Prestolite Hydraulic Pump Installation - Piper PA-44-180 SEMINOLE Maintenance Manual

TEST AND ADJUSTMENT OF PRESTOLITE HYDRAULIC PUMP (Refer to Figure 29-4.) (cont.)
F. Connect blue lead to positive terminal of power supply. Pump should operate and the high pres-
sure, gauge should indicate between 2000 and 2500 psi. (Should the gauge indicate a pressure
below 2000 psi or over 2500 psi, adjust HIGH PRESURE valve, Figure 29-3 to obtain the desired
reading.)
When increasing pressure, the pump running time must not
exceed 12 seconds. There should be no external leakage while
performing steps E through H.
G. Disconnect blue lead. The high pressure reading should not drop more than 300 psi in five min-
utes. High pressure may not be selected again for five minutes.
H. Connect green lead to positive terminal of power supply. Pump should operate in reverse, drop-
ping 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 THERMAL
RELIEF valve, Figure 29-3 to obtain desired reading.) Disconnect green lead. Both pressure
gauges should indicate zero psi.
I. To check the pump motor, 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.
J. Connect the blue lead from the pump motor to the positive terminal of the power supply. With
high pressure indication within 2000 to 2500 psi range on the pressure gauge, the ammeter should
read 75 amperes maximum. Disconnect the blue lead.
K. Connect the green lead from the pump motor to the positive terminal of the power supply. With
low pressure indication within the 500 to 800 psi range, the ammeter should read between 15 to
35 amperes.
In the event any of the various tests do not perform satisfactori-
ly, the pump assembly should be replaced
L. Disconnect the green lead from the power supply and permit the pressure to drop before discon-
necting the hydraulic lines.
INSTALLATION OF PRESTOLITE HYDRAULIC PUMP (Refer to Figure 29-3)
1. Insert grommet in pump base mounting hole.
2. Insert bushing in grommet.
3. Place washer over bolt and insert bolt through grommet and bushing and pump base.
4. Place washer and bushing over bolt and secure to mounting shelf.
5. Connect hydraulic lines to pump.
6. Connect pump electrical leads.
7. Check fluid level in pump. Refer to Chapter 12 for filling instructions.
8. With airplane on jacks, operate pump to purge hydraulic system of air, and check for leaks. After
operation, recheck fluid level.
PIPER AIRCRAFT
PA - 4 4 - 1 8 0 / 1 8 0 T
AIRPLANE MAINTENANCE MANUAL
— NOTE —
— NOTE —
2C12
29-11-06
Page 29-17
Revised: June 20, 1995