GMC 1976 ZEO 6083 Maintenance Manual page 336

Figure 5-Radiator Drain Plug
4. Run engine, drain and refill the system, as
described in Steps 1, 2 and 3, a sufficient number of
times until the drained liquid is nearly colorless.
5. Allow system to drain completely and install
block drain plugs, if removed.
REMOVAL
1 . Drain radiator . Disconnect bypass and remoV
heater hose from water pump . Loosen all belts.
WATER PUMP
2. Raise Motor Home . Disconnect lower radiator`
hose from water pump .
3. Remove venturi ring seal strap.
4_
4. Fold venturi ring to shroud seal forward and V
over shroud .
5. Remove four (4) nuts attaching fan clutch to `-j
water pump hub. See Figure 6. Position fan and fan
clutch assembly forward in the shroud . Be careful
not to allow the assembly to damage the radiator
core .
6. Remove the venturi ring.
7. Remove water pump pulley .
8. Disconnect the power steering pump and L .H~
upper venturi ring bracket.
ENGINE COOLING
6K- 5
6. Fill radiator to filler neck with coolant meeting
GM Specification 1899-M (for ease and speed of
filling use a 20-inch length of rubber hose and funnel
to add coolant at radiator cap), to provide the re-
quired freezing and corrosion protection (at least a
50 percent solution for -34°F (-36°C). Install radiator
cap. Make certain arrow on cap lines up with over-
flow tube . See Figure 5.
7. Fill reservoir to "COLD" level mark . See Fig-
ure 2.
8 . Add anti-foam GM-1050531 to vehicles
equipped with automotive air conditioning . Run en-
gine with heater controls in "HEATER" and
"HOT" position until normal operating temperature
is reached.
9. Check and adjust coolant to proper level. In-
stall coolant reservoir cap.
CAUTION: Vehicles equipped with water
heater pre-heat must have coolant checked
at reservoir and coolant added as necessary
after checking several times. The additional
heater hose used for the pre-heat requires a
longer period to normalize the cooling sys-
tem.
9. Remove water pump attaching bolts. Remove '
water pump .
10 . Clean engine block of old gasket at sealing
Y
surfaces .
Figure 6-Radiator Cap