rubber stop
18 - Lock (mechanical)
19 - Pin
20 - Lock (mechanical)
21 - Mounting saddle for clutch pedal
22 - Switch (clutch pedal switch)
23 - Switch (interlock)
1. Fit master cylinder with fixing clip.
2. Fit clutch pedal.
3. Fit pressure line to clutch master cylinder. Engage safety clip -direction of arrow-.
Engaging safety clip for pressure line connection from clutch master cylinder
4. Connect line between brake fluid reservoir and clutch master cylinder (top and bottom).
5. Fill brake fluid reservoir with brake fluid. The brake fluid level must not exceed the MAX mark.
Subsequent work
1. Fit fuse box and clip in the six connectors. -arrow-
2. Fit left plenum panel partition, ensuring correct seating of gaskets and correct routing of wiring harness.
3. Fit cowl panel cover.
4. Install engine design cover.
5. Bleed the clutch.
6. Connect the battery.
Information
If clutch switches 22-23 on the mounting saddle for clutch pedal 21 have been removed, they must be replaced. Afterwards check operation of new clutch switches.
Check operation of both clutch switches -22-23- (see below: first switch (clutch pedal switch), second switch (interlock).
Overview of pedals excluding stop light switch
1 - Seal
2 - Hexagon nut
3 - Mounting saddle
4 - Pin
5 - Hexagon nut
6 - Hexagon-head bolt
7 - Seal
8 - Fixing clip/screw
9 - Master cylinder
10 - Mounting
11 - Bolt
12 - Clutch pedal
13 - Cap
14 - Lock (mechanical)
15 - Clutch power spring
16 - Bearing shell
17 - Rubber stop
18 - Lock (mechanical)
19 - Pin
20 - Lock (mechanical)
21 - Mounting saddle for clutch pedal
22 - Switch (clutch pedal switch)
23 - Switch (interlock)
1. First switch (clutch pedal switch) -22-
Connect System Tester and select >> PSM << system. In the menu >> Input signals/clutch switches << read out the switch states.
Depress clutch pedal (rest position) up to 11 mm from end-position 1 -A-
From end-position 1 of the clutch pedal (pedal not depressed!) to a pedal travel of 11 mm -A- the switch (clutch pedal switch) must be at >> Not actuated << in the System Tester. Measured using a steel rule at the tread plate of the clutch pedal - second worker required.
Depress clutch pedal over (!) 11 mm pedal travel:
^ Now the switch (clutch switch) must switch to >> Actuated <<.
If the switch (clutch pedal switch) does not operate, the installation position must be checked. If that does not succeed, then follow the troubleshooting procedure for PSM Fault Code 650.
2. Second switch (interlock) -23-
Connect System Tester and select >> Kessy << system. In the menu >> Input signals/clutch switches (interlock) << read out the switch states.
Clutch pedal end-position 2 (fully depressed) minus 20 mm depression -B-
From end-position 2 of the clutch pedal (pedal fully depressed!) minus 20 mm -B- the switch (interlock) must be at >> Actuated << in the System Tester. Measured using a steel rule at the tread plate of the clutch pedal - second worker required.
Depress clutch pedal up to 20 mm before (!) end-position2:
^ Up to that point the switch (interlock) must be at >> Not actuated << in the System Tester.
If the switch (interlock) does not switch over, the installation position must be checked. If that does not succeed, then follow the troubleshooting procedure for Kessy Fault Code 650.