cylinder bracket assemblies so that all lube fittings can
be reached from the deck.
PROTECTING OPEN EQUIPMENT.—When
removing a component from the hydraulic system, cap
or plug all openings to prevent entry of foreign matter.
Use tape to protect pipe threads.
CLEANING.—Hydraulic
system
components
must
be
disassembled,
cleaned,
repaired,
and
reassembled as specified in the operation, maintenance,
and overhaul instructions manual for the specific type
of JBD installation on your ship.
WARNING
Before
repairing
or
removing
any
components connected to hydraulic or water
lines, make sure the lines are depressurized.
Also, before repairing or removing any elec-
trical component, de-energize the electrical
circuit and attach an out-of-service tag.
HOSES, SEALS, AND O-RINGS.—Hoses,
seals, and O-rings are selected on the basis of their
compatibility with the hydraulic fluid. Therefore,
replacement parts should be of the same material as
original parts. O-rings must be removed and replaced
with care to avoid damage to the O-ring and O-ring
sealing surfaces of the various parts. O-rings must be
free of cuts and not deformed. New O-rings must be
installed at every reassembly of components. Before
assembly, all O-rings must be lightly lubricated with
the system hydraulic fluid. Hoses are subject to wear
and require periodic replacement. When installing
hoses, take care to avoid unnecessary bends and
overstressing.
To restore the JBD system to operating condition
after a down period that required draining fluid,
perform preoperational inspection procedures given in
the applicable MRC.
For most repairs to the hydraulic system, only
portions of the system need be drained. Isolation valves
in each of the hydraulic cylinder lines and a shutoff
valve between the stack valve and the catapult pumps
permit isolation of portions of the JBD hydraulic
system.
Troubleshooting
Most problems that occur on JBDs can be
recognized
as
a
failure
of
one
of
three
systems—namely, hydraulic, electrical, or water.
Information that allows operating and maintenance
personnel to locate the source of problems or
equipment failure is found in the JBD technical manual,
in the section covering trouble shooting.
SAFETY PRECAUTIONS
The energy required to operate the JBD is supplied
by fluid under pressure; therefore, when operating with
fluid
under
pressure,
observe
standard
safety
precautions that apply.
All moving parts and equipment should be checked
for rags, tools, or other foreign material before
operating any of the machinery. Only qualified
operators shall be allowed to operate the JBDs.
The parking of aircraft on the deflector panel
should be avoided. The panels are designed to
withstand only the temporary weight of the aircraft
taxiing over them.
When you perform maintenance on the JBD,
comply with the safety precautions listed on the MRC.
Personnel and equipment shall be clear of the JBD
machinery enclosure and depressed deck when the
panels are being raised or lowered. This includes the
times when the panels are being operated during
preoperational
inspections
and
maintenance
or
overhaul tests and inspections.
REVIEW QUESTIONS
Q1.
What provides the means of physically raising
and lowering the JBD panels?
Q2.
Each Mk 7 Mod 0 JBD panel assembly
consists of how many tube assemblies?
Q3.
What permits rotational movement of the
piping as the JBD is raised and lowered?
Q4.
What is the maximum temperature of the
cooling water?
Q5.
What controls the hydraulic fluid to and from
the hydraulic cylinders?
Q6.
What type of valve is the stack valve?
Q7.
What is the differences between the deckedge
and the auxiliary control panel?
Q8.
The double indicator light will provide what
indication?
Q9.
What is the function of the “all” raise switch
on the chestpack portable control?
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