How to Replace the Brake Master Cylinder on a 1995 Nissan Altima

The brake master cylinder stores the brake fluid. It is mounted within the engine compartment on the brake booster, which sends the fluid through the brake lines. Replacing the master cylinder in the 1995 Nissan Altima is very much the same as with any other vehicle, as auto braking systems have not changed much. Your main concern will be locating a shop that can get the exact type of cylinder used by this car. You need to replace this component if it is leaking fluid or is otherwise damaged.

Instructions

Disconnect the car's negative battery cable.

Disconnect the electrical harness for the brake fluid level sensor from the master cylinder reservoir.

Disconnect the two brake fluid lines from the cylinder, loosening their connecting nuts with a flare-nut wrench. These lines are at the front end of the cylinder, one on the top and one at the bottom. Cap these lines with small caps or tape.

Remove the mounting nuts for the master cylinder using your wrench and remove the cylinder off of the brake booster.

Apply 19 inches of Mercury to the brake pushrod with a vacuum pump and measure the rod's length from its end to the brake booster's front face (if the rod is adjustable). It needs to be between .4045 and .4144 inches.

Install the replacement master cylinder on the brake booster and tighten its mounting nuts to between 9 and 11 foot pounds with a torque wrench if possible.

Connect the brake lines to the cylinder and tighten their fasteners to between 11 and 13 foot pounds.

Fill the master cylinder and reservoir with fresh brake fluid using an unused turkey baster or similar siphon tool, filling it to within a quarter inch of the reservoir's top edge, and then bleed the brakes as described below.

Reconnect the battery cable and the electrical harness for the brake fluid level sensor.

Raise the car and support it on jack stands, then remove all four wheels.

Connect a small length of rubber tubing to the right rear wheel's brake bleed screw, which is on the brake drum backing plate. Dip the tube's other end in a small container with brake fluid.

Loosen the bleed screw with a line wrench and have another person press down on the brake pedal to send air out the tube into the container. Close the screw and have the assistant release the pedal.

Repeat Step 3 until you see no air bubbles at all when your assistant presses the pedal, then close the screw for good and remove the tube.

Repeat all of these bleeding steps for the left rear wheel, the right front and the left front one in that order. On the front wheels, the bleed screw is at the top of the brake caliper.

Reconnect all the wheels and lower the car after bleeding the brakes at every wheel.