Piper Dakota - Troubleshooting (Vacuum System)

37 - 02 - 00
Page 37 - 01
Reissued: August 1, 1986
2E3
GENERAL
The instrumentation in this airplane gives a quick and accurate indication of airplane attitude,
performance, and condition. Maintenance, other than described, should be done by the instrument
manufacturer or an authorized repair station.
DESCRIPTION AND OPERATION
The vacuum system employed to operate the gyro instruments comprises an engine driven dry vacuum
pump, vacuum regulator and filter, and necessary tubing. A vacuum gauge is used to constantly monitor the
system. Senal numbers 28-8611001 and up have an auxiliary dry air pump system, providing a backup source
to operate gyro flight instruments if the engine driven pump fails. A vacuum gauge is used to monitor the
system and an annunciator is used to indicate a failing engine driven pump.
TROUBLESHOOTING
CHART 3701. TROUBLESHOOTING (VACUUM SYSTEM)
No vacuum indication Filter clogged or dirty. Clean or replace filter.
at gauge.
Line from gyro to filter re- Check line.
stricted.
No vacuum indication Faulty gauge; malfunc- Replace gauge. Replace
at gauge or source. tioning pump. pump.
Low vacuum system Filter dirty. Clean or replace filter.
pressure.
Vacuum regulator valve in- Adjust regulator valve in
correctly adjusted. accordance with adjust-
ments in this section.
Line from gyros to filter Repair or replace line.
restricted.
Line from pump to gyros Check all lines and fittings.
leaking.
TROUBLE CAUSE REMEDY
PIPER AIRCRAFT
PA-28-236
MAINTENANCE MANUAL