Page 32.22 Chapter 32 Landing Gear R66 Maintenance Manual SEP 2012
32-64 System Maintenance
A. Leak Check
WARNING
D679 Cylinder contents are under extreme pressure. Install
MT545-1 pin assembly in D757-1 valve assembly during
maintenance to prevent cylinder discharge.
1. Disconnect D674-1 line assembly from presssure cylinder valve. Install protective
cap on cylinder valve fitting. Cover D674-1 line fitting to prevent contamination, but
do not install an air-tight seal (D674-1 line fitting must be allowed to leak to verify
check valve function at each float chamber).
2. Unfasten hook-and-loop fasteners along inboard sections of float cover to expose
lacing. Loosen, but do not remove, lacing.
3. Unfasten outboard sections of float cover and unroll float to expose valves.
4. Inflate floats with filtered, oil-free, dry air to 2.0 psig via topping valves.
5. Allow float air temperature to stabilize for 5 minutes minimum then record OAT and
pressure in each float chamber.
6. One to two hours after initial pressure check, again record OAT and pressure in each
float chamber. Allowable chamber pressure drop from initial measurement is 0.2
psig adjusted for any temperature change. Pressure will change by 0.06 psig per
degree C temperature change. For example, float chamber pressure will decrease
0.6 psig if temperature drops 10 degrees C.
7. If leaks are detected, repair float with supplied repair kit and repeat steps 4, 5, & 6.
8. Connect D674-1 line assembly to cylinder valve and torque per Section 20-33.
9. Pack float per Section 32-63 Part C.
NOTE
Annually apply A257-7 dry-film lubricant (see Section 20-78) to
float cover snap mating surfaces.
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