HYDRAULIC PRESSURE GAGE PANEL
Cold weather, including extreme arctic conditions, adversely affects the semitrailer
hydraulic gage readings and filter indicator. During initial start-up operations,
gages will maintain higher than normal pressure readings and the filter indicator
will read in the red. Ample time must be given, depending upon outside ambient
temperatures, for hydraulic fluid to ware before determining that a problem exists
in the hydraulic system or that the hydraulic filter is clogged.
The hydraulic pressure gages are located behind the control nodule access cover.
Access to the gages is obtained by removing the retaining pin, raising and turning
the cover hasp, and pulling downward on the cover.
When the semitrailer is loaded, the suspension pressure gages will read 1800 -
2200 psi (12411 -15169 kPa) while sitting idle. With the platform at road height, all
suspension gages should read nearly equal pressure with no gages over 2200 psi
(15169 kPa), indicating that the load center of gravity is correct.
SYSTEM PRESSURE (1). A pressure gage which indicates from 0 - 6000 psi (0 - 41370 kPa) and measures hydraulic
pressure for the overall system during APU operations. With APU running and no valves activated, this gage should read
approximately 0 - 200 psi (0 - 1379 kPa). When performing hydraulic adjustments, the system pressure may increase to a
maximum reading of 4100 psi (28270 kPa) which is system relief pressure.
Change 1 2-5