GMC 1990 Light Truck Repair Manual page 481

47. W ater Pump Bypass Hose
50. Therm ostat Housing
54. W ater O utlet
171. W ater Pump
Figure 11—Thermostat Housing and Water Pump
Installed
• Remove the heat stove (191).
2. PCV hose.
3. Bolts (35), nuts (30), washers (29) and clamps (34).
4. Intake manifold (31) and exhaust manifold (37) as an
assembly.
5. Gasket (27).
THERMOSTAT HOUSING
REMOVAL
Remove or Disconnect (Figures 4 and 11)
1. Bolts (51).
2. Thermostat housing (50).
3. Gasket (49).
WATER PUMP REMOVAL
Remove or Disconnect (Figures 5 and 11)
1. Bolts (170).
2. Water pump (171).
3. Gasket (169).
22
mm (7/®" )
A.
B. 55 mm (
C. 40 mm (
10
D. mm (
25 mm (
H oles for Pushrods
E. 22 mm (
25 mm (1" )deep
Holes for Valve
Lifters
F. 50 mm x 155 mm
(2" x6" ) Lum ber
G. 50 mm (2" ) pegs for
Rocker Arm s
and Balls
B-05061
Figure 12—Valve Train Component Rack
COMPONENT REMOVAL
+ + Remove or Disconnect (Figures 3, 4, 12, 13,
and 14)
Tools Required:
J-3049 Valve Lifter Remover (Plier Type)
J-9290-01 Valve Lifter Remover
(Slide Hammer Type)
4.8 LITER L6 6A4-9
2
-1/8" )
1 2
-V ")
3
/s" )drill
1
" )deep
7
/s" ) d rill
VALVE TRAIN
F-04942