REPAIR STEPS
SOLUTION
DIAGRAMS
PROBLEM
MI91.2137
11MAY98
REFER TO MP85.3462
e. The jacks do
not swing vertical,
one or more jacks
extend in the hor-
izontal position.
The foot of the
jack(s) retract after
the H/V switch is re-
leased.
Unplug the solenoid valve for the jack that is extending in the horizon-
tal position. Plug that connector onto a solenoid valve that is not ex-
tending. Push the H/V switch to VERTICAL. If the problem changes
to a different jack, the control panel or the harness is the problem. If
the jacks swing vertical and no jacks extend, the valve that is unplug-
ged should be replaced.
f. The jacks do not
swing vertical, all
four jacks extend
in the horizontal
position.
Unplug the stabilize solenoid valve. Push the H/V switch to vertical.
If the jacks go vertical, check for power between the purple and red
wire in the stabilize plug. If power is present while pushing the H/V
switch, the problem is the control harness or the control panel. If power
is not present, replace the stabilize valve. If the jacks still extend in the
horizontal position with the stabilize valve unplugged, replace the sta-
bilize valve.
REFER TO MP65.3452
GREEN
BLUE
BROWN
ORANGE
BA
BA
BA
BA
B
A
STAB.
PURPLE
BA
Part 4 continued
Unplug the H/V valve. With the system on, check for +12 on the red
wire in the female plug.
If +12 is not present, check the fuse at the fuse board for that valve.
Two valves are connected to each fuse. (Older fuse boards have
3 circuit breakers and some older boards have 2 circuit breakers
with 3 valves connected to each breaker.) If the fuse is blown (or
breaker is tripped) replace the fuse. (Let the breaker reset.) With the
system ON (leave the H/V valve unplugged) if the fuse blows again
or the breaker will not reset, the other valve connected to that fuse
(breaker) should be replaced. If the fuse does not blow, plug the H/V
valve back in. With the system on, if the fuse blows or the breaker
trips, replace the H/V valve.
If +12 is present on the red wire, check for ground on the yellow
wire in the plug while pushing the H/V switch to vertical. A test light
can be connected to the main stud on the fuse board to check for ground.
Check that the fluid reservoir is properly filled. Remove the return line
at the pump. Unplug the H/V valve. Push the H/V switch to VERTICAL.
REFER TO MP65.3455
REFER TO MP85.3462
c. The pump runs
under load. No
jacks go vertical.
d. The pump runs
under no load. The
jacks will not go
vertical, no jacks
are extending.
If the yellow wire has a ground, replace the H/V valve. If not, the yellow
wire or control panel is bad.
If fluid flows from the return line, replace the shuttle valve. If no fluid
flows from the return line, plug the H/V valve back in and try again.
If fluid flows from the return line, replace the bleed valve. If no fluid
flows from the return line, check voltage to the pump. Connect a 5000
psi pressure gauge to the pressure port of the pump. If the pressure
is less than 3000 psi, the pump should be repaired.
REFER TO MP85.3462
REFER TO MP85.3300
A
B
VERT
HOR/
YELLOW
BA
B A
HORIZONTAL /
VERTICAL
*
RED
YELLOW
REFER TO MP85.3305
LEFT
FRONT
+
+
STAB.
REAR
LEFT
+
+
FRONT
RIGHT
H/V
REAR
RIGHT
SHUTTLE
VALVE
RETURN
LINE
BA
HOR/
VERT
A
B
YELLOW
