Repair Pontiac Mid-size 1974-1983 Repair Guide

Brake Master Cylinder



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Fig. Fig. 1 A. Minimum level mark To check the brake fluid level on some later model vehicles, remove the master cylinder lid ...

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Fig. Fig. 2 ... then check the level and add fresh DOT 3 brake fluid, if necessary

The brake master cylinder is located under the hood, in the left rear section of the engine compartment. It is divided into two sections (reservoirs) and the fluid must be kept within 1 / 4 in. of the top edge of both reservoirs. The level should be checked at least every 7,500 miles.

Any sudden decrease in the level of fluid indicates a possible leak in the system and should be checked out immediately.

To check the fluid level, simply pry off the retaining bar (if necessary) and then lift off the top cover of the master cylinder. When making additions of brake fluid, use only fresh, uncontaminated brake fluid which meets or exceeds DOT 3 standards (as stated on the container). Be careful not to spill any brake fluid on painted surfaces, as it eats paint. Do not allow the brake fluid container or the master cylinder reservoir to remain open any longer than necessary; brake fluid absorbs moisture from the air, reducing its effectiveness and causing corrosion in the lines.

The reservoir cover on some later models (1978-83) may be without a retaining bail. If so, simply pry the cover off with your fingers.