EFFECTIVITY:
040-999 32-40-00
32-40-00 Jan10/90
PIPERAIRCRAFT
PA-42-720(AdvancedTrainer)
MAINTENANCEMANUAL
A. WheelAssemblies (continued)
2. Removaland Disassembly of B.F. Goodrich3-1392Main Wheel (referto 32-40-00 Figure401)
(a)
Placeairplaneon jacks (referto7-10-00).
(b)
Putparkingbrakeonto hold the brake assemblydisc-carrierin position.
(c)
Removewire retaining ring, hub cap, cotterpin, and axlenut.
(d)
Removewheelfrom axle.
(e)
Releaseall air out of tire by depressingand removing valve.
(f)
Thetire bead mustbe broken from wheel flangeusinga mallet,bead breaker, pneumatictire dismounter,or other applicable,non-metallicinstrument.
CAUTION: DO NOT PRYBETWEENWHEELANDBEADWITHSHARPTOOLSWHICH COULDDAMAGEWHEELANDTIRE. DO NOT USEPOWEROR IMPACT WRENCHESTO REMOVE WHEELBOLTS OR NUTS.
(g)
Removeeight tie-bolts and washers fromwheel;separatethe halves.
(h)
If wheel halvepackingO-ring is to be reused,markpositionto reinstall as closely aspossible.
(i)
Toremovebearing cups, heat wheels (explainedin Repair of Main Wheel Assembly)and after
coolingcupsevenly,drive them out of theirwheelhalveswith a non-ferrous,softmetal,or non-metallicdriftpin. If possible, use an arbor press.
3. AssemblyandInstallationof B.F.Goodrich3-1392MainWheel(referto 32-40-00 Figure401)
NOTE: Wheninflatingtires on BFG wheels,allowassemblyto stand at least12 hours fortire andwheelto stabilize.
(a) Retreatingand Repainting.
(1.) Thoroughly cleanrepairedsurfaces and areasof the wheelwherepaint has been removed. (2.) Treat cleanedsurfaceswith Dow No. 1 solution (MIL-M-3171).Paintwith one coat of zinc chromateprimer(specificationTT-P-1757)and one coatof aluminum polyurethanepaint.
NOTE:Never paint workingsurfacesofbearing cups. Thewheelregistersurfacesand bolt bosses mustreceiveonlyone mist coat of zinc chromateprimer.
(b)
Placethe inner wheel half on a clean flat surface. Withthe mating flange up, place the packingO-ringontoits register, positioningitas close aspossibleto its originalpositionifthe O-ring is reused.
(c)
Installtire and outer wheel half respectively on the inner wheel half. Be sure to properly alignthe male and female registers,whereapplicable.
(d)
Installwashersand connecting bolts.Staggertorque them 190 -210inch-pounds. (Lubetorque)
NOTE:Aftertorquingis completed, retorqueboltsa second time, ensuring propertorqueis achieved.Compressionof the packingO-ringcausesthe initial reading to be false.
EFFECTIVITY:
PAGE 040-999
2 Jan 10/9032-40-00
PIPER AIRCRAFT
PA-42-720 (Advanced Trainer)
MAINTENANCE MANUAL
A. Wheel Assemblies (continued)
PackingRing
NOTE: Ateach tire change,Visually inspect wheel halvesfor corrosion, especiallynotingbead seat area(tirecontactsurface)and tire tieboltholes. Remove corrosion with400grit emery cloth and touch up with DowNo.19solutionor equivalent, Primealltreatedareaswith one coatof uerethaneprimer.Bare magnesium is silver in color.Theprotectivefinishput on wheelhalves
at the factoryis gold in color. (Dow No. 7 or IriditeNo. 15). If corrosion cannotbe removed bysandingdownto bare metal within limits specifiedin32-40-00Figure402, take wheel half out of service
Screw Lockwire(MS2099C32)
View A
Inner Wheel Half Torque Key
View B
Apply MIL-T-5544 CompoundTo These Surfaces
B. F. Goodrich 3-3192MainWheelInstallation Figure 401
EFFECTIVITY:
040-999
32-40-00
32-40-00 Jan10/90
PIPER AIRCRAFT
PA-42-720 (Advanced Trainer)
MAINTENANCE MANUAL
A. WheelAssemblies(continued)
3. AssemblyandInstallationof B.F. Goodrich 3-1392 Main Wheel (refer to 32-40-00 Figure 401)
(continued)
(e)
If the air valve is removed,installand torque to 35 -65 inch-pounds.
(f)
With the valve core removed, inflate tire enough to seat the tire beads against the wheel flanges.
(g)
Install the valve core and inflate tire to 110 psi. If tire is new, proceed to step (h). If tire is used, proceed to step (i).
(h)
Let inflated tire stand for 12 to 24 hours and check for normal 10% pressure loss. Reinflate tire, brush water or soap solution over exterior of tire, and inspect for leaks.
NOTE: Bubble formation around sidewall vents on tire is normal during water or soap solution test.
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