Usage:
Dash Switch
1. Install the dash switch in a convenient location in the cab. Carefully measure and cut all harnesses to proper length. Thread wires through the loom provided. Install receptacles at locations shown in wiring diagram furnished in the kit.
Clutch Switch
The optional overtravel bracket should be used when the clutch switch is installed in the wheel well location or a location where a build up of road contamination (ice, mud, etc.) can stick to the actuator arm.
1. Mount the clutch switch in the most convenient or accessible location possible. Locations may include in cab under dash, under floor wheel well location, or in the area of the bell housing.
2. Install this switch with the switch actuator arm in contact with the clutch pedal arm or other clutch member.
3. Adjust the switch by moving the switch along the mounting bracket. The actuator arm should be deflected 1.0 - 1.5 inches (25 - 38 mm), measured at the tip of the actuator, when the clutch pedal is in the up (clutch engaged) position.
4. Check installation by moving the clutch pedal. The switch should click in the freeplay motion of the clutch pedal before actual clutch disengagement takes place.
NOTE: This adjustment should allow the switch to work the freeplay of the clutch pedal before actual clutch disengaging takes place.
5. Cut wires to proper length and secure them with ties. Connect the wires. Black lead to power source.
1. Remove the fuel pump low idle screw. On 3406B engines, install the seal, washer, gasket and locknut from the low idle screw on the switch. On 3406 engines, install the Jacobs locknut and seal washer on the switch. Insert the switch to about the same depth as the idle screw was.
Start engine and check low idle RPM. Disconnect the throttle linkage and adjust the idle per Caterpillar specification by turning the switch clockwise to increase and counter-clockwise to decrease engine RPM.
When proper RPM is set, advance the throttle lever to increase engine speed and then return to idle. Check to be sure the idle RPM setting did not change. Readjust if necessary.
2. Hold the Jacobs switch and tighten lock nut to 5 lbft (7N·m). Reconnect throttle linkage. Connect leads to the proper switch terminals. The brass terminal is positive. Follow the wiring diagram.
NOTE: The internal switch for the 3406B engine is different from the internal switch on the 3406 engine.
Actuating Arm Switch Assembly
The earlier type of fuel pump switch (shown above), if used, is adjusted by positioning the actuating arm on the fuel pump governor to a point where you hear a "click" when the throttle arm moves to an idle fuel position.
| NOTICE |
|---|
CHECK TO BE SURE THAT THE GOVERNOR OPERATING LEVER MOVES FREELY FROM LOW IDLE TO HIGH IDLE POSITION AND RELEASES WITHOUT BINDING. |
Final Wiring
1. Complete the wiring. Refer to the wiring diagram.
2. Check all wiring. Make sure all wiring has been cut to correct length, installed properly, tied off, and moved out of sight. Wires should be routed where no chafing, mechanical interference, or similar interference can occur. Generally, a malfunctioning engine brake is due to faulty or careless wiring.
3. With the engines shut down, check electrical system by turning on ignition switch and moving Jacobs dash switch from OFF to LO to HI. In LO, only the rear brake housing solenoid valve should activate. In HI, both front and rear solenoids should activate.
4. Finally, attach the OPERATING INSTRUCTION decal in a convenient location on the dash. Then complete and mail the Engine Brake Warranty card.
