MD Helicopters MD Explorer - Fault Isolation; Hydraulic System Troubleshooting

CSP−900RMM−2MD Helicopters, Inc.
Rotorcraft Maintenance Manual
Page 101
Original
29-00-00
HYDRAULIC SYSTEM
FAULT ISOLATION
1. Hydraulic System Troubleshooting
(Ref. Figure 101 and Figure 102)
The following troubleshooting procedures are a
brief summary of hydraulic system faults,
which may be encountered (Ref. Table 101).
Troubleshooting tables should be used with
system schematics, electrical wiring diagrams,
serviceability checks and other detailed
procedures in this and other chapters of the
manual.
Comprehensive wiring diagrams are available
in the Rotorcraft Maintenance Manual
CSP-900RMM-3 (Ref. Section 98-40-00).
Table 101. Hydraulic System Troubleshooting
Fault Probable Cause Corrective Action Ref. Section
1 HYD and HYD 2 not
present on IIDS during
System 1 and System 2 self
test.
Faulty K1−7/8 AOG relay. Replace relay K1−7/8. 96−30−00
28 vdc not present at
K1−7/8−B2.
Test and repair wiring. 98−00−00
CB 48 inoperative. Replace circuit breaker. 96−30−00
Faulty switch S5 A606 Utility
Control Panel.
Replace switch. 96−30−00
1 HYD not present on IIDS
during System 1 self test.
Open ground between
GS107−J and P429−B.
Test and repair wiring. 98−00−00
Faulty test solenoid. Replace solenoid.
28 vdc not present at
K1−7/8−B2.
Test and repair wiring. 98−00−00
CB 48 inoperative. Replace circuit breaker. 96−30−00
Faulty switch S5 A606 Utility
Control Panel.
Replace switch. 96−30−00
1 HYD present on IIDS
during System 1 self test, but
no pressure reading below
250psi present on alpha
numeric IIDS display.(With no
IIDS SENSEFALT BIT 15
=7.5V EXCITATION failure.)
Faulty pressure transducer
on A400 hydraulic manifold
1.
Replace transducer. 96−30−00
Faulty wiring between A400
hydraulic manifold 1 P428
and A2 IIDS P102.
Test and repair wiring. 98−00−00
1 HYD present on IIDS and
low pressure reading present
on alpha numeric display.
Faulty pump. Internally
worn.
Test pump output pressure with
mechanical gauge and repair or
replace pump as necessary.
29−00−00
Loose / broken fitting or
cracked/broken line.
Repair/replace fitting/line. 29−00−00
Leaking actuator. Repair/replace actuator. 67−10−00