Piper Dakota Maintenance Manual page 376

CHART 3701. TROUBLESHOOTING (VACUUM SYSTEM) (contd)
TROUBLE
Normal pressure indication
but sluggish operation of
instruments.
High system pressure.
Regulator cannot be ad-
justed to produce correct
pressure.
Vacuum correct on ground
but will not maintain pres-
sure at altitude.
Vacuum correct but pilot
reports pressure erratic or
shows complete loss in
flight.
Pressure can only be main-
tained at full throttle on
ground.
PIPER AIRCRAFT
PA-28-236
MAINTENANCE MANUAL
CAUSE
Faulty instrument.
Incorrectly adjusted
vacuum regulator.
Sticking vacuum regulator
or dirty screen.
Leaking lines.
Malfunctioning
vacuum pump.
Vacuum pump mal-
unctioning.
Sticky regulator.
Sticky regulator.
Oil in pump due to leaky
engine seal or cleaning fluid
blown into pump while
cleaning engine.
Leak in system.
Worn pump.
Stuck regulator.
2E4
REMEDY
Replace instrument.
Adjust regulator.
Clean and check operation
of regulator.
Check lines and fittings.
Replace pump.
Replace pump.
Clean regulator.
Clean regulator.
Replace pump.
Repair or replace lines.
Replace pump.
37 - 02 - 00
Page 37 - 02
Reissued: August 1, 1986