TM-5-2350-378-24-P
HYDRAULIC DIAGNOSTIC CENTER (HDC) SUPPORTING ARMORED COMBAT EARTHMOVER (ACE), M9
TECHNICAL MANUAL; UNIT, DIRECT SUPPORT, AND GENERAL SUPPORT MAINTENANCE MANUAL INCLUDING REPAIR PARTS AND SPECIAL TOOLS LIST
TM-5-2350-378-24-P - Page 88 of 790
TM 5--2350--378--24&P
0005 00--29
USING THE HYDRAULIC DIAGNOSTIC CENTER (HDC) SYSTEM TO TROUBLESHOOT
THE M9 HYDRAULIC SYSTEM -- Continued
0005 00
Table 5. POSSIBLE SYMPTOMS OF FAILED HDC SYSTEM COMPONENTS -- Continued
HDC SYSTEM
POSSIBLE CONSEQUENCES
Solenoid Valve V11--Shutoff valve -- Left hand
suspension lower
SPRUNG MODE:
S
No impact.
UNSPRUNG MODE--LOWER:
S
No hydraulic fluid supply (17 lower) to intermediate wheel
control valve.
S
No hydraulic fluid supply (17) to left front actuator 1.
S
Inability to completely lower left front side of vehicle.
S
Degraded dozing and scraping.
UNSPRUNG MODE--RAISE:
S
No hydraulic fluid supply (17) from left front actuators 1 & 2.
S
Hydraulic fluid will return through (7).
Solenoid Valve V12--Shutoff valve --
Suspension relief valve port 9
SPRUNG MODE:
S
Inability to charge main accumulator.
S
Delayed response in suspension adjustment if
compensating pump can’t keep up with system demand.
S
Relief valve inactive.
S
Possible hydraulic system damage if compensating pump
fails to regulate pressure.
Solenoid Valve V13--Shutoff valve --
Suspension relief valve, main accumulator
SPRUNG MODE:
S
Inability to charge main accumulator.
S
Delayed response in suspension adjustment if
compensating pump can’t keep up with system demand.
Solenoid Valve V14--Shutoff valve -- Winch
control valve
S
Can’t supply hydraulic fluid to, or return fluid from, winch
motor.
S
Can’t pay out or pay in winch.
Solenoid Valve V15--Shutoff valve -- Right
hand suspension raise/lower relief
UNSPRUNG MODE--RAISE:
S
No hydraulic fluid supply (3) to right front actuators 1 & 2
through right front wheel valve.
S
Right front of vehicle cannot be raised (Was raised in
sprung mode and now supply is cut off and cannot get 3500
psi (24131.65 kPa) pressure.))
UNSPRUNG MODE--LOWER:
S
No hydraulic fluid return (3) from front actuators 1 & 2
through right front wheel valve.
S
Can’t lower right front of vehicle.
S
Can’t doze or fill load evenly.
Back to Top
