Procedure for Installing a Foot Pedal for Operating a Hydraulic Hammer on Certain 420F2, 430F2, 432F2, and 444F2 Backhoe Loaders {1435} Caterpillar

Backhoe Loader

420F2 IT (S/N: LYC1-UP; HWD1-UP)

420F2 ST (S/N: LYB1-UP; HWC1-UP)

430F2 IT (S/N: LYE1-UP; HWG1-UP)

430F2 ST (S/N: LYD1-UP; HWE1-UP)

432F2 (S/N: LYJ1-UP; HWP1-UP)

444F2 (S/N: LYL1-UP; HWS1-UP)

Reference: Special Instruction , M0065402 , "Procedure For Connecting To The Spare Fuses on F2 Series Backhoe Loaders"

Introduction

This Special Instruction procedure will instruct you how to install an electrical foot pedal on the cab floor, which when pressed will operate the auxiliary function for the hammer. The pedal is free floating and not fixed to the cab floor, so can be moved around or stored out of the way as needed.

Some operators may prefer to operate the hydraulic hammer using a foot pedal rather than the joystick thumb roller.

Do not perform any procedure in this Special Instruction until you have read the information and you understand the information.

Illustration 1	g06231397
Optional pedal assembly

Note: The auxiliary function flow control in the main control screen cannot be utilized with this pedal option. If the pedal is depressed, you will get full auxiliary flow. The flow from the thumbwheel control is not affected and will still be influenced by the flow requested in the main control screen.

Note: Before starting any work on the electrical system, make sure that the battery isolator switch is turned off, and for Tier 4 engine machines, that the amber DEF warning lamp next to the isolator key is extinguished.

Safety Section

Show/hide table

Before service work is begun, park the machine on a hard level surface. Block the wheels of the machine so unexpected movement will not occur. Unexpected movement of the machine can cause personal injury or death.

Show/hide table

Contact with loose connectors can result in electrical shock and may cause injury or death.

Show/hide table

Accidental engine starting can cause injury or death to personnel working on the equipment. To avoid accidental engine starting, disconnect the battery cable from the negative (−) battery terminal. Completely tape all metal surfaces of the disconnected battery cable end in order to prevent contact with other metal surfaces which could activate the engine electrical system. Place a Do Not Operate tag at the Start/Stop switch location to inform personnel that the equipment is being worked on.

Required Parts

Installation Procedure

The installation requires a 12 volt power supply, and a ground point. Refer to M0065402 for connecting to the spare fuses. Connection to fuse F41 (ignition fed power supply) will be needed.

Note: Use 1.0 mm (0.04 inch) (16AWG). This ensures that the cable is of sufficient size for the 15 amp fuse rating. Smaller size wires may overheat and melt.

Illustration 2	g06231470
(1) 205-1340 Operator Controls Harness As (2) 2Q-4703 Foot Pedal Switch

Connect the operator control harness assembly (1) to the foot pedal switch (2) and place the foot pedal switch (2) on the cab floor. Route the operator control harness assembly (1) through the rubber boot and under the cab floor as shown in Illustration 2.

Locate the electrical connector for the E-stick retract (432F2 and 444F2) or auxiliary (420F2 and 430F2) solenoid under the machine and disconnect the harness from the solenoid.

Illustration 3	g06251535
Wiring schematic

Fabricate a suitable harness to connect the pedal, two relays and coil between the original auxiliary solenoid and the machine harness. Refer to Illustration 3 for the wiring schematic.

The relays and coil should be tied up using the cable ties in a suitable location under the machine.

Note: The coil is used to provide a resistance back to the machine ECM when the pedal is depressed. This is to prevent unwanted ‘open circuit’ error messages.

Test and Operation

The machine should operate as normal after installation of the pedal. The thumb wheel for the e-stick / auxiliary function should operate as before.

When you press the pedal you should get full-flow of oil to the e-stick retract circuit / auxiliary function. If the e-stick extends, then you have connected to the wrong solenoid. If the hammer is installed, the hammer should operate when the pedal is depressed.

There should be no logged or active ‘open circuit’ errors when the pedal is depressed. If there is, check the wiring to the 280-7009 Coil is correct.

If there is no power supply to the pedal or relays, check the wiring to the spare fuse, and ensure a 15amp fuse is actually present at fuse 41.