GM Corvette 1984-1996 Repair Guide

Brake Master Cylinder



When adding or replacing the brake fluid, always use a top quality fluid, such as Delco Supreme II or equivalent DOT-3 fluid. DO NOT allow the 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.

Avoid spilling brake fluid on any of the vehicle's painted surfaces, wiring cables or electrical connections. Brake fluid will damage paint and electrical connections. If any fluid is spilled on the vehicle, flush with water to lessen damage.


See Figures 1, 2, 3, 4, 5 and 6

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.

  1. Check the master cylinder body for cracks. Inspect the area around the master cylinder for brake fluid. Leaks are indicated if there is at least a drop of fluid. A damp condition is not normal.
  3. Inspect the level of the brake fluid to assure it is at the correct height. Clean the top of the reservoir cap so that all dirt is removed. Remove the cap(s) or reservoir cover and the reservoir diaphragm.

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Fig. Fig. 1: Clean all of the dirt from the master cylinder cap, to avoid contaminating the system when you remove the cap

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Fig. Fig. 2: The master cylinder reservoir has MAX (1) and MIN (2) fill lines

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Fig. Fig. 3: Remove the master cylinder reservoir cap by pulling it off the top of the reservoir. Note the cap diaphragm

  1. Inspect the brake fluid level. Add clean DOT-3 brake fluid as required to bring the fluid level to the line located inside the neck of the reservoir fill opening.

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Fig. Fig. 4: Add fluid, from a fresh, sealed container, until it reaches the MAX mark on the reservoir

  1. Install the reservoir cap.

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Fig. Fig. 5: If the cap diaphragm is extended due to low fluid levels ...

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Fig. Fig. 6: ... make sure to push it back into place before reinstalling it

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.