GMC S Series 1994, Repair Manual

Page: 416 / 919

DISASSEMBLY OF THE ENGINE
TOOLS AND SHOP EQUIPM ENT
A clean, well-lit, work area should be available. Other
necessary equipment 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 help aid with the
work and help prevent personal injury or component
damage.
Special tools are listed and illustrated throughout this
section with a complete listing at the end of the section.
These tools (or their equivalents) are specially designed
to quickly and safely accomplish the operations for
which they are intended. The use of these special tools
will also minimize possible damage to engine compo­
nents.
Some precision measuring tools are required for
in sp e ctio n of ce rta in c ritic a l com ponents. Torque
wrenches are necessary for the correct assembly of
various parts.
ACCESSORY REMOVAL
The various procedures in this manual assume that
the engine accessories have been removed. These
accessories may include one or more of the following:
• Power Steering Pump
• Drive Belt Tensioner
• Generator
• Air Conditioning Compressor
• Cooling Fan
• Distributor
It is beyond the scope of this section to cover in detail
the many different accessory installations. Refer to the
proper Light Duty Truck Service Manual for this infor­
mation.
Diagrams of emissions and vacuum hose routings,
wiring harness routing, accessory drive belt layout, etc.
should be found or made before removing accessories.
CLEANING
Remove the engine accessories before cleaning to
provide better access to the engine’s exterior surfaces.
After removing the distributor, accessory brackets, etc.,
cover the openings with tape to prevent the entry of
contaminants.
Methods used to clean the engine will depend on the
means which are available. Steam cleaning, pressure
washing, or solvent cleaning are some of the accept­
able methods. Allow the engine to dry thoroughly before
beginning any work.
It is important that the engine be as clean as possible
to prevent dirt, water, or any other contaminants from
entering critical areas during disassembly.
D RAINING TH E ENGINE
Remove or Disconnect
1. Oil pan plug and washer and allow the oil to drain
from the pan.
2. Oil filter.
3. Coolant drain plugs from the block and allow the
coolant to drain.
Install or Connect
NOTICE: For step s 1 and 3, refer to “Notice’
on page 6A4-1.
1. Coolant drain plugs into the block.
Tighten
&
• Coolant drain plugs to 30 N-m (22 lbs. ft.).
2. Oil filter.
3. Oil pan drain plug and washer.
• Oil pan drain plug to 25 N-m (18 lbs. ft.).
EXHAUST MANIFOLD REMOVAL
Remove or Disconnect
1. Exhaust manifold bolts, washers, and tab washers.
2. Heat shields.
3. Exhaust manifold.
COOLANT PUMP REMOVAL
4- +
Remove or Disconnect
1. Coolant pump bolts.
2. Coolant pump.
3. Gaskets.
ROCKER ARM COVER REMOVAL
Remove or Disconnect (Figure 7)
1. Rocker arm cover bolts (1).
2. Rocker arm cover (2).
3. Gasket (3).