HYDRAULIC PRESSURE GAGE PANEL (CONT)
FRONT CURBSIDE SUSPENSION (2) AND FRONT STREETSIDE SUSPENSION (3). Pressure gages which indicate
from 0 - 6000 psi (0 - 41370 kPa) and measure hydraulic pressure for the front curbside suspension circuit (three front
curbside bogies and curbside gooseneck cylinder when gooseneck isolation valve is in the RUN position). When
semitrailer is unloaded and valves are not being operated, these gages normally read 700 -1100 psi (4826 -7585 kPa).
When raising either curbside or streetside front suspension, the respective gage will increase to a maximum of 4100 psi
(28270 kPa) when the suspension tops out. When lowering either curbside or streetside front suspension, the pressure
will decrease to 0 psi (0 kPa) when the suspension bottoms or the weight is supported by the front and rear support legs.
REAR SUSPENSION (4). A pressure gage which indicates from 0 - 6000 psi (0 - 41370 kPa) and measures hydraulic
pressure for the rear suspension circuit (four rear bogies). When semitrailer is unloaded and the rear suspension valve is
not being operated, this gage normally reads 700 - 1100 psi (4826 - 7585 kPa). When raising rear suspension, the
pressure will increase to a maximum of 4100 psi (28270 kPa) when the suspension tops out. When lowering rear
suspension, the pressure will decrease to 0 psi (0 kPa) when suspension bottoms or weight is supported by support legs.
HYDRAULIC FILTER GAGE (5). A colored gage used to identify blockage or contamination in the hydraulic filter element.
The normal indication while APU is running should be in green zone. If reading is in yellow, the element is starting to
become contaminated and should be replaced no later than the next scheduled maintenance. If reading is in red zone,
the filter is contaminated and should be replaced. In cold weather conditions, the gage will read out of green zone until oil
has warmed to normal operating temperature.
STEERING PRESSURE INDICATOR (6). Lights when the hydraulic pressure in the automatic steering system drops
below 68 psi (470 kPa) and the running light circuit is powered. Once precharge pressure is restored to the steering
system, by running the APU and momentarily operating the steering control valve in both directions, the light will go out.
2-6 Change 1