Warning! The brake fluid used in the hydraulic clutch system is poisonous, so if it gets on your skin, immediately rinse the area with plenty of water. If the fluid gets into your eyes or inside your body, you should immediately consult a doctor. Some fluids are highly flammable and can catch fire even from contact with hot vehicle components. In addition, the fluid used in the hydraulic clutch system dissolves paint and plastic, so if the fluid gets on your vehicle's paintwork, rinse it with plenty of water. This fluid is also hygroscopic, i.e. it absorbs moisture from the air, and therefore it is not recommended to use the fluid if it has been stored in an open container for a long time.
Removal
Clutch master cylinder
A – clutch master cylinder; B – rubber hose coupling; C – connecting hose; D – nuts; E – clutch pedal servo spring; F – retaining ring; G – pedal bracket
Removal the servo spring socket from the pushrod, servo spring and washer
After raising the clutch pedal, remove the servo spring socket (1), servo spring (2) and washer (3) from the push rod.
1. The clutch master cylinder is mounted on the clutch and brake pedal bracket (see fig. Clutch master cylinder). Fluid is supplied to the clutch master cylinder through a flexible rubber hose from the brake fluid reservoir located in the engine compartment.
2. Remove the ground cable from the battery.
3. Remove the lower instrument panel trim on the driver's side.
4. Pull back the carpet under the pedals and cover the floor with rags to collect any fluid that has leaked from the hydraulic clutch system.
5. To reduce fluid loss, use a clean syringe to pump out as much fluid as possible from the corresponding chamber of the brake system reservoir so that the fluid level drops below the connection of the clutch master cylinder feed hose.
6. Place a suitable container under the clutch master cylinder.
7. Unscrew the fasteners and disconnect the hydraulic pipe from the clutch master cylinder. Plug the hole in the pipe and the clutch master cylinder to prevent contamination and reduce fluid loss.
8. Remove the two nuts securing the clutch master cylinder to the pedal bracket.
9. Raise the clutch pedal and remove the servo spring socket, servo spring and washer from the pushrod (see fig. Removing the servo spring socket from the pusher servo spring and washer).
10. Using a screwdriver blade, remove the retaining ring securing the clutch master cylinder pushrod to the pedal.
11. Disconnect the feed hose from the clutch master cylinder and remove the clutch master cylinder from the vehicle.
Disassembly and assembly
Attachment point of the pushrod dust cover to the clutch master cylinder housing
Removal the retaining ring from the clutch master cylinder
Removal the washer from the clutch master cylinder
Removal the push rod and piston from the clutch master cylinder housing
Removal the spring from the clutch master cylinder housing
(Material taken from a web resource: www.MercedesMan.ru)
Removal the plug and check valve from the end of the piston
1. Remove the pushrod dust boot from the clutch master cylinder housing (see Fig. Attachment location of the pushrod dust cover to the clutch master cylinder housing).
2. Using special pliers, remove the retaining ring and take out the washer (see Fig. Removing the Clutch Master Cylinder Snap Ring, Removing the Clutch Master Cylinder Washer).
3. Remove the push rod and piston together with the spring from the clutch master cylinder channel (see fig. Removing the pusher and piston from the clutch master cylinder housing, Removing the spring from the clutch master cylinder housing).
4. Remove the plug and check valve from the end of the piston (see fig. Removing the plug and check valve from the end of the piston).
5. Wash all clutch master cylinder parts in clean brake fluid and check their condition.
6. Check the clutch master cylinder bore and piston for wear and tear. If the clutch master cylinder bore is worn or has deep scratches, replace the clutch master cylinder assembly. If the clutch master cylinder components are in satisfactory condition, replace the rubber sealing rings.
7. Carefully remove the old O-ring from the piston. Dip the new O-ring in clean brake fluid and carefully install it on the piston so that the working lips of the new O-ring are on the spring side of the piston.
8. Lubricate the clutch master cylinder bore and piston with clean brake fluid and insert the spring into the cylinder.
9. Install the check valve and plug onto the piston and carefully insert the piston into the clutch master cylinder bore.
10. Press the push rod slightly into the clutch master cylinder, install the washer and snap ring into the groove of the clutch master cylinder bore.
11. Install the tappet dust boot in place and secure it to the clutch master cylinder housing.
Installation
1. Installation is carried out in the reverse order of removal, taking into account the following points.
2. Install the washer, servo spring, servo spring socket onto the pushrod, insert the pushrod into the pedal bracket guide while pressing the clutch pedal.
3. Check that the clutch master cylinder push rod eye is facing the clutch pedal with the flange facing the clutch pedal.
4. Do not install the driver's side lower instrument panel trim until the pushrod adjustment has been completed.
5. Fill the hydraulic clutch system with fluid and bleed the air from it.
6. Check the tappet adjustment.