GM Caprice 1990-1993 Repair Guide

Master Cylinder



When adding or replacing the brake fluid, always use a top quality fluid, such as Delco Supreme II or DOT-3. DO NOT allow the brake fluid container or master cylinder reservoir to remain open for long periods of time; brake fluid absorbs moisture from the air, reducing its effectiveness and causing corrosion in the lines.


See Figure 1

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Fig. Fig. 1: Checking master cylinder fluid level

The master cylinder is located in the left rear section of the engine compartment. The brake master cylinder consists of an aluminum body and a translucent nylon reservoir with minimum fill indicators. The fluid level of the reservoirs should be kept near the top of the observation windows.

Any sudden decrease in the fluid level indicates a possible leak in the system and should be checked out immediately. Do not allow brake fluid to spill on the vehicle's finish; it will remove the paint. In case of a spill, flush the area with water and mild soap.

Although it is not mandatory, it is recommend that you periodically flush the brake lines with new brake fluid, this will help stop the corrosion buildup in the brake system. However, if the vehicle is equipped with an Anti-Lock Brake System (ABS), it is essential that the system be flushed once a year. Use the brake bleeding method, described in Brakes , to accomplish this procedure.