Service and Repair Manual

AN 01-25CN-2

PARAGRAPH 6

  2. The hydraulic lines for operating the landing gear are accessible for servicing through the wheel compartment or the fuel tank compartment. Removable plates are provided where lines pass through the wing surface.

  3. The lines for operating the flap cylinder are accessible through the lower surface doors near the inboard end of the flaps, or the hand holes immediately forward of these doors.

  (b) MOTOR DRIVEN HYDRAULIC PUMP.

  1. The electric pump assembly is the Eclipse aviation pump and motor assembly, type 809, model 1. The pump is equipped with an integral relief (by-pass) valve adjusted to 1150 psi.

  2. CONSTRUCTION.-The hydraulic electric pump consists of a spur gear type pump mounted on a 24-volt electric driving motor. The motor armature shaft is connected to the upper gear shaft of the pump unit by a flexible coupling. The pump head in. corporates an inlet and an outlet -port for external pipe line connections. The pressure relief valve is also assembled on the pump head and provides a means of limiting the outlet pressure at 1150 psi. An oil seal, installed on the drive end of the upper spur gear shaft, prevents leakage of oil into the electric motor housing from the pump housing. The spur gear mechanism consists of two gears.on shafts. 'Me upper gear shaft incorporates a flexible coupling which is keyed to the armature shaft and provides the driving force for the pump. The lower gear is meshed with the upper gear and its shaft is retained in the two pump housing sections. The pump housing is the split type held together by 8 bolts and two cap screws. The two pump housing sections are held in alignment by two staked pins through the pump flanges.

  3. INSTALLATION.

    a. The nut is mounted, by means of a bracket provided on the motor housing, just forward of the battery installation to minimize the weight of cable and to reduce voltage drops in the wires. A type B-6B switch, located on the control stick below the grip, controls the operation of the pump.

    b. Connect the inlet port of the pump to the hydraulic supply tank.

    c. Connect the outlet port of the pump to the system supply line.

4. SERVICE AND REPAIRS.-If the electric motor fails to,operate or operates at too low a speed, the possible cause may be low voltage, due to a discharged battery. Check the battery and recharge if necessary. It may also be due to loose or corroded battery terminals. Clean, tighten, and coat with vaseline. If these are not the cause, check the wiring connections for loose or high-resistance connections. Check brushes for binding, worn brushes not properly seated, and excessive brush side play. Check for a dirty commutator, rough or pitted commutator, shorted, grounded, or open motor armature, grounded or open motor field coils, or a defective switch. If the motor shows low output pressure or capacity, check the system for insufficient fluid supply, low setting of the relief valve, leak in the line or valves, low operating speed, loose fittings, or improper fluid. For erratic output or pressure, check for air in the pump lines. If the pump overheats, check for worn or binding parts or sustained operation at high preasure.

5. DISASSEMBLY. - To disassemble the electric motor-driven hydraulic pump, disconnect the electric conduit from the battery, and the inlet and outlet hydraulic lines from the ports on the pump face. Remove the bolts attaching the electric motor bracket to the fuselage shelf and remove the assembly from the fuselage. Place the pump assembly in a vise so that the electric motor mounting bracket is- engaged between the jaws of the vise. Cut the lock wire on the two cap screws and remove' the screws. Engage the heads of the eight through bolts with a wrench and turn the lock nuts off the inboard side of the pump flange with another wrench. Release the assembly from the vise and turn it so that the pump housing is horizontal, Drive the two staked pins from the pump flanges with a punch and light hammer. The port face of the pump can now be separated from the pump body by lightly tapping around the port face with a wooden hammer. After the port face has been removed, the spur gears can be pulled from the pump housing. Extreme care should be exercised in the handling of the spur gears that they do not become scratched or nicked. When overhauling more than one pump at a time, it is ad. visible to keep the spur gears in sets so that they may be reinstalled as on the original installation. The pump body can now be separated from the motor housing by removing the four lock nuts around the pump body flange. After the pump body is removed from the electric motor, the oil seat may be removed for inspection or replacement by unscrewing the slotted nut in the pump body. Disassembly of the relief valve on the port face of the pump simply requires the removal of the cap and the unscrewing of the relief spring retainer.