GMC 4000 Series Service Manual page 548

M ounting Bolt
Radiator Core and Support
C O R E UPPER M O U N T IN G
4. Disconnect upper and lower coolant hoses
from radiator.
5. If vehicle is equipped with air conditioning
or power steering cooling coils, remove coils if
necessary.
6. Remove cotter key, nut, washer and lower
cushion from lower mount.
7. Remove upper mounting bolts and rubber
bushings.
8. To remove radiator and support assembly,
tilt assembly forward and lift assembly out of
vehicle.
9. To remove radiator core assembly from
support assembly, remove cap screws from fan
shroud and remove fan shroud. Remove cap screws
attaching radiator core assembly to support a s­
sembly and remove core assembly.
Installation
1. Position radiator core assembly in support
assem bly and secure with cap screw s.
2. Install fan shroud and retain with cap screws.
3. Carefully place radiator and support a s­
sembly in vehicle. Be sure components of lower
mount are properly positioned.
4. Assemble radiator upper mounts and com­
plete assembly of lower mounts.
5. Connect upper and lower coolant hoses to
radiator.
6. Install air conditioning or power steering
cooling coils (if removed).
7. Install electrical components on radiator
and connect throttle linkage to radiator support.
8. Fill cooling system and inspect system for
leaks.
PS-4500 MODELS (Fig. 3)
Removal
1. Support vehicle on blocks at a height suf­
ficient to allow lowering the radiator out of vehicle.
2. Drain radiator.
G M C S E R V I C E M A N U A L
Rubber Bushing
Nut
Control Island
Frame Bracket
Figure 2 — Radiator Upper and Lower M o untings ("L" M odels)
RADIATOR A N D SURGE TANK
Radiator
Support
Nut Cotter Pin
C O R E L O W E R M O U N T IN G
3. If necessary, remove grille and baffle to
gain access to radiator mounting bolts.
4. Disconnect radiator upper and lower hoses
at radiator.
5. Retain radiator safely in position and re­
move radiator mounting bolts. Carefully lower the
radiator out of vehicle.
Installation
1. Carefully insert radiator into position in
vehicle and retain with radiator mounting bolts.
2. Connect radiator upper and lower hoses.
3. Install grille and baffles (if removed).
4. Fill cooling system and check for leaks.
PRESSURE RELIEF VALVE
A N D FILLER CAP
Pressure relief valve assem bly, integral with
radiator filler cap, incorporates a pressure valve
Sec. 13
Page 537
W ashers
M o u n tin g
Bracket
T - 3 1 1 3