Dodge 2000 DURANGO Service Manual page 226

7 - 24 COOLING SYSTEM
SERVICE PROCEDURES (Continued)
(3) Place a drain pan under the thermostat hous-
ing, then remove the thermostat housing and ther-
mostat (4.7L only).
(4) Remove cylinder block drain plugs. Refer to
(Fig. 26) (Fig. 27).
Fig. 26 Cylinder Block Drain Plug—5.2L/5.9L
Engines—Typical
1 – BLOCK DRAIN PLUG
Fig. 27 Cylinder Block Drain Plug—4.7L Engine—
1 – CYLINDER BLOCK DRAIN PLUG
2 – EXHAUST MANIFOLD AND HEAT SHIELD
REFILLING
Clean cooling system prior to refilling. Refer to
Cooling System Cleaning section of this group.
(1) Install cylinder block drain plug(s) s. Coat the
threads with Mopar Thread Sealant with Teflon.
Typical
(2) Close radiator petcock.
(3) Fill cooling system with a 50/50 mixture of
water and Mopar Antifreeze/Coolant.
(4) Fill coolant reserve/overflow tank to FULL
mark on indicator stick.
(5) Start and operate engine until thermostat
opens (upper radiator hose warm to touch).
(6) If necessary, add a 50/50 water and Mopar
Antifreeze/Coolant mixture to the coolant reserve/
overflow tank. This is done to maintain coolant level
between the FULL and ADD marks. The level in the
reserve/overflow tank may drop below the ADD mark
after three or four warm-up and cool-down cycles.
COOLING SYSTEM—CLEANING/REVERSE
FLUSHING
CLEANING
Drain cooling system and refill with water. Run
engine with radiator cap installed until upper radia-
tor hose is hot. Stop engine and drain water from
system. If water is dirty, fill system with water, run
engine and drain system. Repeat until water drains
clean.
REVERSE FLUSHING
Reverse flushing of cooling system is the forcing of
water through the cooling system. This is done using
air pressure in the opposite direction of normal cool-
ant flow. It is usually only necessary with very dirty
systems with evidence of partial plugging.
REVERSE FLUSHING RADIATOR
Disconnect radiator hoses from radiator inlet and
outlet. Attach a section of radiator hose to radiator
bottom outlet fitting and insert flushing gun. Con-
nect a water supply hose and air supply hose to
flushing gun.
CAUTION: Internal radiator
exceed 138 kPa (20 psi) as damage to radiator may
result.
Allow radiator to fill with water. When radiator is
filled, apply air in short blasts. Allow radiator to
refill between blasts. Continue this reverse flushing
until clean water flows out through rear of radiator
cooling tube passages. Have radiator cleaned more
extensively by a radiator repair shop.
REVERSE FLUSHING ENGINE
Drain cooling system. Remove thermostat housing
and thermostat. Install thermostat housing. Discon-
nect radiator upper hose from radiator and attach
flushing gun to hose. Disconnect radiator lower hose
DN
pressure must not