Jan 10/9030-60-00
PIPERAIRCRAFT
PA-42-720(AdvancedTrainer)
MAINTENANCEMANUAL
B. MaintenancePractices(continued)
9. Brush Module Replacement(continued)
(b) Removeassemblyscrewsand separate modulesand spacers.
NOTE:The part numberof each moduleis etched into the surface ofthe plastic housing. Replacewith the same part numbermodule.
(c)
Restackmodulesandspacersasshown in Figure 512. If there is interference between adjacentringterminals,reorient center moduleas shown in Figure 511.
NOTE: Ensure that flat washeris positioned betweenstar washer and housing.
(d)
Reconnectaircraftwire harness andensureadjacentring terminals are not touching.
(e)
Installassemblyon the aircraft and check alignment.
1.
BrushModuleAssembly
2.
NylonSpacer 3E2011-28-4Only
3.
Wire Marker NOTE:
A. -1 & -4 Assembly The Alternate StackingArrangement
B. -2Assembly Is Used WhenThereIs Interference
C.-3Assembly BetweenAdjacentModule Ring Terminals.
BrushModuleAssembly(3E2011) AlternateModuleStackingArrangement
Figure510 Figure511
4. Spacer 1. Brush Module
Assembly
3E2011-1
2. BrushModule P/N 3E2044 Assembly
3E2011-2
3. Brush Module 7.Lockwasher Assembly
6. Washer 3E2011-3
8. Nut
5.Screw
ModuleBrushAssembly(3E2044-1)
Figure 512
EFFECTIVITY:
030-60-00 JanJan 10/9010/90
PIPERAIRCRAFT
PA-42-720 (Advanced Trainer)
MAINTENANCEMANUAL
B. MaintenancePractices (continued)
10. Slip Rings
(a) Machining of the Slip Rings
Slip rings, with roughened or damaged surfaces, can be machined for prolonged service life as
follows:
(1.) Remove slipring assembly frompropeller hub.
(2.) Mount assembly in lathe not exceeding 0.002 inch run-out over 360° rotation, with respect
to mounting surfaceof assembly. (3.) Make light cut to remove surfacedamage. (4.) Ensure contact surfaces of three slip rings are parallel and flat to within 0.002 inch overall
of each other. (Deviation from flat cannot exceed 0.002 inch over four inch arc.) (5.) If necessary, undercutinsulationbetween slip rings 0.02 to 0.03 inch below contact surfaceof slip rings. (6.) Ensure minimum distance for refacing slip ring assemblies is not less than 1.160 inch betweencopper surfaces and legs of assembly.
NOTE: If solder or braze connectionon underside of slip ring is exposed while machining,replace slip ring assembly.
(b)Replacementof Slip Rings
Replace slip ring assemblies that are open or shorted electrically, crackedor damaged structurally,or which have surfaces damaged beyond minor repair.
11.Deicer Boots
(a)
ResistanceCheck of Deicer Boots
To check for incorrect resistance, short or break circuit at brush-to-slip ring contact, disconnect harness at each timer and use an ohmmeter to read resistance from each deicer circuit lead (pins A, B, and C of harness plug or modular brush block) to ground.
(b)
Replacementof Deicer Boots
If test shows deicer boots have an open circuit, incorrect resistance,or are visible damaged beyond repair, replace deicer boot.
EFFECTIVITY:
040-999
Jan 1090 30-60-00
PIPER AIRCRAFT
PA-42-720 (Advanced Trainer)
MAINTENANCE MANUAL
B. Maintenance Practices (continued)
11. Deicer Boots (continued)
(c) Repairof Propeller Deicer LeadStrap (Figure801)
For repairs, use B. F. Goodrich Field Repair Kit No. 77-802, which contains rubberpatch
materialfor severalrepairjobs. Cements andsolventsspecifiedin directions are not included
in kit.
(1.) Clean repairareawith MEK or acetone to remove all grease and dirt. After last wipe with
cleaner,quicklywipe surface withclean,dry,lint-freecloth, remove solventfilm.
(2.) Apply one even coat of EC1300L or EC1403 cement (MinnesotaMiningand Mfg. Co.) to repair area. Allowto dry approximately 1 hour above 40°F. Apply secondevencoat of cement and allow to dry.
(3.) Cut patch(0.020inchthick rubber about 1/4inchlargeron all sides of repair area). Ensureprotectivepaper is on cemented side and applymaskingtape on open sideto preventpatch from curlingas cement dries. Stripoff protective paperand apply EC1300L and EC1403cementin smooth, evencoat;allowto air dry. After 1 hour, applysecond coatand allow to air dry.
(4.) With cement surfacesdry or slightly tacky,applylightcoat of MEK or Toluol over surfaces and quickly completecementingas specified. Allow 1 hour to air dry before peeling off maskingtape or mylar coatingon air side. Rub edges and centerof patch to ensure proper adhesion. (Approximately24 hours.)
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