Master Cylinder
The brake master cylinder is a dual-piston type. See Fig 1. The brake master cylinder is assisted by a power brake booster. The following conditions are considered normal and not indications that the brake master cylinder is in need of repair or replacement:
- Low brake fluid level detected without signs of leakage. This condition is caused by displacement of brake fluid to the disc brake calipers to compensate for normal brake wear. Fill the brake master cylinder reservoir with High Performance DOT 3 Motor Vehicle Brake Fluid (C6AZ-19542-AB) or an equivalent DOT 3 brake fluid meeting Ford specification ESA-M6C25-A.
- A trace of brake fluid found on the outside of the power brake booster below the brake master cylinder mounting flange. This condition results from the lubricating action of the brake master cylinder wiping seal.
The brake master cylinder fluid level warning switch is an integral part of the brake master cylinder reservoir. It consists of a float containing a magnet and a reed switch mounted in the bottom of the brake master cylinder reservoir. When the brake fluid in the brake master cylinder reservoir gets to a predetermined level, the floating magnet actuates the reed switch, causing the red brake warning indicator to illuminate. Loss of brake fluid will cause the warning indicator to activate.