Piper Cherokee LANCE, Service Manual

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PIPER CHEROKEE SIX / LANCE SERVICE MANUAL
07/15/06 VA - HYDRAULIC SYSTEM
1J7
5A-9. TEST AND ADJUSTMENT OF HYDRAULIC PUMP. (Refer to Figure 5A-4.)
a. Test Equipment:
1. Hydraulic pump and mounting base.
2. Pressure gauge (0-1000 psi).
3. Pressure gauge (0-3000 psi).
4. Hoses with fittings to connect base and gauges.
5. Power supply (14 VDC).
6. Ammeter (O to 100 amps).
7. Fuse or circuit protector (100 amps).
b. Test and Adjustment:
NOTE: Test gauges or gauges of known accuracy should be used when performing the following
tests.
1. Connect the 0 to 1000 psi gauge to the low pressure port of the pump base.
2. Connect the 0 to 3000 psi gauge to the high pressure port of the pump base.
3. Connect black lead of pump motor to the negative terminal of this DC power supply.
4. Remove the filler plug located on the forward side of the pump and ascertain that fluid is
visible up to the bottom of the filler plug hole. Should fluid be below the hole, add fluid, MIL-
H-5606A, through the filler hole until full. Reinstall the filler plug and tighten.
NOTE: A small vent hole is located under the vent screw head. Retain 1/64 inch clearance
between the screw head and the small vent hole.
5. Bleed air from the attached lines. (Lines may be bled by alternately connecting blue lead and
green lead to the positive terminal of the power supply until all air is exhausted.)
6. Connect blue lead to positive terminal of power supply. Pump should operate and the high
pressure gauge should indicate a specific pressure, as given in Table VA-I. (Should the gauge
indicate a pressure below or over the given pressure, adjust valve “A,” Figure 5A-3 accordingly
to obtain the desired reading.)
NOTE: When increasing pressure, the pump running time must not exceed 12 seconds. There
should be no external leakage while performing Steps 5 thru 8.
7. Disconnect blue lead. The high pressure reading should not drop more than 300 psi in five
minutes. High pressure may not be selected again for five minutes.
8. Connect green lead to positive terminal of power supply. Pump should operate in reverse,
dropping reading on high pressure gauge to zero. The low pressure gauge should indicate 500
to 800 psi. (Should the gauge indicate a pressure below 500 psi or over 800 psi, adjust valve
“B,” Figure 5A-3, accordingly to obtain desired reading.) Disconnect green lead. Both pressure
gauges should indicate zero psi.
9. Should it be necessary to check the pump motor, first connect the ammeter in the electrical
circuit with the positive terminal of the meter to the black lead and negative terminal of the
meter to the negative terminal of the DC power supply.