Not be operated until freon and oil have been added
Be operated for a period of time to reach a stable condition and then the freon level rechecked
Be operated and pressure check performed
Breakage usually occurs where the cables are swaged to turnbuckle and ball terminals
Breakage usually occurs where cable pass over pulleys and through fairleads
Breakage sites are unpredictable and usually occur randomly anywhere along the length of a cable
Vacuum pump
Distributor valve
Shuttle- valve
Vacuum relief valve spring weak
Vacuum relief valve improperly adjusted
Vacuum pump over speed
Hand pump inport check valve
Inport/outport orifice check valve
Hand pump outport check valve
That air is entering the pump
That the main system relief valve is sticking open
Of low accumulator preload
The altimeter will read low and the airspeed indicator will read high
The altimeter and airspeed indicator will both read high
The altimeter and airspeed indicator will both read low
Composite inspection
Sheet metal inspection
Both composite and sheet metal inspection
Too low or nor preload in the accumulator
Too much preload in the accumulator
Air in the fluid
Short in the up limit switch
Short in the down limit switch
Short in the gear safety switch
Pulley misalignment
Cable misalignment
Excessive cable tension
If the air to each vacuum instrument is connected to a common atmospheric pressure manifold, the system generally will be equipped with instrument filters only
Vacuum systems are generally more effective at high altitudes than positive pressure systems
Dry- type vacuum pump with carbon vanes are susceptible to damage form solid airborne particles particles and must take in only filtered air
Low fluid
Low air charge
A restricted metering pin orifice
Upward, regardless of elevator position
Downward, regardless of elevator positon
Downward if the elevator is in the UP position and upward if the elevator is in the down position