Pneumatic Deicer System Troubleshooting Chart With Deicer Boots Installed - Piper Navajo Chieftain PA-31-350 Service Manual

Troublel
Deicers do not inflate. Both
engines operating at minimum
cruise RPM or either engine at
2200 RPM.
NAVAJO CHIEFTAIN SERVICE MANUAL
e. Apply one brush coat of A-56-B cement to deicer and allow to dry at least one hour. Then apply sec-
ond coat and allow to dry at least four hours before operating deicers. Plane may be flown as soon as cement is
dry. Check flow strips for security. If not satisfactory, recement per instructions in Kit 760 322.
NOTE
If A-56-B cement has aged 3 months or over, it may be necessary
to dilute the cement with isopropyl acetate to obtain proper
brushing consistency. Mix thoroughly, approximately 5 parts
cement to one part isopropyl acetate.
TABLE XIV-VIII. PNEUMATIC DEICER SYSTEM TROUBLESHOOTING CHART WITH
DEICER BOOTS INSTALLED
Cause
Open circuit breaker.
System connection loose or
wire broken.
Timer not functioning.
Control valves not
functioning.
Piping lines blocked or
not connected.
Remedy
Push circuit breaker to reset.
Tighten or repair as required.
Test or replace as required.
Make electrical test. Replace
as required.
Blow out lines and inspect
connections. Make air leakage
test.
Deicers inflate slowly.
(Inflation time - 6 seconds.)
Piping lines partially
blocked or not connected
securely.
Deicer pump valve not
functioning.
Low air pump capacity.
Deicer puncture.
Deicers inflate, indicator light
does not function. (Ascertain
that deicer boot switch is ON.)
Indicator lamp burned out.
System pressure not being
reached.
Pressure switch not functioning.
Wires loose or broken.
Poor grounding of pressure
switch.
Blow out lines and inspect
connections. Make air leakage
test.
Check fitting in deicer port for
proper installation.
Check performance to
manufacturers specifications.
Repair per specification or
replace.
Replace lamp.
Check "deicers inflate slowly"
above.
Make electrical test and replace
if required.
Make electrical test. Repair or
replace broken wires. Check
for proper ground.
Readjust pressure control valve.
Inspect and blow out lines.
Inspect and clean.
Deicers deflate slowly.
Pressure control valve set too low.
Piping or lines partially blocked.
Control valve partially blocked.
Revised: 3/31/94
ACCESSORIES AND UTILITIES
4G12