External Coolant Flow; Cooling System Flow: External Flow - Ford 6.4L Power Stroke Manual

Cooled exhaust
out to EGR valve
Heater
Core
Coolant Pump
Cooled coolant
to pump from
bottom radiator port

Cooling System Flow: External Flow

• Coolant is drawn into the inlet of the front cover from the bottom
radiator port and then flows from the coolant pump through the front
cover to the crankcase.
• Coolant is also routed from the front cover into the crankcase to a
passage that feeds the oil cooler (shown on next page).
• Coolant is routed from the front cover to the EGR coolers, EGR valve,
degas bottle, and the vehicle heater core.
• The horizontal EGR cooler receives coolant first, then the coolant
travels to the vertical EGR cooler through a short connection hose.
Hot coolant exits the vertical EGR cooler at the top and enters into
the front cover.
• A port next to the hot EGR return port in the front cover routes hot
coolant to the heater core for vehicle heating. The coolant then
travels to a Y-pipe where it meets with degas return coolant before
being sent into the front cover, just above the main coolant inlet from
the radiotor.
Co o li n g s y s te m

External Coolant Flow

Coolant feed
to EGR valve
Partially cooled
exhaust gases
Cooled Coolant
Radiator
17
Deaeration/coolant feed
to degas bottle
Color change indicates
coolant temperature
as heat is transfered
from exhaust gases
to the coolant
EGR Cooler #1
• The EGR valve receives its coolant from a passage at the top of
the vertical EGR cooler. Once the coolant exits the EGR valve it
is sent to the degas bottle (this passage is the highest point in
the system and is also the deaeration port).
• The port directly below the EGR valve return/deaeration port
on the degas bottle is used as a radiator fill/overflow line
connecting with the top of the radiator.
• A dual thermostat sytem is used to control the flow of return
coolant to the radiator. If the thermostats are open, coolant
flows to the radiator to be cooled. The bottom thermostat has
a bypass circuit that will allow coolant to return to the pump
when the thermostats are closed (speeding engine warm up).
Degas
Bottle
Hot exhaust
in from right
up-pipe
Radiator fill/
Overflow supply
to degas bottle
(flow in either direction)
Hot coolant
from pump to
top radiator port
26