air condition GMC C-SERIES 1999 User Guide

yellowblue
3-7
Ventilation Tips

Keep the hood and front air inlet free of ice, snow or
any other obstruction (such as leaves). The heater
and defogger will work far better, reducing the
chance of fogging the inside of your windows.

When you enter a vehicle in cold weather, turn the
blower fan to high for a few moments before driving
off. This helps clear the intake ducts of snow and
moisture and reduces the chance of fogging the
inside of your windows.

Keep the air path under the seats clear of objects.
This helps air to circulate throughout your vehicle.
The air vents are located in the center and on the sides of
your instrument panel. You can move the vents to direct
the flow of air or close the vents altogether. When you
close a vent, it will increase the flow of air coming out
of any vents that are open.
If your vehicle does not have air conditioning, there are
air vent controls located below the instrument panel.Audio Systems
Your Delco Electronics audio system has been designed
to operate easily and give years of listening pleasure.
You will get the most enjoyment out of it if you acquaint
yourself with it first. Find out what your Delco
Electronics system can do and how to operate all its
controls, to be sure you're getting the most out of the
advanced engineering that went into it.
Setting the Clock
While pressing the SET button, press the UP button
until the correct hour appears on the display and the
DOWN button until the correct minute appears on the
display. If you press and hold the UP/DOWN button,
hours or minutes will advance rapidly.
ProCarManuals.com

yellowblue
5-6
If you have a diesel engine vehicle with two batteries
(or more), you should know before you begin that,
especially in cold weather, you may not be able to
get enough power from a single battery in another
vehicle to start your diesel engine.
If your vehicle has more than one battery, use the
battery that's closest to the starter
-- this will reduce
electrical resistance.
CAUTION:
If your vehicle has air conditioning, the auxiliary
electric fan under the hood can start up even
when the engine is not running and can injure
you. Keep hands, clothing and tools away from
any underhood electric fan.
2. Get the vehicles close enough so the jumper cables
can reach, but be sure the vehicles aren't touching
each other. You wouldn't be able to start your
vehicle, and the bad grounding could damage the
electrical systems.
3. Turn off the ignition on both vehicles. Turn off all
lamps that aren't needed, as well as radios. This willavoid sparks and help save both batteries, and it
could save your radio.
4. Locate the batteries on each vehicle. Find the
positive (+) and negative (
-) terminals on
each battery.
CAUTION:
Using a match near a battery can cause battery
gas to explode. People have been hurt doing this,
and some have been blinded. Use a flashlight if
you need more light.
Be sure the batteries have enough water. You
don't need to add water to the ACDelco
Freedom

battery (or batteries) installed in
every new GM vehicle. But if a battery has filler
caps, be sure the right amount of fluid is there.
If it is low, add water to take care of that first.
If you don't, explosive gas could be present.
Battery fluid contains acid that can burn you.
Don't get it on you. If you accidentally get it in
your eyes or on your skin, flush the place with
water and get medical help immediately.
ProCarManuals.com

yellowblue
5-19 If No Steam Is Coming From Your Engine
If you get an engine overheat warning but see or hear no
steam, the problem may not be too serious. Sometimes
the engine can get a little too hot when you:

Climb a long hill on a hot day.

Stop after high
-speed driving.

Idle for long periods in traffic.
If you get the overheat warning with no sign of steam,
try this for a minute or so:
1. If you have an air conditioner and it's on, turn it off.
2. Turn on your heater to full hot at the highest fan
speed and open the window as necessary.
3. If you're in a traffic jam, shift to NEUTRAL (N);
otherwise, shift to the highest gear while
driving
-- DRIVE (D) for automatic transmissions.
4. If climbing a hill, downshift to raise engine and
fan speeds.If you no longer have the overheat warning, you can
drive. Just to be safe, drive slower for about 10 minutes.
If the warning doesn't come back on, you can
drive normally.
If the warning continues, pull over, stop, and park your
vehicle right away.
If there's still no sign of steam, push down the
accelerator until the engine speed is about twice as fast
as normal idle speed for at least three minutes while
you're parked. If you still have the warning, turn off the
engine and get everyone out of the vehicle until it
cools down.
You may decide not to lift the hood but to get service
help right away.
ProCarManuals.com

yellowblue
5-21
CAUTION:
If your vehicle has air conditioning, the auxiliary
electric engine cooling fan under the hood can
start up even when the engine is not running and
can injure you. Keep hands, clothing and tools
away from any underhood electric fan.
If the coolant inside the coolant recovery tank is boiling,
don't do anything else until it cools down.
Specialty Hood
The coolant level
should be above the
HOT LEVEL mark on the
vehicle with the specialty
hood, or at or above the
COLD LEVEL mark
on the vehicle with the
sloped hood.
Sloped Hood
If it isn't, you may have a leak in the radiator hoses,
heater hoses, radiator, water pump or somewhere else in
the cooling system.
CAUTION:
Heater and radiator hoses, and other engine
parts, can be very hot. Don't touch them. If you
do, you can be burned.
CAUTION: (Continued)
ProCarManuals.com

yellowblue
5-27
Cooling System (Diesel Engine)
When you decide it's safe to lift the hood, here's what
you'll see:
Caterpillar
Diesel Engine
A. Engine Fan
B. Coolant Surge Tank
CAUTION:
If your vehicle has air conditioning, the auxiliary
electric engine cooling fan under the hood can
start up even when the engine is not running and
can injure you. Keep hands, clothing and tools
away from any underhood electric fan.
If the coolant inside the coolant surge tank is boiling,
don't do anything else until it cools down.
ProCarManuals.com

yellowblue
5-33
5. Then replace the pressure cap. Be sure the arrows on
the pressure cap line up like this.
Engine Fan Noise
Your vehicle has a clutched engine cooling fan. When
the clutch is engaged, the fan spins faster to provide
more air to cool the engine. In most everyday driving
conditions, the clutch is not fully engaged. This
improves fuel economy and reduces fan noise. Under
heavy vehicle loading, trailer towing and/or high outside
temperatures, the fan speed increases when the clutch
engages. So you may hear an increase in fan noise.
This is normal and should not be mistaken as the
transmission slipping or making extra shifts. It is merely
the cooling system functioning properly. The fan will
slow down when additional cooling is not required and
the clutch disengages.
You may also hear this fan noise when you start the
engine. It will go away as the fan clutch disengages.
ProCarManuals.com

6-
yellowblue
6-1
Section 6 Service and Appearance Care
Here you will find information about the care of your vehicle. This section begins with service and fuel information,
and then it shows how to check important fluid and lubricant levels. There is also technical information about your
vehicle, and a part devoted to its appearance care.
6
-2 Service
6
-4 Fuel (Gasoline Engine)
6
-5 Diesel Fuel Requirements and Fuel System
6
-6 Fuels in Foreign Countries (Gasoline Engines)
6
-7 Filling Your Tank
6
-8 Filling a Portable Fuel Container
6
-9 Checking Things Under the Hood
6
-11 Noise Control System
6
-13 Engine Oil (Gasoline Engine)
6
-17 Engine Oil (Caterpillar
Diesel Engine)
6
-17 Engine Air Cleaner/Filter
6
-18 Automatic Transmission Fluid
6
-19 Manual Transmission Fluid
6
-20 Rear Axle
6
-20 Rear Axle Shift Motor (Option)
6
-21 Radiator Pressure Cap (Gasoline Engines)
6
-22 Surge Tank Pressure Cap (Diesel Engines)
6
-22 Thermostat6
-23 Engine Coolant (Gasoline Engine)
6
-27 Engine Coolant (Caterpillar
Diesel Engine)
6
-28 Power Steering Fluid
6
-29 Windshield Washer Fluid
6
-30 Brakes
6
-36 Electric/Hydraulic Parking Brake Fluid
6
-42 Battery
6
-44 Other Service Items
6
-48 Tires
6
-59 Appearance Care
6
-59 Cleaning the Inside of Your Vehicle
6
-63 Cleaning the Outside Your Vehicle
6
-66 GM Vehicle Care/Appearance Materials
6
-67 Vehicle Identification Number (VIN)
6
-67 Service Parts Identification Label
6
-68 Electrical System
6
-74 Capacities and Specifications
6
-77 Air Conditioning Refrigerants
ProCarManuals.com

yellowblue
6-27
CAUTION:
Turning the radiator pressure cap (on a gasoline
engine) or the surge tank cap (on a diesel engine)
when the engine and radiator are hot can allow
steam and scalding liquids to blow out and burn
you badly. With the coolant recovery system, you
will almost never have to add coolant at the
radiator. Never turn the radiator pressure cap
or the surge tank pressure cap
-- even a
little
-- when the engine and radiator are hot.
Add coolant mixture at the recovery tank or the surge
tank, but be careful not to spill it.
CAUTION:
You can be burned if you spill coolant on hot
engine parts. Coolant contains ethylene glycol,
and it will burn if the engine parts are hot
enough. Don't spill coolant on a hot engine.
Some conditions, such as trapped air in the cooling
system, can affect the coolant level in the radiator. If you
need to add coolant to the radiator, follow the steps
listed under ªHow to Add Coolant to the Radiator.º
See ªEngine Overheatingº in the Index.
Engine Coolant
(Caterpillar
Diesel Engine)
If your vehicle has a Caterpillar diesel engine, see the
Caterpillar
Operation & Maintenance Manual provided
with your vehicle to find out what to add, also when and
how to service your cooling system.
ProCarManuals.com

yellowblue
6-47 Front Wheel Bearings with Oil-Filled Hubs
If your vehicle has oil-filled
hubs, occasionally check to
see if they have enough oil.
You can tell by looking into
the sight glass to see if there
is oil there.
If there isn't, clean the rubber fill plug in the center of
the glass, and then remove it. Be careful not to allow
any dirt or water to get into the oil. Add enough of the
recommended oil to bring it up to the level mark that
you'll see on the glass.
Refer to your Maintenance Schedule for the proper oil
to use.
When you fill the hub, check the glass again after
driving a short distance. It takes a while for the oil to
flow through the system, and you may find that you
have to add a little more to fill it to the proper level.
Air Conditioning System
Every now and then, have your dealership check your
air conditioning system to be sure it has not lost any
cooling ability. If you think the system is not working
properly, have your GM Truck dealer check it out as
soon as possible.
The air conditioning won't work when the temperature
outside is below 40
F (4
C).
NOTICE:
If your vehicle is equipped with factory air
conditioning, the system is charged with the
R
-134a refrigerant. Servicing of the air
conditioning system should be performed by a
trained service technician.
ProCarManuals.com

yellowblue
6-50 Rims and Wheels
Rims and wheels are stamped with a maximum load and
cold inflation rating. Be sure you don't exceed these limits.
Dual Tire Operation
When the vehicle is new, or whenever a wheel, wheel
bolt or wheel nut is replaced, check the wheel nut torque
as indicated:
If your vehicle has stud piloted or hub piloted wheels,
tighten the wheel stud nuts to the specified torque values
at 100 miles (160 km), 500 miles (800 km) and
1,000 miles (1 600 km) and then every 1,000 miles
(1 600 km) thereafter.
For proper torque, see ªWheel Nut Torqueº 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 ªChanging a
Flat Tireº in the Index for more information.
CAUTION:
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, if any) are
properly inflated.
ProCarManuals.com