Jeep 1996 Grand Cherokee Service Manual - page 200
WARNING:
CONSTANT TENSION HOSE CLAMPS
ARE USED ON MOST COOLING SYSTEM HOSES.
WHEN REMOVING OR INSTALLING, USE ONLY
TOOLS DESIGNED FOR SERVICING THIS TYPE OF
CLAMP, SUCH AS SPECIAL CLAMP TOOL (NUMBER
6094) (Fig. 10). SNAP-ON CLAMP TOOL (NUMBER
HPC-20) MAY BE USED FOR LARGER CLAMPS.
ALWAYS WEAR SAFETY GLASSES WHEN SERVIC-
ING CONSTANT TENSION CLAMPS.
CAUTION:
A number or letter is stamped into the
tongue of constant tension clamps (Fig. 11). If
replacement is necessary, use only an original
equipment clamp with matching number or letter.
Inspect the hoses at regular intervals. Replace
hoses that are cracked, feel brittle when squeezed, or
swell excessively when the system is pressurized.
For all vehicles: In areas where specific routing
clamps are not provided, be sure that hoses are posi-
tioned with sufficient clearance. Check clearance
from exhaust manifolds and pipe, fan blades, drive
belts and sway bars. Improperly positioned hoses can
be damaged, resulting in coolant loss and engine
overheating.
Ordinary worm gear type hose clamps (when
equipped) can be removed with a straight screw-
driver or a hex socket. To prevent damage to
hoses or clamps, the hose clamps should be
tightened to 4 N·m (34 in. lbs.) torque. Do not
over tighten hose clamps.
When performing a hose inspection, inspect the
radiator lower hose for proper position and condition
of the internal spring.
VISCOUS FAN DRIVE
Also refer to the previous Cooling System Fan sec-
tion.
The thermal viscous fan drive (Fig. 12) (Fig. 13)is a
silicone-fluid-filled coupling used to connect the fan
blades to the water pump shaft. The coupling allows
the fan to be driven in a normal manner. This is
done at low engine speeds while limiting the top
speed of the fan to a predetermined maximum level
at higher engine speeds.
A thermostatic bimetallic spring coil is located on
the front face of the viscous fan drive unit (Fig. 12)
(Fig. 13). This spring coil reacts to the temperature
Fig. 9 Coolant Return Tube—5.2L V-8 Engine
Fig. 10 Hose Clamp Tool—Typical
Fig. 11 Clamp Number/Letter Location
ZJ
COOLING SYSTEM
7 - 7
DESCRIPTION AND OPERATION (Continued)