Troubleshooting Inspection Deice Boot Maintenance check deicer components and lines for cracks. If weather  cracking of rubber is noted, apply a coating of conductive  cement. The cement, in addition to sealing the boots against  weather, dissipates static electricity so that it does not  puncture the boots by arcing to the metal surfaces. Not all troubles that occur in a deicer system can be corrected  by adjusting system components. Some troubles must be  corrected by repair or replacement of system components or  by tightening loose connections. Several troubles common to  pneumatic deicing systems are shown in the left-hand column  of the chart in  Figure 15-33.  Note the probable causes and the  remedy of each trouble listed in the chart. In addition to using  troubleshooting charts, operational checks are sometimes  necessary to determine the possible cause of trouble. The life of the deicers can be greatly extended by storing  them when they are not needed and by observing these rules  when they are in service: During each preflight and scheduled inspection, check the  deicer boots for cuts, tears, deterioration, punctures, and  security; during periodic inspections, go a little further and  1.  Do not drag gasoline hoses over the deicers. 2.  Keep deicers free of gasoline, oil, grease, dirt, and  other deteriorating substances. 15-22 Figure 15-33.  Troubleshooting guide for wing deice system.  Boots do not inflate Slow boot inflation System will not cycle Slow deflation No vacuum for boot hold down Boots will not deflate during cycle Boots appear to inflate on aircraft climb • Open circuit breaker Faulty deflate valve Solenoid inoperable: 1. Improper voltage at solenoid 2. Blocked air vent in solenoid 3. Inoperative plunger Diaphragm not seated 1. Blocked vent orifice located in rivet bottom at  center of diaphragm 2. Dirty diaphragm seal area 3. Diaphragm ruptured • Two faulty deice control valves of faulty two-stage  regulators • Faulty check valve Relay not functioning • Leak in system boots • Lines blocked or disconnected Low air pump capacity • One or more deice control valves not functioning  properly • Deflate valve not fully closed • Ball check in deflate valve inoperative Leaks in system or boots • Pressure in system not reaching specified psi to  activate pressure switch • Leak in system or boots • Pressure switch on deflate valve inoperative • Low vacuum Faulty deflate valve (indicated by temporary reduction  in suction gauge reading) • Malfunctioning deflate valve or deice valve • Leak in system or boots • Faulty deflate valve • Vacuum source for boot holddown inoperative • Lines running through pressurized cabin loose or  disconnected • Reset circuit breaker Check deflate valves as follows: Solenoid inoperable: 1. Correct electrical system 2. Clean with alcohol or replace 3. Diaphragm not seated 1. Clean with .010 diameter wire and  alcohol 2. Clean with blunt instrument and  alcohol 3. Replace valve • Clean or replace valve assembly as noted  above • Replace check valve Check wiring or replace relay • Repair as needed • Check and replace lines Replace air pump • Clean or replace valve assembly as noted above • Clean or replace valve assembly as noted  above • Clean check valve or replace deflate valve Repair as needed • Clean or replace deice control valve as  noted above • Clean or replace deflate valve, as noted  above • Repair as needed, tighten all hose  connections • Replace switch • Repair as needed Clean or replace valve assembly as noted  above • Clean or replace valve assembly as noted  above • Repair as needed • Check and replace valve • Check operation of ball check in deflate  valve • Check for loose or disconnected vacuum lines and repair Problem Causes (most of which can be identified with a 343 Test Kit) Corrective action(s)