After exiting the oil pump, the pressurized oil
passes through a filter located on the aft right
side of the accessory gearbox. A filter by-
pass valve is provided as an alternate flow
path around the filter to allow uninterrupted
oil flow should the filter become obstructed.
If differential pressure on the inlet port and out-
let port of the filter exceeds a preset amount,
impending bypass is indicated and a switch
will close initiating a “L/R OIL FILTER” mes-
sage on the CAS (Figure 7-23).
An amber “L or R OIL FILTER” CAS message
will appear if oil filter bypass is impending
while on the ground. If oil filter bypass is im-
pending while in flight, the CAS message will
be white. An additional increase of approxi-
mately 5 PSID will cause the oil to actually by-
pass the filter. If it comes on inflight, moni-
tor oil pressure and temperature, while refer-
ring to the AFM.
After the oil passes through the filter (Figure
7-22), it is routed through three sections of
finned air-oil coolers located in the engine
bypass duct. A temperature control/bypass
valve will cause oil to flow through the finned
air-oil coolers when the oil is hot and bypass
the coolers when the oil is cold.
That portion of the oil that is dispensed to the
fan reduction gearbox (planetary gears), the
transfer gearbox, and to bearings #4 and #5 is
routed through the fuel heater/oil cooler
(FHOC) (Figure 7-22). This heat exchanger
provides for additional oil cooling and for
L E A R J E T 4 5
P I L O T T R A I N I N G M A N U A L
7-30
FOR TRAINING PURPOSES ONLY
FlightSafety
international
LEGEND
AIR/VENT
INLET OIL
SCAVENGE OIL
HIGH PRESSURE OIL
FUEL
SCREEN
CHECK VALVE
VENT TO
AMBIENT
ACCESSORY
GEARBOX
ACCESSORY
GEARBOX
NO. 4 AND NO. 5
BEARING CAVITY
NO. 4 AND NO. 5
BEARING CAVITY
TRANSFER
GEARBOX
TRANSFER
GEARBOX
FAN REDUCTION
GEARBOX
FAN REDUCTION
GEARBOX
NO. 6 BEARING
SUMP
NO. 6 BEARING
SUMP
TRANSFER
GEARBOX
VENT
BREATHER
PRESSURIZING
VALVE
ANTI-
SYPHON
ORFICE
OIL TANK
DRAIN PLUG
OIL LEVEL
SIGHT
PLUG
FILL
PORT
AUX FILL
PORT
OIL PUMP INLET
OIL PUMP
ELECTRICAL CHIP
DETECTOR AND
CHECK VALVE
FILTER
BYPASS
VALVE/SWITCH
FILTER ASSEMBLY
TEMP AND
PRESSURE
TEST PORT
MODULATOR
REGULATOR VALVE
ADJUST
FAN GEARBOX VENT
TEMP OR PRESSURE TEST PORT
ALTITUDE
OIL FLOW
REDUCTION
VALVE
AIR OIL
COOLER
(UPPER)
AIR OIL
COOLERS
(LOWER)
OIL TEMPERATURE SENSOR
T
P
OIL PRESSURE SENSOR
FUEL OUT
FUEL IN
OIL TEMP AND
PRESSURE
BYPASS VALVE
OIL TEMP OR
PRESSURE
TEST PORT
FUEL HEATER/
OIL COOLER
FUEL HEATER/
OIL COOLER
LR OIL FILTER
LR ENGINE CHIP
LR OIL PRESS LOW
LR FUEL HEATER
LR FUEL HEATER
Figure 7-22. Engine Oil System Schematic