over slowly with engines idling, to draw oil into them.
4-77. Steering System Filters and Strainers
When pumps have taken a suction, reconnect discharge
a. Filters (Return Line). Refer to figure 2-8.1 for
lines and close one ball valve in the pump discharge line.
service of return line filter.
This directs oil to the remainder of the hydraulic system.
Continue filling the expansion tank and venting the
b. Suction Strainer, Hull Numbers 8500 thru 8519.
storage tank throughout the filling operation.
(1) This strainer is located inside the 10gallon
(3) Oil levels will drop as lines, valves, and
storage tank in the engine room. See figure 2-16. The
cylinders become filled. Air displaced by the oil will collect
shiner element should be removed and cleaned after the
in the storage tank and must be vented off. Turn pumps
first 25 hours and thereafter every 500 hours of
over at engine idling speed while continuing to purge the
system. When pumps and lines up to the helm unit
(2) Oil should be changed when the suction
appear to be full, rotate the steering wheel from hardover
strainer is cleaned. Continued coloration of the oil or
to hardover to work air out of cylinders and the lines
known contamination is cause for changing oil prior to
leading to the helm unit. Air may be removed from the
the regular interval.
cylinders by backing off the air bleed Allen screws
(3) Drain oil from 10-gallon storage tank (fig. 2-16).
located on the cylinder walls near the end caps. Air in the
hydraulic system will cause a spongy feeling in the helm,
(4) Remove storage tank top cover. Turn
noisy operation, and/or rapid fluctuation of oil level in the
suction strainer retaining ring 1/8 turn to release element.
expansion tank. Continue the above procedures to work
(5) Clean element thoroughly in solvent and
air out of the system. If air in the system persists, check
suction lines for air leaks.
(6) Refer to paragraph 4-76 to refull steering
(4) Check the return line filter (fig. 2-8.1) after
the system has been purged and operated for about 15
c. Suction Screens, Hull Numbers 8520 thru 8660
minutes. Replace the filter element if necessary.
and 8580 thru 8618.
(1) These screens (2) are located in the
(5) Clean suction strainer (in storage tank) after
12gallon steering system storage tank in the engine
the first 25 hours of operation. Pieces of metal or other
room. It is necessary to remove the top cover of the
foreign matter should be investigated to determine their
storage tank for access to the screens. See figure 4-62.
(2) Drain oil and clean the screens every 200
c. Filling Steering System, Hull Numbers 8520 thru
(3) Refer to paragraph 4-76 to refill the steering
8560 and 8580 thru 8618.
(1) Filling procedures for the steering system on
4-78. Steering System Pumps
hulls 8520 thru 8560 and 8580 thru 8618 are similar to
a. General. Steering
the procedures described in paragraph b for hulls 8500
mounted aft on the outboard engine of each propulsion
thru 8519 craft. Hulls 8520 thru 8560 and 8580 thru 8618
unit. Pumps mounted on the starboard propulsion unit
do not have an expansion tank in the pilot house. Filling
are left-hand rotating as viewed from the shaft end of the
is done in the 12-gallon tank in the engine room. Check
pump. Pumps for the port propulsion unit are right-hand
level in the sight glass as the system is being filled.
rotating. The pump made for the left-hand rotation is
identified by an "L" in the model code.
(2) Hulls 8520 thru 8539 do not have ball
valves in the pump discharge lines. The output from both
steering pumps is used normally. If one pump should fail
Pumps must be driven in the direction of the
or is not running, the check valve will prevent fluid from
arrows cast on the pump ring. If it is desired to
reversing through the pump.
change the direction of drive rotation, it is
necessary to reverse the ring.
(1) Close suction line valve at tank (hull
numbers 8500 thru 8519).