tow GMC C-SERIES 1999 Owner's Manual

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3-6 Defogging
Use DEFOG, along with the HEATER setting, when
there is fog or ice on the windshield. This will direct
airflow toward the windshield and front side windows.
Set the temperature selector toward H and the fan
control at a comfortable level. When the windshield is
clear, use the temperature selector bar and the fan
control button to maintain a comfortable
temperature level.
Ventilation System
Air comes into your vehicle in one of two ways: power air
or ram air. Power air means bringing outside air into the
cab through the air intake, using the blower fan. Fresh air
can be drawn in when the vehicle is stationary or moving
at low speed. Air comes in through four vents in the
instrument panel and is exhausted through the vents and
pressure relief valves in the doors and door pillars. Power
ventilation means an increased supply of fresh air is
brought into the cab interior without having to open the
windows, especially during inclement weather.
Ram air is forced into the cab through the air intake in
the cowl by the vehicle's forward motion. This air is
controlled by two vent air handles under the instrument
panel. Air is directed through the ventilation ducts to the
floor. Ram air provides good airflow into the cab at
normal road speeds.
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5-
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5-1
Section 5 Problems on the Road
Here you'll find what to do about some problems that can occur on the road.
5
-2 Hazard Warning Flashers
5
-3 Other Warning Devices
5
-5 Jump Starting
5
-9 Towing Your Vehicle
5
-18 Engine Overheating
5
-20 Cooling System (Gasoline Engine)5
-27 Cooling System (Diesel Engine)
5
-33 Engine Fan Noise
5
-34 If a Tire Goes Flat
5
-34 Changing a Flat Tire
5
-37 If You're Stuck: In Sand, Mud, Ice or Snow
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5-9
A. Heavy Metal Engine Part
B. Good Battery
C. Dead Battery
Towing Your Vehicle
Try to have a GM dealer or a professional towing
service tow your vehicle. They can provide the right
equipment and know
-how to tow it without damage.
Before you do anything, turn on the hazard warning
flashers (if they have not been damaged).
When you call, tell the towing service:

The make, model and year of your vehicle.

Whether you can still move the shift lever.

If there was an accident, what was damaged.
When the towing service arrives, let the tow operator
know that this manual contains detailed towing
instructions. The operator may want to see them.
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5-10
CAUTION:
To help avoid injury to you or others:

Never let passengers ride in a vehicle that is
being towed.

Never tow faster than safe or posted speeds.

Never tow with damaged parts not
fully secured.

Never get under your vehicle after it has
been lifted.

Always use separate safety chains on each
side when towing a vehicle.
If your vehicle uses dragfoilers, be sure to have the
dragfoiler
-to-cab mounting bracket bolts tightened after
your vehicle has been towed.
Here are specific towing instructions:
Towing Your Vehicle From the
Front (Front Wheels Off the Ground)
Before Towing
Block the rear wheels of the disabled vehicle. On
vehicles with air brakes, release the emergency brake
system by compressing the brake chamber springs as
outlined in this section. (Note: This is to prevent the
possibility of the emergency brake being applied
during towing.)
On vehicles with hydraulic brakes without an
electric/hydraulic parking brake, release the
parking brake fully by moving the lever to the
fully
-released position.
On vehicles equipped with an electric/hydraulic parking
brake option, remove the propshaft.
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5-11
Towing the Vehicle with the Front Bumper Removed
1. Remove the front bumper.
2. Connect and lock the lift chains to the front axle,
outside of the spring anchor plates as shown.
A. Spring Anchor Plate
B. Lift Chain
C. Front Axle
3. Place a 6, x 6, x 5
hardwood beam underneath and
slightly behind the front spring shackle brackets.4. Connect lift chains to the tow bar and raise the tow
bar until lift chain slack has been taken up and the
hardwood beam is fully seated against the spring
shackle brackets as shown.A. Shackle Bracket
B. Tow Bar
C. Lift Chain
D. Hardwood Beam
5. Raise the vehicle to the required height.
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5-12
Towing the Vehicle with the Front Bumper Installed
1. Connect and lock the lift chains to the front axle,
outside of the spring anchor plates as
previously shown.
2. Place a 6, x 6, x 5
hardwood beam underneath and
slightly behind the front spring shackle brackets as
previously shown.
3. Connect the lift chains to the tow bar and take up the
slack in the chains until the tow bar is within 4, of
the front bumper facing. Place a 2, x 12, x 40,
hardwood board with rubber pads against the front
bumper and secure as shown.
A. Rubber Pad
B. Hardwood Board
C. Shackle Bracket
D. Lift ChainE. Hardwood Beam
F. Bumper
G. Tow Bar
4. Remove the remaining slack in the lift chains.
The tow bar swing arm should rest against the
2, x 12, x 40, hardwood board as shown.
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5-14
After Towing
Block the rear wheels and install axle and propeller
shafts. Check for proper phasing of universal joints.
Apply the emergency brake system before disconnecting
from the towing vehicle. Check and fill the rear axle
with oil as required.
Towing Your Vehicle From the Front
(All Wheels On the Ground)
Your vehicle may be towed on all wheels provided the
steering is working. Remember that the power brakes
and power steering will not have power assist. Vehicles
with air brakes will not have brakes. There must be a
tow bar installed between the towing vehicle and the
disabled vehicle.
Before Towing
Block the wheels of the disabled vehicle. On vehicles
with air brakes, release the emergency brake system by
compressing the brake chamber springs as outlined in
this section. (Note: This is to prevent the possibility of
the emergency brake being applied during towing.)On vehicles with hydraulic brakes, release the
parking brake fully by moving the lever to the
fully
-released position.
On vehicles equipped with an electric/hydraulic parking
brake, remove the propshaft.
Disconnect the propshaft at the rear axle (forward axle
on tandem axle models). Secure the propshaft to the
frame or crossmember.
If there is damage or suspected damage to the axle(s),
remove the axle shafts. Cover the hub openings to
prevent the loss of lubricant or entry of dirt or
foreign objects.
After Towing
Block the rear wheels and install axle and propshafts.
Check for proper phasing of universal joints. Apply
the parking brake system before disconnecting from
the towing vehicle. Check and fill rear axle with oil
as required.
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5-15 Towing Your Vehicle From the Rear
(Rear Wheels Off the Ground)
Before Towing
Secure the steering wheel to maintain a straight
-ahead
position. Make certain that the front axle is not loaded
above the front axle Gross Axle Weight Rating (GAWR)
as indicated on the vehicle's Certification/Tire label.
After Towing
Block the rear wheels and release the steering. Apply the
parking brake system before disconnecting from the
towing vehicle.
Refer to the transmission shift label for
additional information.
Releasing Air-Operated Parking Brakes
If your vehicle has air brakes, you could have a special
towing problem. If your vehicle has to be towed because
you had a complete loss of air pressure from both
systems, the parking brakes may have applied. The tow
operator can release the brakes manually by using the
following steps. Then your vehicle can be towed with all
wheels or just the rear wheels on the ground.
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5-16
CAUTION:

Working on air brakes without first using
the release studs to compress the springs
can lead to injury. Never work on the air
brake chambers without first using the
release studs to compress the brake springs.

When the brake springs are manually
compressed, you will have no brakes.
Release your air
-operated parking brakes
manually only to tow the vehicle. Never
drive the vehicle with the brakes released.
1. Block the wheels of the vehicle.
2. Remove the release stud and nut from the side of the
brake chamber. Some chambers have studs which are
visible at all times.
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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.
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