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    Clutch Master Cylinder

    Inspect/Replace

    The clutch master cylinder is located next to the brake master cylinder. A slave cylinder is attached to the release lever at the clutch. The two cylinders are attached hydraulically by tubing and hose.

    A hydraulically operated clutch.

    To Remove:

    • Take off the reservoir cover and remove the fluid from the reservoir.
    • Disconnect any wires connected to the reservoir or master cylinder body.
    • Disconnect the tubes.
    • Remove the nuts or bolts attaching the master cylinder to the vehicle.
    • Slide the master cylinder off. If it will move only a short distance but no farther, replace one of the nuts or bolts (finger tight) to support the master cylinder and then disconnect the pushrod from the pedal. After disconnecting the clip or pin and clip holding the pushrod to the pedal, try to remove the master cylinder again.

    To Replace:

    • When installing a new master cylinder, it is a good practice to flush the cylinder with clean brake fluid. This is done to remove any debris that might be left over from the manufacturing process or chemical coatings that were used to protect the cylinder from corrosion. To flush a master cylinder, simply fill the reservoirs and the cylinder bores about one-third full with clean brake fluid, install the reservoir cover, plug the line ports, shake the cylinder to work the fluid all around, and drain out all the fluid.
    • Bench bleed the cylinder.
    • If the old master cylinder used a boot or hub seal, a new one should be installed as the master cylinder is being replaced.
    • Place the master cylinder in position, replace the mounting bolts or nuts, and tighten them to the correct torque.
    • Reconnect the pushrod to the pedal as necessary.
    • Remove the plugs or bleeder tubes from the outlet port as you connect the line. Do not tighten the line yet. Place a shop cloth under the line fitting to catch any fluid that may leak out.
    • Fill the reservoir about three-fourths full with brake fluid.
    • Have an assistant slowly push the pedal as you observe the connections a the outlet port. They will probably be leaking some fluid with air bubbles. Continue the pedal strokes until only fluid with no air bubbles leaves the connection.
    • At this point, tighten the connection with the pedal is being pushed downward.
    • Fill the reservoir to the correct level and replace the cover.
    • Reconnect any wires that were disconnected.
    • Check the brake pedal free travel and adjust it if necessary. There should be 1/16 to 1/8 in. (1.6 to 3.1 mm) of free travel before the pushrod engages the piston in the master cylinder.

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