Genuine Mercury Mariner Brake Master Cylinder

Mercury Mariner Brake Master Cylinder Parts Questions & Answers

• Kit - Master Cylinder Repair
  8L8Z-2140-A
  Q: How is the master cylinder removed from the engine compartment?

  A: The brake master cylinder, located in the engine compartment and attached to the power Brake Booster, is removed by first extracting as much fluid as possible from the reservoir using a syringe. The area is then prepared by placing rags underneath and prepping caps or bags to cover the Brake Lines once disconnected, taking care to avoid spilling the brake fluid which can damage paint. On manual transaxle models, the clutch master cylinder supply hose is detached from the brake fluid reservoir. Next, the fittings at the ends of the brake lines are loosened where they enter the brake master cylinder, using a flare-nut wrench to prevent rounding off the corners of the nuts. The brake lines are then pulled slightly away from the brake master cylinder and the ends plugged to avoid contamination. The electrical connector at the brake fluid level switch on the brake master cylinder reservoir is then disconnected, and the nuts attaching the brake master cylinder to the power booster removed. The brake master cylinder is then carefully pulled off the studs and out of the engine compartment. If a new brake master cylinder is being installed, the reservoir is removed from the brake master cylinder and transferred to the new one, taking care to install new seals during the transfer. Before installing, the new brake master cylinder is bled by mounting it in a vise and attaching bleeder tubes to the outlet ports. The reservoir is filled with recommended brake fluid, and the pistons slowly pushed into the brake master cylinder using a large Phillips screwdriver until no more air bubbles are present. The bleed tubes are then removed, and plugs installed in the open ports to prevent fluid leakage and air intake. The brake master cylinder is then installed over the studs on the power brake booster, with the attaching nuts tightened only finger tight. A new O-ring is installed into the sleeve of the brake master cylinder, and the brake line fittings threaded into the brake master cylinder, with the fittings tightened to avoid stripping the threads. After filling the brake master cylinder reservoir with fluid, the brake master cylinder and brake system are bled by having an assistant depress the brake pedal and hold it to the floor while loosening the fitting to allow air and fluid to escape. After rinsing the area under the brake master cylinder with clean water, the operation of the brake system is carefully tested before resuming normal service.