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Hydraulic system maintenance
Telescopic cylinder
Check your cylinder periodically for oil leaks. A damp to light film of oil on the cylinder indicated good
cylinder operation. After numerous cycles of the cylinder, a small accumulation of oil may be noticed and
should not be mistaken for leakage around the stage packing.
The special recycling valve that is equipped on this system allows the tank to be completely full. The tank
may be from ¾ full to completely full. Do not let the fluid volume go below ¾ full.
It is recommended that field service repairs to the cylinder be limited to adjusting packing. If other damage is
apparent, contact PRATT.
Cylinder sleeve
The cylinder sleeve should be checked periodically for damage. Any burrs or scratches found should be
removed with a honing stone or emery cloth to prevent damage to the packing assembly.
Fittings, hoses and pipes
Visually inspect fittings, hoses, and pipes for leaks, abrasions, crimping, breaks, cracking, or other
deterioration. Replace immediately if any of the above signs of deterioration are visible.
Lighting maintenance
Lights and wiring
The lighting system for your trailer is a heavy duty, 12-volt, 30 amp system. The 7way receptacle is located
on the front of the trailer near the gladhands. The jumper cable from the truck tractor plugs into the trailer's 7-
way receptacle to complete the electrical circuit to the trailer. The receptacle is equipped with a hinge type
cover to protect it from exposure to dirt and water. Trailer lights are controlled by the same light switches that
control the lights on the truck tractor.
Proper maintenance of the lighting system requires periodic cleaning of lamps and reflectors to assure
maximum visibility of the tractor and trailer. Use a damp cloth to wipe the lenses. A dry cloth will cause the dirt
to act as an abrasive and scratch the lenses. A daily cleaning can well be worth the time invested, plus, it is a
good safety practice. Maintenance of the lighting and wiring system consists of an occasional inspection to see
that all wiring connections are tight. Make sure the lighting units are securely mounted, and that the wiring is
not pinched or damaged. Inspect lights, couplings, and sockets for their serviceability and replace as required.
CAUTION!
CONNECTOR WIRING CHANGE: Notice to ALL Tractor Trailer Owners
&
Users: Federal Motor Vehicle
Safety Standard No. 121, Air Brake Systems, was amended by the National Highway Traffic Safety
Administration of DOT to require that truck tractors manufactured on or after March 1, 1997 provide
constant power for a trailer's antilock brake system (ABS). Some manufacturers will provide this feature
before the effective date.
These tractors using a single 7-way electrical connector will have constant power for ABS on the center pin
when the key switch is on.
PRATT, as well as other tractor-trailer manufacturers and users who presently use the center pin for auxiliary
power to equipment other than trailer ABS (for example, dome lights, backing light, bottom dumps, sliding
undercarriages, air ride dump valves, etc.) will be affected by this change.
In certain uses of this constantly powered center pin connector, unexpected or unintended activation of this
equipment may be hazardous or result in personal injury.
BEFORE
connecting your trailer to a tractor, MAKE SURE that the constantly powered center pin WILL NOT
UNINTENTIONALLY TURN ON TRAILER EOUIPMENT. If you have any questions about your present wiring,
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