19295-ZY6-000 Honda COVER, RELIEF VALVE (Honda Code 7634363).

Introduction
This instruction provides the necessary parts and installation information required to remove the potentiometer system in the controller and replace it with a Read Only Memory (ROM) kit.This replacement procedure is recommended, because of the potential problems associated with the potentiometer system. The potentiometer may develop a poor contact internally which may cause engine stall or reduced pump output. Current production machines are equipped with the "Potentiometer-less Controller".To expedite the replacement, remove the controller and parts specified in this instruction and install a modified replacement controller (part no. 861871).Because of the possibility of damage to the ROM kit, modify the old controller in a "CLEAN" environment using the instructions in this publication.After completing the modification in a "CLEAN" environment, the controller can be tested using the 1R9803 Power Box.The 1R9803 Power Box is a testing device used to simulate machine functions to allow the controller to be tested in the shop without installation on the machine. This Special Instruction includes the test procedure using the 1R9803 Power Box.This modification is applicable to all of the E200B and EL200B Hydraulic Excavators listed above.* E200B (6KF0034-0433) currently uses the 991108 Controller.* E200B (6KG0034-0249) currently uses the 856951 Controller.* EL200B (7DF0068-0962) currently uses the 856950 Controller.* After modification, the controller will be identified by an 861871 part number.Do not perform any procedure, outlined in this publication, or order any parts until you read and understand the information contained within.Reference: Parts Manual and Service Manual.Tools Needed
6V3121 Multitach Group6V4161 Pressure Gauge GroupT-slot screwdriverPhillips screwdriver If the machine is equipped with air conditioning, a special Phillips screwdriver must be fabricated to facilitate removal of the controller.
(A) Special Phillips screwdriver. (B) Air conditioner, reference only. (C) Fillet weld.A size three (3) Phillips screwdriver is needed to protect the bolt head when loosening or tightening. Fabricate the special screwdriver as shown in the illustration. Make a fillet weld at location (C).Parts Needed
* 862519 ROM kit; which includes a ROM chip a model identity label and a new ROM label.* 7Y6172 Label* 857462 Shorting Connector.* 3S2093 Tie Wraps (as needed).Installation
1. Turn the main power off. 2. Disconnect the connector from the controller by depressing tab (D) with your finger and moving the connector side to side while pulling on the connector body. To avoid breaking any connections, do not pull on the wiring. 3. Remove the bolts holding the controller to the support, and remove the controller.4. Install new controller and connect the wiring connector.5. Remove the following parts from the engine control and discard. These parts will not be used with the converted system.
(A) 857462 Connector. (B) Tie Wraps.6. Connect the 857462 Shorting Connector (A) to the free end of the potentiometer harness and secure it in position with 3S2093 Tie Wraps (B).7. Turn on the main power.Adjusting the Control
Engine Control Operation at Low Idle.
(1) Governor Control Lever. (2) Stop. (3) Governor Lever. (4) Lever. (5) Lever. (6) Cable. (7) Stop.1. Place engine control lever (1) in the Low Idle position. Make sure that governor lever (3) is placed in the idle position. Lever (4) must be in contact with stop (7) of lever (5). Adjust cable (6) so that the cable has no slack at locations (F) and (G).
Engine Control Operation at Hi Idle.
(1) Governor Control Lever. (2) Stop. (3) Governor Lever. (4) Lever. (5) Lever. (6) Cable. (7) Stop.2. Place the governor control lever in the Hi Idle position. Stop (2) must not be in contact with the governor control lever. Adjust the position of stop (2) according to the following procedure:a. Make sure that lever (3) has moved full travel.b. Pull lever (1) further and turn lever (4) clockwise until the clearance between lever (4) and stop (7) is 1 mm (.04 in). Secure a feeler gauge of the correct dimension in position.c. Turn stop (2) bolt inward until stop (2) is in contact with lever (1). Tighten the locknut to lock the stop in position.d. Remove the feeler gauge.e. Return the governor control lever to the Low Idle position.
Controller Assembly.
(8) LED Display. (9) Switch. (10) Switch.3. Remove the controller cover so that switch (10) and switch (9) can be operated and so that LED display (8) can be observed.4. Turn on the start switch.5. Start and run the engine at Full speed.6. Turn the AEC Switch to the OFF position.7. Press both switches (9) and (10) at the same time and hold for more than three seconds. Release both switches when LED's (3) and (4) start flashing. Then press both switches (9) and (10) again for about one second. LED (7) will light.Press switch (10) for three seconds. LED (3) will stop flashing and LED (4) will remain lit. This indicates that engine high idle speed has been inputted.Calibration of Proportional Reducing Valve
Main Pump.
(11) Tap.1. Attach a 4000 kPa (580 psi) pressure gauge to tap (11) of the main pump.2. Set the power mode switch to the III mode.3. Turn the AEC switch to the OFF position. Start the engine and move the governor control lever to High Idle. Check to see that LED (4) is on, indicating that the controller is in operation.4. Press and hold switch (9). 5. The power shift pressure changes in seven steps. When the pressure reaches 2250 100 kPa (330 14 psi), press switch (10) for about one second.6. Release switch (9) to complete the calibrating operation.7. Move a control lever (bucket, for example) full stroke once or twice.8. Make sure that the power shift pressure is 2250 100 kPa (330 14 psi) when the control lever is in the Neutral position. If out of specification, repeat the adjustment again.9. Make sure that only LED (4) of 1 to 4 lights. This indicates a Normal status.
Proportional Reducing Valve.
(12) Adjusting nut. (13) Connector. (14) Solenoid. (15) Reducing Valve. (A) Passage (power shift pressure). (P) Passage (pilot circuit pressure). (T) Passage (oil tank line).In rare cases, the above procedure may fail to provide the standard power shift pressure of 2250 100 kPa (330