Mercedes Coupes/Sedans/Wagons 1974-1984 Repair Guide

Brake Master Cylinder



See Figures 1 and 2

Click image to see an enlarged view

Fig. Fig. 1: To add fluid to the brake master cylinder, unscrew the cap ...

Click image to see an enlarged view

Fig. Fig. 2: ... then add fluid until the level marked on the side of the reservoir is reached. Replace the cap

The brake master cylinder is attached to the brake booster which is located on the firewall (driver's side). To check the fluid level, proceed as follows.

  1. Clean the area around the cap since even minute particles of dirt can cause a malfunction of the system.
  3. Remove the top from the reservoir and check to see that the fluid is up to the marks stamped in the reservoir.
  5. Add fluid, if necessary, to bring the level up to the marks.

Use only a high quality brake fluid. Mercedes-Benz recommends ATE Blue Original brake fluid. In countries where this is difficult to obtain, use only fluid which meets or exceeds SAE J 1703B standards. This will be marked on the container.

Do not allow brake fluid to contact the vehicle's paint because brake fluid acts as a solvent.

  1. Replace the reservoir cap, making sure that the ventilation bore in the top is not blocked.