Disassembly; Tools And Shop Equipment; Accessory Removal; Cleaning - GMC 1989 Light Duty Truck Repair Manual

Figure 3— Rocker Arm Cover Installation

TOOLS AND SHOP EQUIPMENT

A clean, well lit work area should be available. Other
necessary equipm ent includes: A suitable parts cleaning
tank, compressed air supply, trays to keep parts and
fasteners organized, and an adequate set of hand tools.
An approved engine repair stand will aid the work and
help prevent personal inju ry or dam age to engine
components.
Special tools are illustrated throughout this section, and
are listed at its end. These tools (or their equivalents) are
specially designed to quickly and safely accomplish the
operations for which they are intended. The use of these
tools will also m inim ize possible dam age to engine
components.
Some precision m easuring tools are required for
in s p e c tio n of c e rta in c ritic a l co m p o n e n ts . Torque
wrenches will be necessary for correct assem bly of
various parts.

ACCESSORY REMOVAL

This manual assumes that the engine accessories have
been removed. These accessories may include one or
more of the following:
Hydraulic Pump
AIR Pump
Generator
Air Conditioning Compressor

DISASSEMBLY

Cooling Fan
Distributor
Carburetor
TBI Unit
It is beyond the scope of this section to detail the many
different accessory installations. Refer to the proper Truck
Service Manual for this information.
Diagrams of emission and vacuum hose routings,
wiring harness routing, accessory drive belt layout, etc.,
should be made before removing accessories.
Remove the engine accessories before cleaning, to
provide better access to engine exterior surfaces. After
removing the carburetor, TBI unit, distributor, fuel pump,
etc., cover the openings with tape to prevent the entry of
water, solvent and dirt.
Methods used to clean the engine will depend on the
aids w hich are available. Steam cleaning, pressure
w ashing, or solvent c lea nin g are som e accep tab le
methods. Allow the engine to dry before beginning the
work.
It is important that the engine be as clean as possible to
p re v e n t d ir t fro m
disassembly.
F-05520
R em ove or D isconnect
1. Oil pan plug and allow the oil pan to drain.
2. Oil filter.
3. Block drains and allow the coolant to drain.
- ►+
Install or C onnect
1. Oil pan plug and washer.
2. Block drain plugs.
Rem ove or D isconnect
1. Bolts.
2. EGR valve.
3. Gasket.

EXHAUST MANIFOLD REMOVAL

R em ove or D isconnect
1. Exhaust manifold bolts, washers, and tab washers.
2. Heat shield (if equipped).
3. Exhaust manifold.
4.3 LITER V-6 6A3-5

CLEANING

e n te rin g c r itic a l a re a s d u rin g

DRAINING THE ENGINE

T ighten
• Block drain plugs to 14 N m (10 ft. lbs.).

EGR VALVE REMOVAL