Replacing Thermostat - Chevrolet 10 1971 Series Chassis Service Manual

ENGINE COOLING 6K-4
Fig. 5— Replacing Thermostat
2. Disconnect heater hose, lower radiator hose and
by pass hose (as required) at water pump.
3. Loosen Delcotron and remove fan belt then remove
fan bolts, fan and pulley.
If a fan blade is bent or damaged in
CAUTION:
any way, no attempt should be made to repair
and reuse the damaged part. A bent or damaged
fan assembly should always be replaced with a
new fan assembly!
It is essential that fan assemblies remain in
proper balance and proper balance cannot be as­
sured once a fan assembly has been bent or
damaged. A fan assembly that is not in proper
balance could fail and fly apart during subse­
quent use creating an extremely dangerous
condition.
Thermostatic fan clutches must be kept
NOTE:
in an "in-car" position. When removed from
the car the assembly should be supported so
that the clutch disc remains in a vertical plane
to prevent silicone fluid leakage.
4. Remove pump to cylinder block bolts and remove
pump and old gasket from engine.
On in line
NOTE:
straight out of the block first, to avoid damage
to impeller.
Installation
1. Install pump assembly on cylinder block then, using
a new sealer coated pump-to-block gasket tighten
bolts securely.
2. Install pump pulley and fan on pump hub and tighten
bolts securely.
A guide stud (5/16"-24 x 1" bolt with
NOTE:
the head removed) installed in one hole of the
fan will aid in aligning hub, pulley and fan.
Remove stud after starting the remaining three
bolts.
3. Connect hoses and fill cooling system.
4. Install fan belt and adjust as previously outlined.
5. Start engine and check for leaks.
engines, pull the pump
10-30 CHEVROLET TRUCK SERVICE MANUAL