TM 5-2420-231-23-1
0076
Table 1. Backhoe Boom Does Not Operate Correctly - Continued.
076
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
Backhoe Boom Does Not
Test Step 4. Check Pilot Control
Operate Correctly -
Pressure.
Continued
Perform pilot pressure test (WP 0086). Pilot Control Pressure 350 to 550 psi
- Disconnect hose and pressure gauge
from machine.
Proceed to Test Step 5.
Pilot Control Pressure Less Than 350
psi - Disconnect hose and pressure
gauge from machine.
Replace pilot control valve assembly
(WP 0264).
Proceed to Test Step 6.
Test Step 5. Check Joystick Control.
1. Perform pilot control valve test
Any Pilot Control Flow Greater Than
1 gpm - Perform Flowmeter Disconnect
Procedure (WP 0086).
Replace backhoe control valve
assembly (WP 0263).
Proceed to Test Step 6.
Any Pilot Control Flow Less Than 1
gpm - Proceed to step 2.
2. Push control pattern switch to Pat-
tern 2 (TM 5-2420-231-10).
3. Operate backhoe boom (TM 5-
Backhoe Boom Cylinder Operates
Normally - Perform Flowmeter
2420-231-10). Monitor and record
Disconnect Procedure (WP 0086).
machine operation.
Replace right-side joystick control valve
assembly (WP 0266).
Proceed to Test Step 6.
Backhoe Boom Will Not Operate -
Perform Flowmeter Disconnect
Procedure (WP 0086).
Replace backhoe control valve
assembly (WP 0263).
Proceed to Test Step 6.
Test Step 6. Verify That Symptom Is
Resolved.
Operate backhoe boom (TM 5-2420-
Backhoe Boom Cylinder Operates
231-10). Monitor and record machine
Normally - Troubleshooting complete.
operation.
Backhoe Boom Cylinder Operates
Slowly - Repeat troubleshooting from
the beginning.
Backhoe Boom Will Not Operate -
Repeat troubleshooting from the
beginning.
END OF WORK PACKAGE
0076-5/(6 blank)
