Hydraulic Pump Testing (A.12.A.20 - G.40.A.20) - New Holland CX720 Repair Manual

DISTRIBUTION SYSTEMS - SECONDARY HYDRAULIC POWER SYSTEM
Hydraulic pump - Testing (A.12.A.20 - G.40.A.20)
NOTE: Low Pressure Warning 'ON'
N° Test Point
1 Does the Chaff blower motor func-
tion correctly?
2 Disconnect the wiring to the low
pressure warning switch. Does the
light still illuminate?
3 Perform the low pressure circuit
pressure test. Is the pressure 25
bar (362 psi) ?
4 Was the pressure measured 0 Bar? YES
5 Suspect the drive link between the
CCLS and low pressure pumps.
Remove the low pressure pump and
inspect. Is the drive link okay?
6 Suspect a leak within the low pres-
sure block. Remove each solenoid
valve and Inspect for sticking spools
or dirt ingress.
Clean or replace as required.
Check the operation. Is the pressure
to the specification?
7 Remove and Inspect the relief valve
in the low pressure block. The valve
may be stuck open. clean or replace
as required.
Check the operation. Is the pressure
to the specification?
Expected Result
YES
Go to test 2
YES
Wiring fault to switch.
Trace and repair short circuit in
wiring
YES
Suspect a faulty switch.
Replace and check operation.
Go to test 5
YES
Go to test 7
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Other Result (Possible Cause)
NO
Go to test 3
NO
Go to test 3
NO
Go to test 4
NO
Go to test 6
NO
Suspect a faulty pump. Remove and
Inspect. Repair or replace the pump
as required and recheck.
NO
Suspect a faulty pump. Remove and
Inspect. Repair or replace the pump
as required and recheck.