Help change master cylinder on 1991 Nissan truck?

Answer 1

REMOVAL & INSTALLATION

Be careful not to spill brake fluid on the painted surfaces of the vehicle, as it will damage the paint.

1. Unfasten the hydraulic lines from the master cylinder.
2. Disconnect the hydraulic fluid pressure differential switch wiring. On models with fluid level sensors, also disconnect the fluid level sensor wiring.
3. Loosen the master cylinder reservoir mounting bolts.
4. On models with manual brakes, unfasten the master cylinder securing bolts and the clevis pin from the brake pedal, then remove the master cylinder. On models with power brakes, unfasten the nuts and remove the master cylinder assembly from the power brake unit. To install:
   1. Install the master cylinder in reverse order of removal and note the following:

      Many models have an UP mark on the cylinder boot; make sure it is in the correct position.Before tightening the master cylinder mounting nuts or bolts, screw the hydraulic lines into the cylinder body a few turns.After installation is completed, bleed the master cylinder and the brake system.Check and adjust the brake pedal as necessary.When replacing the the master cylinder, it is best to BENCH BLEED the master cylinder before installing it to the vehicle. Mount the master cylinder into a soft-jawed vise or suitable equivalent, so as not to damage the cylinder. Fill the cylinder to the correct level with new DOT 3 type brake fluid. Block off all the outer brake line holes but one, then position a long wooden dowel in the bore to actuate the brake master cylinder. Pump the brake master cylinder 3 or 4 times (push in and out with the dowel) until brake fluid is released and no air is in the brake fluid. Repeat this procedure until all brake fluid is released from every hole and no air is expelled.