GM Metro/Sprint 1985-1993 Repair Guide

Master Cylinder


At least twice a year the brake master cylinder reservoir should be checked for the proper fluid level. A low fluid level can indicate worn disc brake pads. A large loss in fluid may indicate a problem or leak in the system. Have it serviced immediately.


Use only heavy-duty Delco Supreme 11 or DOT 3 brake fluid.


See Figure 1

Click image to see an enlarged view

Fig. Fig. 1: Brake master cylinder reservoir

The brake master cylinder reservoir is made of translucent plastic so that the fluid level may be checked without removing the cap. If the fluid level in the master cylinder reservoir falls below the MIN line molded on the side of the reservoir, add brake fluid to bring the level up to the MAX line.

Clean the top of the reservoir off before removing the cap to prevent dirt from entering the master cylinder. Pour the fluid slowly to prevent air bubbles from forming. Reinstall the cap immediately.

Brake fluid damages paint. It also absorbs moisture from the air; never leave a container or the master cylinder uncovered any longer than necessary. All parts in contact with the brake fluid (master cylinder, hoses, plunger assemblies and etc.) must be kept clean, since any contamination of the brake fluid will adversely affect braking performance.