1997 CHEVROLET EXPRESS air condition

Downloaded from www.Manualslib.com manuals search engine Adding Equipment to the Outside of
Your Vehicle
Things you might add to the outside of your vehicle can
affect the airflow around it. This may cause wind noise
and affect windshield washer performance. Check with
your
GM dealer before adding equipment to the outside
of your vehicle.
Fuel (Gasoline Engine)
If your vehicle has a diesel engine, see “Diesel Fuel
Requirements and Fuel System” in the Diesel Engine
Supplement. For vehicles with gasoline engines, please
read this.
Use regular unleaded gasoline rated at 87 octane or
higher. At a minimum, it should meet specifications
ASTM
D48 14 in the United States and CGSB 3.5-M93
in Canada. Improved gasoline specifications have been
developed by the American Automobile Manufacturers
Association (AAMA) for better vehicle performance
and engine protection. Gasolines meeting the AAMA
specification could provide improved driveability and
emission control system protection compared to
other gasolines. Be
sure the posted octane is at least 87. If the octane
is
less than 87, you may get a heavy knocking noise when
you drive. If it’s bad enough, it can damage your engine.
If you’re using fuel rated at 87 octane or higher and you
hear heavy knocking, your engine needs service.
But
don’t worry if you hear a little pinging noise when
you’re accelerating or driving up a hill. That’s normal,
and
you don’t have to buy a higher octane fuel to get rid
of pinging. It’s the heavy, constant knock that means
you have a problem.
If your vehicle is certified to meet California Emission
Standards (indicated on the underhood tune-up label),
it
is designed to operate on fuels that meet California
specifications.
If such fuels are not available in states
adopting California emissions standards, your vehicle
will operate satisfactorily on fuels meeting federal
specifications, but emission control system performance
may be affected. The malfunction indicator lamp on
your instrument panel may turn on and/or your vehicle
may fail a smog-check test. If this occurs, return to your
authorized
GM dealer for diagnosis to determine the
cause of failure.
In the event it is determined that the
cause of the condition is the type
of fuels used, repairs
may not be covered by your warranty.

Downloaded from www.Manualslib.com manuals search engine If your vehicle has a 7.4 liter engine and air
conditioning, your vehicle will have
a auxiliary engine
fan in addition to the belt driven fan.
1
,A CAUTION: I
If your vehicle has air conditioning, the auxiliary
engine fan under the hood can start up and
injure you even when the engine is not running.
Keep hands, clothing and tools away from any
underhood electric fan.
I A CAUTION:
i
Things that burn can get on hot engine parts and
start
a fire. These include liquids like gasoline,
oil, coolant, brake fluid, windshield washer and
other fluids, and plastic or rubber. You
or others
could be burned. Be careful not to drop or spill
things that will burn onto
a hot engine.
Before closing the hood, be sure all the filler caps are
on properly.
Then
lift the hood to relieve pressure on the hood prop.
Remove the hood prop from the slot in the hood and
return the prop
to its retainer. Then just let the hood
down and close
it firmly.
6-10
. .~

Downloaded from www.Manualslib.com manuals search engine Operating the engine with the air cleaner off
can cause you or others to be burned. The air
cleaner not only cleans the air,
it stops flame if
the engine backfires. If it isn’t there, and the
engine backfires, you could be burned. Don’t
drive with it
off, and be careful working on the
engine with the air cleaner off.
NOTICE:
If the air cleaner is off, a backfire can cause a
damaging engine fire. And, dirt can easily get
into your engine, which will damage it. Always
have the
air cleaner in place when you’re driving.
Automatic Transmission Fluid
When to Check and Change
A good time to check your automatic transmission fluid
level is when the engine oil is changed.
Change both the fluid and filter every
50,000 miles
(83 000 km) if the vehicle’s GVWR is over 8,600 or
if the vehicle is mainly driven under one or more of
these conditions:
0 In heavy city traffic where the outside temperature
regularly reaches
90°F (32°C) or higher.
0 In hilly or mountainous terrain.
0 When doing frequent trailer towing.
0 Uses such as found in taxi, police or delivery service.
If your vehicle’s
GVWR is not over 8,600 and you do
not use your vehicle under any of these conditions, the
fluid and filter do not require changing.
See “Scheduled Maintenance Services”
in the Index.

Downloaded from www.Manualslib.com manuals search engine Dual Tire Operation
When the vehicle is new, or whenever a wheel, wheel
bolt or wheel nut is replaced, check the wheel
nut torque
after
100, 1,000 and 6,000 miles ( 160, 1 600 and
10 000 km) of driving. For proper torque, see “Wheel
Nut Torque’’ in
the Index.
The outer tire on a dual wheel setup generally wears
faster than the inner tire. Your tires will wear more
evenly and last longer if you rotate the tires periodically.
If you’re going to be doing a lot
of driving on
high-crown roads, you can reduce tire wear by adding
5 psi (35 kPa) to the tire pressure in the outer tires. Be
sure
to return to the recommended pressures when no
longer driving under those conditions. See “Changing a
Flat Tire” in the Index for more information.
A CAUTION:
Buying New Tires
To find out what kind and size of tires you need, look at
the Certificationrnire label.
The tires installed
on your vehicle when it was new had
a Tire Performance Criteria Specification (TPC Spec)
number
on each tire’s sidewall. When you get new tires,
get ones with that same TPC Spec number. That way
your vehicle will continue
to have tires that are designed
to give proper endurance, handling, speed rating,
traction, ride and other things during normal service on
your vehicle. If your tires have an all-season tread
design, the TPC number will be followed by
an “MS”
(for mud and snow).
If you ever replace your tires with those not having a
TPC Spec number, make sure they are the same size,
load range, speed rating and construction type (bias,
bias-belted or radial) as your original tires.
If you operate your vehicle with a tire that is
badly underinflated, the tire can overheat. An
overheated tire can lose air suddenly or catch
fire.
You or others could be injured. Be sure all
tires (including the spare) are properly inflated.

Downloaded from www.Manualslib.com manuals search engine Temperature -- A, B, C
The temperature grades are A (the highest), B, and C,
representing the tire’s resistance to the generation of
heat and its ability
to dissipate heat when tested under
controlled conditions on a specified indoor laboratory
test wheel. Sustained high temperature can cause the
material of the tire
to degenerate and reduce tire life, and
excessive temperature can lead to sudden tire failure.
The grade
C corresponds to a level of performance
which all passenger car tires must meet under the
Federal Motor Vehicle Safety Standard
No. 109. Grades
B and A represent higher levels of performance on the
laboratory test wheel than the minimum required by law.
Warning: The temperature grade for this tire is
established for a tire that is properly inflated and not
overloaded. Excessive speed, underinflation, or
excessive loading, either separately or in combination,
can cause heat buildup and possible tire failure.
Wheel Alignment and Tire Balance
The wheels on your vehicle were aligned and balanced
carefully
at the factory to give you the longest tire life
and best overall performance. Scheduled
wheel alignment
and wheel balancing are not
needed. However, if you notice unusual tire wear or
your vehicle pulling one way or the other, the alignment
may need
to be reset. If you notice your vehicle
vibrating when driving
on a smooth road, your wheels
may need to be rebalanced.
Wheel Replacement
Replace any wheel that is bent, cracked, or badly rusted
or corroded. If wheel nuts keep coming loose, the wheel,
wheel bolts and wheel nuts should be replaced.
If the
wheel leaks air, replace
it (except some aluminum
wheels, which can sometimes be repaired). See your
GM dealer if any of these conditions exist.
Your dealer will know
the kind of wheel you need.
Each new wheel should have the same load-carrying
capacity, diameter, width, offset and be mounted the
same way as the one it replaces.
If
you need to replace any of your wheels, wheel bolts
or wheel nuts, replace them only with new
GM original
equipment parts. This way, you will
be sure to have the
right wheel, wheel bolts and wheel nuts for your vehicle.

Downloaded from www.Manualslib.com manuals search engine Finish Damage
Any stone chips, fractures or deep scratches in the finish
should be repaired right away. Bare metal will corrode
quickly and may develop into a major repair expense.
Minor chips and scratches can be repaired with touch-up
materials available from your dealer or other service
outlets. Larger areas of finish damage can be corrected
in your dealer’s body and paint shop.
Underbody Maintenance
Chemicals used for ice and snow removal and dust control
can collect on the underbody.
If these are not removed,
accelerated corrosion (rust) can occur on the underbody
parts such as fuel lines, frame, floor pan and exhaust
system even though they have corrosion protection.
At least every spring, flush these materials from the
underbody with plain water. Clean any areas where mud
and other debris can collect. Dirt packed
in closed areas
of the frame should be loosened before being flushed.
Your dealer or an underbody car washing system can do
this for
you.
Chemical Paint Spotting
Some weather and atmospheric conditions can create a
chemical fallout. Airborne pollutants can fall upon and
attack painted surfaces on your vehicle. This damage
can take two forms: blotchy, ringlet-shaped
discolorations, and small irregular dark spots etched
into
the paint surface.
Although no defect in the paint job causes this,
GM will repair, at no charge to the owner, the surfaces
of new vehicles damaged by this fallout condition
within
12 months or 12,000 miles (20 000 km) of
purchase, whichever occurs first.
This applies
only to materials manufactured and sold by
General Motors. Bodies, body conversions or equipment
not made or sold
by General Motors are not covered.

Downloaded from www.Manualslib.com manuals search engine Engine Compartment Fuse Relay Center
The fuse block is on the driver’s side of the engine
compartment at the rear.
,
[T)
Name
BLOWR
ABS
Circuits Protected
Blower Motor
Electronic Brake Control Module
Name
IGN-B
IGN-A
BATT
LIGHTING
RR BLOWER
ENG-
1
AIC
SPARE
AUX A
AUX-B
RH-HDLP
Circuits Protected
Ignition Switch
Starter Relay, Ignition Switch
Instrument Panel Fuse Block
Instrument Panel Fuse Block,
Headlamp Switch
Rear Auxiliary Blower
Motor Relays
Heated
02 Sensors, Mass Air
Flow Sensor, EGR Valve
Solenoid, Evap Canister Purge
Valve, Crankshaft Position Sensor,
Secondary Air Injection Relay
(Diesel), Water in Fuel Sensor
(Diesel), Fuel Heater (Diesel),
Glowplug
Relay (Diesel),
Wastegate Solenoid (Diesel)
Air Conditioning Clutch Relay
Spare Fuses
Upfitter Provisions
Upfitter Provisions
Right-hand Headlamp (Export Only)
6-63

Downloaded from www.Manualslib.com manuals search engine Name
RH-HIBM
ECM-I
HORN LH-HDLP
LH-HIBM
FUEL SOL
IGN-E
ECM-B
Circuits Protected
Right-hand High-beam Headlamp (Export Only)
Ignition Coil, Crankshaft Position
Sensor, VCM, Fuel Injectors,
Coil Driver
Horn Relay, Underhood Lamp(
s)
Left-hand Headlamp
(Export Only)
Left-hand High-beam Headlamp (Export Only)
PCM,
Fuel Solenoid Driver,
Engine Shutoff Solenoid
Air Conditioning Clutch Relay
Fuel Pump Relay, VCM, PCM,
Fuel Pump and Engine Oil
Pressure Switch
Capacities and Specifications
Replacement Parts
Replacement part numbers listed in this section are
based on the latest information available at the time
of
printing, and are subject to change. If a part listed in this
manual
is not the same as the part used in your vehicle
when
it was built, or if you have any questions, please
contact your
GM truck dealer.
These specifications are for information only. If you
have any questions, see the service manual for the
chassis
or refer to the body manufacturer’s publications.