GMC 1976 ZEO 6083 Maintenance Manual page 338

1 . Raise vehicle.
FAN AND FAN CLUTCH
REMOVAL
2. Remove shroud to venturi ring seal retainer
strap.
3. Fold venturi ring to shroud seal forward and
over shroud .
4. Remove the four (4) nuts attaching fan clutch
to water pump hub (See figure 6) .
5 . With assembly in the shroud area and removed
from the hub, remove the four (4) attaching bolts
that secures fan clutch .
6. Remove fan and fan clutch after they are sepa-
rated.
WARNING : IF A FAN BLADE IS BENT OR DA-
MAGED IN ANYWAY, NO ATTEMPT SHOULD
BE MADE TO REPAIR AND REUSE THE DA-
MAGED PART. A BENT OR DAMAGED FAN AS-
SEMBLY SHOULD ALWAYS BE REPLACED
WITH A NEW FAN ASSEMBLY . I T IS ESSENTIAL
THAT FAN ASSEMBLIES REMAIN IN PROPER
BALANCE AND PROPER BALANCE CANNOT
BE ASSURED ONCE A FAN ASSEMBLY HAS
BEEN BENT OR DAMAGED . A FAN ASSEMBLY
THAT IS NOT IN PROPER BALANCE COULD
FAIL AND FLY APART DURING SUBSEQUENT
USE CREATING AN EXTREMELY DANGEROUS
CONDITION .
Figure 8-Thermostat Installation
INSTALLATION
1. Install fan and fan clutch separately into the
area in the shroud between the water pump and the
radiator . Be careful not to damage the radiator core .
2. Install four (4) attaching bolts that secure the
fan to the fan clutch and torque to 20 ft . lbs. (See
figure 6) .
3. Position the assembly over the water pump
hub studs and torque the attaching nuts to 20 ft. lbs.
4. Fold venturi ring to shroud seal back over the
venturi ring .
5. Install seal retainer strap.
6. Lower vehicle.
ENGINE COOLING 6K- 7
FAN CLUTCH
Automatic fan clutches, Figure 8, are hydraulic
devices used to vary the fan speed in relation to the
engine temperature . Automatic fan clutches permit
the use of a high delivery fan to insure adequate
cooling at reduced engine speeds while eliminating
overcooling, excessive noise, and power loss at high
speeds .