GMC 4000 Series Service Manual page 306

12. Fill cooling system and connect battery
cables.
13. Start engine and inspect for cooling system
and oil leaks.
TILT CAB MODELS WITH
TORO-FLOW DIESEL ENGINE
REMOVAL
1. Tilt the cab forward and drain cooling
system .
2. Disconnect cables from battery.
3. Disconnect equipment and wiring as neces­
sary to allow removal of control island.
4. Remove attaching bolts, then remove con­
trol island and cab rear support.
5. Disconnect exhaust pipes at exhaust mani­
folds.
6. Disconnect radiator hoses and heater hoses.
7. Disconnect all starter cables, ground straps
and other wiring connected to engine electrical
equipment.
8. Disconnect power steering lines (when used).
9. Disconnect engine oil cooler lines.
10. Disconnect fuel supply and return lines.
11. Disconnect propeller shaft and speedom­
eter drive at rear of transm ission.
12. Disconnect clutch release linkage. Also,
remove road draft tube and filter from rear of
engine.
13. Disconnect air discharge line and lubri­
cation lines from air com pressor. If vehicle is
equipped with vacuum brakes, disconnect lines
from vacuum pump.
14. Attach overhead lifting equipment and
raise until power plant is partially supported; then
O tt-U elu cle Gam*
VALVE SPRING REPLACEMENT
(CYLINDER HEAD INSTALLED)
In most vehicles it is possible to replace a
broken valve spring without removing cylinder
head from engines by following procedure below:
When it is necessary to replace a valve spring
and/or seals on valve stem s, the tool (J-21544)
also used for changing valve springs on V6 gaso­
line engine, is used to facilitate the operation.
Proceed in following manner to replace valve
spring and retaining parts:
1. Remove rocker arm cover.
2. Turn engine crankshaft until piston is at
upper-dead-center on cylinder at which work is to
be performed.
NOTE: The mark on crankshaft damper may
be used as reference point - while observing valve
G M C S E R V I C E M A N U A L
remove front and rear mounting bolts.
to prevent fouling of lines and wiring.
gine, making reference to appropriate sections of
manual for additional information required to
properly separate the components.
INSTALLATION
SIONS AND CLUTCHES (SEC. 7) of this manual
for information required to properly assemble
clutch parts and transm ission to engine.
balance as engine is lifted into position.
lift power plant into place. Locate engine front and
rear mountings and install mounting bolts. Refer
to ENGINE MOUNTINGS (SEC. 6D) for necessary
information regarding engine mountings.
uum pump is used), lubricating oil lines, electrical
wiring, and radiator and heater hoses. Connect oil
cooler lines.
drive. Also, connect tachometer drive (whenused).
road draft tube and filter (fig. 1) at rear of engine.
and transmission control rods.
proper level with engine oil.
and start engine. Adjust controls and inspect for
oil leaks.
action - to locate dead-center on #1 and #4 cylin­
ders. When piston is at upper center on com pres­
sion stroke there will be no rocker arm movement
at cylinder in which firing is to occur.
from cylinder head, then use tool to compress
valve spring and release valve keys.
com pressor tool and remove spring seat, inner
spring, and outer spring. At intake valve, remove
valve stem oil seal from groove in stem . Valve
rotator may also be removed if necessary.
TORO-FLOW DIESEL ENGINE
15. Lift power plant out of chassis, using care
16. Remove transm ission and clutch from en­
Refer to applicable portion of TRANSMIS­
1. Attach overhead hoist in manner to provide
2. With mounting brackets in place on engine,
3. Connect air lines (or vacuum lines if vac­
4. Connect propeller shaft and speedometer
5. Connect clutch control linkage. Also, install
6. Install control island and connect all wiring
7. Fill cooling system and check for leaks.
8. Make certain engine crankcase is filled to
9. Connect battery cables, prime fuel system ,
3. Remove rocker arm and shaft assembly
4. Remove valve keys, then release spring
CAUTION: DO NOT turn engine crank­
shaft while springs are removed from
valve, since valve may fall out of guide
and into cylinder as piston reaches bot­
tom of stroke.
Sec. 6B
Page 295