10-24. AUXILIARY SYSTEM FUNCTIONAL CHECK - ENGINE RUNNING.
a. Start engine
b.Check to see that the "VAC OFF' light on the auxiliary pump switch is extinguished and the vacuum gage
registers at the proper level. If not, trouble shoot the pneumatic system.
c. Turn the auxiliary pump on.
d. Check the " AUX ON' light for illumination.
e. Check to see the "VAC OFF" light is still extinguished and that the vacuum gage still registers at the
proper level
f. Turn the auxiliary pump off.
g. Shut engine down.
10-25. MAINTENANCE AND SERVICE.
The auxiliary pump system should be inspected and functionally checked on a regular 100 hour/ annual basis.
The following should be checked
a. Mounting hardware
b. Solenoid and noise filter
c. Motor cradle.
d. Motor and pump assembly
e. Hoses, fitting and clamps.
f. Vacuum switches.
g. Wire and electrical connectors.
h. Elapsed time indicator (ETI) - under/behind instrument panel.
10-26. REMOVAL/REPLACEMENT — PUMP/MOTOR ASSEMBLY.
—Note—
The motor/pump assembly (P/N 4A3 -1) must be replaced at 500 hours
operating time as indicated on the elapsed time indicator (ETI) or at 10
years of installed time in the aircraft, whichever occurs first. The ETI
(P/N F7 - 97 - 1) is matched to the pump/motor assembly and must also
be removed and replaced at the same time.
a. Turn off aircraft master switch and auxiliary pump switch.
b. Disconnect hoses from the pump/motor assembly.
c. Disconnect electrical leads at terminals on pump/motor assembly. If a replacement assembly is not to be
installed immediately, insulate and secure the lead ends.
d. Loosen band clamps and remove pump/motor assembly from aircraft.
e. Remove fittings from pump/motor assembly. If serviceable, save fittings for use with replacement pump.
—Warning—
Do not place pump or motor housing in a vise. Hold by hand when
removing or tightening fittings.
f. Locate ETI under/behind instrument panel and disconnect electrical; leads. If a replacement ETI is not to
be installed immediately, insulate and secure the leads remaining in the aircraft.
g. Remove ETI. If attached with adhesive backing, pry loose or slice tape with a flat blade, being careful not
to scratch or cut any airframe components. Secure ETI to pump/motor assembly for later disposition.
PIPER AIRCRAFT
PA-28-161 CADET
AIRPLANE MAINTENANCE MANUAL
Issued: FEBRUARY. 28, 1989
I N S T R U M E N T
2B18