Prestolite Hydraulic Pump Test And Adjustment - Piper PA-44-180 SEMINOLE Maintenance Manual

ASSEMBLY OF PRESTOLITE HYDRAULIC PUMP (Refer to Figure 29-3.) (cont.)
G. Check freedom of rotation and end play (thrust) of the armature within the assembly. A minimum
of 0.005 inch end play is permissible. Adjust to this tolerance if necessary by adding or removing
thrust washers on drive end of armature shaft.
2. Assemble valve and gear case to the reservoir as follows:
A. If removed, place pump gears in valve and gear case and install cover. Install cover attaching
bolts and secure.
B. Lubricate reservoir seal ring with hydraulic fluid (MlL-H-5606A) and place in recess provided in
case.
C. Position reservoir on valve and gear case. Care should be taken when aligning the armature shaft
with the pump gear. Do not run the motor to accomplish this.
D. Ensure the seal ring is properly positioned, then install attaching screws. Tighten one screw to
hold the assembly together. Connect motor to a 14 volt power supply. With an ammeter in the cir-
cuit, tighten the rest of the screws such that the current drawn does not exceed 12 amperes.
3. Attach the pump base to the pump as follows:
A. With pump inverted, lubricate O-ring seals and install them in recesses provided in the valve and
gear case.
B. Install attaching bolts with washers and torque to 70 inch-pounds.
C. Safety attaching bolts with MS20995-C32 wire.
4. Conduct motor operational check not to exceed 10 seconds running time.
TEST AND ADJUSTMENT OF PRESTOLITE HYDRAULIC PUMP (Refer to Figure 29-4.)
1. Test Equipment:
A. Hydraulic pump and mounting base.
B. Pressure gauge (0 - 1000 psi).
C. Pressure gauge (0 - 3000 psi).
D. Hoses with fittings to connect base and gauges.
E. Power supply (14 Vdc).
F. Ammeter (0 to 100 amps).
G. Fuse or circuit protector (100 amps).
2. Test and Adjustment:
Use Test gauges of known accuracy when performing the
f o llowing tests.
A. Connect the 0 to 1000 psi gauge to the low pressure port of the pump base.
B. Connect the 0 to 3000 psi gauge to the high pressure port of the pump base.
C. Connect black lead of pump motor to the negative terminal of the DC power supply.
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.
D. Remove the filler plug located on the forward side of the pump. Loosen vent screw and add fluid,
MIL-H-5606, through the filler hole until full. Reinstall the filler plug and tighten the vent screw.
E. 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.
PIPER AIRCRAFT
PA - 4 4 - 1 8 0 / 1 8 0 T
AIRPLANE MAINTENANCE MANUAL
— NOTE —
NOTE
2C10
29-11-05
Page 29-15
Revised: June 20, 1995