STINAR PS-813B/E - Page 28

Passenger Stairway PS-813B/E Boeing | 28
SECTION 2 - SERVICING PASSENGER STAIRWAY
TROUBLE PROBABLE CAUSE REMEDY
Stairway or A-frame
raises, but will not
lower
Safety ratchet engaged
Raise stairway or
A-frame slightly
and release ratchet
manually
Control valve problem Repair or replace
Lock valve problem
Repair or replace lock
valve
Stairway or A-frame
lowers too fast
Flow control valve needs
adjustment
Adjust ow control
per Section 3
Stabilizers fail to
extend
See stairway or A-frame
will not raise
See stairway or
A-frame will not raise
Stabilizers lose
pressure
Leaks in system
Locate and repair
leaks
Cylinder internal leaks Repair cylinder
Hand pump fails
to power stairs or
A-frame
Leakage in hydraulic lines
or ttings
Tighten or replace as
necessary
Check valve defective
Clean, repair or
replace check valve
Defective hand pump Repair or replace
Electrical system (see Figure 2.2.1.2)
Engine will not
crank
Batteries discharged Recharge batteries
80 amp. circuit breaker
tripped
Locate and repair
source of overload
and reset circuit
breaker
Battery cables loose or
terminals corroded
Tighten cables and
clean terminals
Engine problem
See engine
troubleshooting
WARNING!
Always disconnect 120 VAC
external power source before
making electrical repairs.