Yale Material Handling Corporation Pallet Truck MPW060

NOTE: If both the contacts and the coil of a contactor need to be replaced, replace the complete contactor as described above. Replace all of the contacts for any contactor if any contact needs replacing.

Contactor removed as described in CONTACTOR REPLACEMENT.

Identification of the buss bars for correct installation.

Buss bars and nuts that fasten to the fixed contacts removed.

Two screws that fasten the cover to the contactor removed.

Cover of the contactor removed without losing the plunger springs.

Four fixed contacts in the contactor cover replaced.

Two plunger assemblies and movable contacts removed and three fixed contact bars replaced.

Contacts of the plungers replaced.

Move key to OFF position and disconnect the battery

WARNING: The capacitor in the motor controller can hold an electrical charge after the battery is disconnected. To prevent electrical shock and injury, discharge the capacitor before inspecting or repairing any component in the drive unit compartment. Wear safety glasses. Make certain the battery has been disconnected.

Use a screwdriver or jumper wire to make a short-circuit across the B+ and B-terminals of the motor controller

Loosen the two capscrews retaining the hydraulic unit to the frame and tip the hydraulic unit toward the front of the lift truck

Remove the two capscrews retaining the cover to the motor and remove the cover

Measure the brushes. The brushes should be a minimum of 7 mm (0.275 in) in length at the smallest point

Replace the brushes as a set and inspect the springs for damage from heat (color changes) and corrosion. Replace any damaged springs

Install the cover and the two capscrews to retain the cover

CAUTION: Improper adjustment of the fork height can cause excessive wear to one of the load wheels and poor pallet entry and exit.

Lower the forks completely (the cylinder should be bottomed out).

On early production models, remove the four capscrews retaining the access covers on each fork. Late production models do not have an access cover.

Loosen the nuts on the pull rod on each side of the pull rod yoke.

Ensure that load wheel supports are completely lowered. Check that the top of the load wheel support is flush with the underside of the fork weldment.

Adjust the rear fork height adjustment screws on each side, with the battery in place, to obtain a fork height of 85.9 to 88.9 mm (3.38to 3.5 in) at the rear of the forks.

Adjust both outer jam nuts and adjust the inner jam nuts to obtain a fork height (measured at the front of the forks) of 82.5 to 84.1 (3.25 to 3.31 in).

Ensure that the measurements are the same on each side and that the forks lift at the same time.

After the adjustments have been made, tighten the jam nut(s)to 176 N«m (130 Ibf ft) torque.

WARNING: Put blocks under each side of the truck under the drive unit frame. Position blocks on both sides of the load wheels. The blocks must prevent the lift truck from falling and causing injury or damage.

Raise the drive wheel off the floor. Block the lift truck. See Section 1-HOW TO PUT A LIFT TRUCK ON BLOCKS. Disconnect the battery.

Remove the drive unit compartment cover. Refer to Section 2-DRIVE UNIT COMPARTMENT COVER-REMOVAL AND INSTALLATION.

WARNING: The capacitor in the motor controller can hold an electrical charge after the battery is disconnected. To prevent electrical shock and injury, discharge the capacitor before inspecting or repairing any component in the drive unit compartment. Wear safety glasses. Make certain the battery has been disconnected.

Discharge the capacitor in the motor controller.

If used, remove the brush covers to the motor. Wear eye protection. Use a vacuum cleaner or compressed air to remove dirt and 'brush dust' from the commutator area.

Visually inspect the commutator surface. Refer to Figures 3-20 through 3-28. The commutator wears slowly in normal service. The mica must be cut below the surface of the commutator bars after a long service period or after a commutator has been turned in a lathe. Carefully rotate the armature. DO NOT damage the commutator if you use a tool to rotate the armature.

Inspect the white or gray insulation (mica) between the commutator bars. The mica must not touch the brushes or the brushes will wear very rapidly.

Install the brush covers, when used and the drive unit compartment cover. Refer to Section 2-DRIVE UNIT COMPARTMENT-REMOVAL AND INSTALLATION.

WARNING: The capacitor in the motor controller can hold an electrical charge after the battery is disconnected. To prevent electrical shock and injury, discharge the capacitor before inspecting or repairing any component in the drive unit compartment. Wear safety glasses. Make certain the battery has been disconnected. Use a screwdriver or jumper wire to make a short-circuit across the B+ and B-terminals of the motor controller.

Motorized hand trucks use a single 15 amp fuse for the control circuit, and 200 amp fuses for both the hydraulic pump motor and the drive motor. The fuses are located on the contactor panel.

15 amp fuse for the control circuit checked

200 amp fuse for the hydraulic pump motor checked

200 amp fuse for the drive motor checked

Remove and replace as required. If it cannot be determined visually that a fuse has failed, check for continuity using an ohmmeter.