Table 4. Possible Symptoms Of Failed HDC System Components - Continued.
Solenoid Valve V17 - Shutoff valve - Apron retract
No hydraulic fluid supply going to (raise) or from
(lower) apron cylinders.
Apron cannot be raised or lowered.
Cannot unload or cannot retain load in bowl.
Solenoid Valve V18 - Shutoff valve - No. 4 actuator, left
suspension port 9 to port 2 (normally closed)
Compensating pressure continuously supplied
to left rear actuators 3 & 4.
Compensating pressure at 2850 psi (19650.06
kPa) continuously supplied to left rear actuators
3 & 4 and right rear actuators 3 & 4. If this is
normal pressure in unsprung mode, there is no
Solenoid Valve V19 - Shutoff valve - Suspension relief
valve port 17R (normally closed)
Compensating pump pressure is directed to
No hydraulic fluid supply (9) to wheel valves.
No hydraulic fluid supply (9) to actuators.
Vehicle will not be raised.
Track may be thrown if vehicle is backed.
No suspension shock absorbing capability.
Main accumulator/compensating pump
pressure is directed to right front intermediate
Main accumulator pressure is directed to right
front actuator lower side.
No vehicle change in height since raise side
pressure is trapped.
Hydraulic fluid supply is directed to return.