Warning! The brake fluid used in the hydraulic clutch system is poisonous, so if it comes into contact with the skin, immediately wash the area with plenty of water. If the liquid gets into the eyes or inside the body, you should immediately consult a doctor. Some fluids tend to be highly flammable and can ignite even from contact with hot vehicle components. In addition, the fluid used in the hydraulic clutch system dissolves paint and plastic, so if fluid comes into contact with the car's paintwork, wash it with plenty of water. Also, this liquid is hygroscopic, i.e. it absorbs moisture from the air and, therefore, it is not recommended to use liquid stored for a long time in an open container.
Attention! To bleed the hydraulic clutch system, Mercedes-Benz recommends the use of special equipment that makes it possible to bleed the air under pressure.
Any hydraulic system operates normally and reliably when air is removed from the hydraulic fluid in the system.
When bleeding, add only clean fluid of the correct type. Never reuse fluid that has leaked from the hydraulic clutch system.
If fluids of different types are accidentally mixed in the hydraulic system, remove the fluid from the hydraulic system, flush the system with clean fluid of the correct type, and install new O-rings.
If fluid leaks continuously from the hydraulic system or air enters the hydraulic system, determine the cause and location of the leak and repair the damage.
Installing the tube (1) on the bleeder valve (2) clutch slave cylinder
1. Raise the front of the car and secure it on stands.
2. Remove the engine mudguard.
3. Check that the connection between the hydraulic tube and the clutch hose is securely tightened and the bleeder screw on the back of the clutch slave cylinder is screwed on. Remove the dust cap from the bleeder port and clean any traces of dirt near the port.
4. To remove air from the hydraulic system, it is necessary to use special equipment operating from external pressure (inflated spare wheel chamber). After connecting a sealed fluid chamber to the brake system reservoir, bleeding consists in draining the fluid through the bleeder valve on the clutch slave cylinder until the leaking fluid comes out free of air bubbles.
5. Using this method with a large fluid reservoir provides additional protection for the hydraulic clutch system from possible air ingress during bleeding.
6. Put a transparent hose on the bleeder fitting, lower the other end into a glass vessel partially filled with brake fluid (see picture).
7. Connect a pressurized air bleeder to the brake reservoir according to the instructions.
8. Unscrew the bleed screw half a turn and allow the liquid to drain into the glass container until it comes out free of air bubbles.
9. After removing air from the hydraulic clutch system, screw in the bleeder screw, remove the hose from it and remove the tool from the reservoir.
10. Clean the bleeder valve of brake fluid and install the dust cap on it.
11. Check the brake fluid level in the reservoir and add brake fluid if necessary.
12. Check the clutch pedal for smooth travel. If the clutch pedal jerks when pressed, there is air in the clutch hydraulic system. If, after re-bleeding the clutch pedal again, it moves unevenly, then the sealing rings of the clutch master or slave cylinder are worn out.
13. Lower the car.