light CHEVROLET SUBURBAN 1996 Repair Manual

Maintenance When Trailer Towing
Your vehicle will need service more often when you’re pulling a trailer. See
the Maintenance Schedule for more on this. Things that are especially
important
in trailer operation are automatic transmission fluid (don’t
overfill), engine oil, axle lubricant, belt, cooling system, an\
d brake
adjustment. Each
of these is covered in this manual, and the Index will help
you find them quickly. If you’re trailering, it’s a good idea to review these
sections before you start your trip.
Check periodically to see
that all hitch nuts and bolts are tight.
Trailer Lighting Systems Wiring
See “Trailer Wiring Harness” in the Index.
ProCarManuals.com

Turn off the ignition on both vehicles. Turn off all lights that aren’t
needed, and radios. This will avoid sparks and help save both batteries.
And it could
save your radio!
I NOTICE:
If you leave your radio on, it could be badly damaged. The
repairs wouldn’t be covered by your warranty.
Open the hoods and locate the batteries. Find the positive (+) and
negative
(-) terminals on each battery.
Check that the jumper cables don’t have loose or missing insulation. If
they do, you could get a shock. The vehicles could be damaged, too.
Before
you connect the cables, here are some basic things you should
know. Positive
(+) will go to positive (+) and negative (-) will go to
negative (-) or a metal engine part. Don’t connect (+) to (-) or you’ll
get a short that would damage the battery and maybe other parts, too.
5-4
ProCarManuals.com

If You’re Stuck: In Sand, Mud, /ce or Snow
What you don’t want to do when your vehicle is stuck is to spin your wheels
too fast. The method known as “rocking” can help you get out when you’re
stuck, but you must use caution.
I NOTICE:
Spinning your wheels can destroy parts of your vehicle as well as
the tires. If you spin the wheels too fast while shifting you\
r
transmission back and forth, you can destroy your transmission. \
For information about using tire chains on your vehicle, see “Tire Chains”
in the Index.
Rocking your vehicle to get it out:
First, turn your steering wheel left and right. That will clear the area around
your front wheels. Then shift back and forth between REVERSE (R) and a
forward gear (or with a manual transmission, between FIRST
(1) or
SECOND
(2) gear and REVERSE), spinning the wheels as little as possible.
Release the accelerator pedal while you shift, and press lightly on the
accelerator pedal when the transmission
is in gear. If that doesn’t get you
out after a few tries, you may need to be towed out. Or, you can use your
recovery hooks,
if your vehicle has them. If you do need to be towed out,
see “Towing Your Vehicle” in the Index.
5-41
ProCarManuals.com

You should ask your service station operators if their gasolines contain
deposit control additives and oxygenates, and
if they have been
reformulated
to reduce vehicle emissions.
Diesel Fuel Requirements and Fuel System
Some states and provinces have restrictions on the purchase of diesel fuel
for light-duty vehicles and require you
to buy permits or pay special taxes.
Some
of these restrictions apply only to residents, and others apply to both
residents and visitors. These restrictions can change.
To learn the current
restrictions
in any state or province, contact your auto club, the police or
other officials.
Fuel Requirements
NOTICE:
Diesel fuel or fuel additives not recommended in this manual
could damage your fuel system and engine. Your warranty
wouldn’t cover this damage. And:
Diesel fuel that has been mixed with engine oil could damage
your engine and emission controls.
Always check with your
service station operator to make sure his diesel fuel has not \
been mixed with engine oil.
If you ever run out of diesel fuel, it can be difficult to restart
your engine. “Running Out
of Fuel,” later in this section, tells
you how to get it started again.
To avoid all this, try never to
let your tank get empty.
What Fuel to Use
For best results, use Number 2-D diesel fuel year-round (above and below
freezing conditions) as
oil companies blend Number 2-D fuel to address
climate differences. Number 1-D diesel fuel may be used
in very cold
temperatures (when it stays below
0°F or -1 8°C); however, it will produce
a power and fuel economy
loss. The use of Number 1-D diesel fuel in warm
or hot climates may result in stalling, poor starting when the engine
is hot
and may damage the fuel injection system.
Diesel fuel may foam when you fill your tank. This can cause the automatic
pump nozzle
to shut off, even though your tank isn’t full. If this happens,
just wait for the foaming
to stop and then continue to fill your tank.
6-4
ProCarManuals.com

If this happens, a WATER IN FUEL light will come
water must be drained. Your Cfpder can show you
hc
I
WATER
IN
FUEL
If the light comes on at any other time, use this chart.
! on. If it does, the excess
3w to do this.
This light
also should
come
on briefly when
you start your engine,
as a check. If it
doesn’t, have it fixed
so it will be there to
let you know if you
ever do get water
in
your fuel.
NOTICE:
If you drive when this warning light is on, you can damage your \
fuel injection system and your engine. If the light comes on \
right
after you refuel,
it means water was pumped into your fuel tank.
Turn off your engine immediately. Then, have the water drained \
at once.
“WATER IN FUEL” LIGHT CHART Problem
Light comes on intermittently.
Light stays on:
Recommended Action
Drain water from fuel filter.
1. At temperatures above freezing. Drain fuel filter immediately. If no
water can be drained and light stays
on, see your dealer for assistance.
2. At temperatures below freezing. Drain fuel filter immediately. If no
water can be drained-water may
be frozen. Open the air bleed valve
to check for fuel pressure. If
no fuel
pressure is present, replace the fuel
filter.
3. Immediately after refueling -
large amount of water possibly
pumped into fuel tank. Fuel tank
purging required. See
your dealer for assistance.
6-4
ProCarManuals.com

Hesitation or “flat” performance at high speed or during hard acceleration
may be an indication of premature fuel filter plugging due
to dirty or
contaminated fuel. The filter element may need to be changed
if this
happens. See your dealer for assistance.
To drain water:
I. Stop and park the vehicle in a safe place. Turn off the engine and apply
the parking brake.
2. Remove the fuel tank cap.
3. Place a fuel-resistant container under the filter drain hose.
4. With the engine
off? open the
water drain valve
2 to 3 turns.
When standing
in
front of the
vehicle, the valve is located
on the
right side of the
thermostat housing.
5. Start the engine and allow it to idle until clear fuel is observed.
6. Stop the engine and close the water drain valve.
7. Remove the fuel-resistant container and properly dispose of the
contaminated fuel.
To find out how to properly dispose of contaminated
diesel fuel see “What to Do
with Used Oil” in the “Engine Oil (Diesel
Engines)” part, later
in this section.
8. Install the fuel tank cap.
If the WATER IN FUEL light comes on again after driving a short distance
or the engine runs rough or stalls-a large amount of water has probably
been pumped
into the fuel tank. The fuel tank should be purged.
6% CAUTION:
Diesel he1 containing water is still flammable. You could be
burned. If you ever try to drain water from
your fuel, keep
sparks, flames and smoking materials away
from the mixture.
6-7
ProCarManuals.com

You should also use the proper viscosity oil for your vehicle, as shown in
the following chart:
LIGHT DUTY EMISSIONS - GASOLINE ENGINES
RECOMMENDED SAE VISCOSITY GRADE ENGINE OILS
FOR BEST FUEL ECONOMY AND COLD STARTING, SELECT THE LOWEST
SAE VISCOSITY GRADE
011 FOR THE EXPECTEO TEMPERATURE RANGE.
HOT
WEATHER
7
'F
t 100
+ 80
+ 60
+ 40
+ 20
0
7
c
+38
- +27
- +16
- +4
--7
--18
WEATHER
-- ....-
SAE 5W-30
PREFERRED
LOOK
FOR THIS
SYMBOL
-
SAE 1OW-30
As shown in the chart, SAE 5W-30 is best for your vehicle. However, you
can use SAE 1 OW-30 if it's going to be 0°F (- 1 SOC) or above. These
numbers on
an oil container show its viscosity, or thickness. Do not use
other viscosity oils, such as SAE 20W-50.
6-1 7
ProCarManuals.com

NOTICE:
Use only engine oil with the American Petroleum Institute
Certified For Gasoline Engines “Starburst” symbol. Failure \
to
use the proper oil can result in engine damage not covered by
your warranty.
GM Goodwrench@ oil (in Canada, GM Engine Oil) meets all the
requirements for your vehicle.
Engine Oil Additives
Don’t add anything to your oil. Your GM dealer is ready to advise if you
think something should be added.
When to Change Engine Oil
See if any one of these is true for you:
Most trips are less than 5 to 10 miles (8 to 16 km). This is particularly
important when outside temperatures are below freezing.
0 Most trips include extensive idling (such as frequent driving in stop and
go traffic).
Most trips are through dusty areas.
You operate your vehicle in dusty areas or off-road frequently.
0 You frequently tow a trailer or use a carrier on top of your vehicle.
If any one of these
is true for your vehicle, then you need to change your oil
and filter every 3,000 miles (5 000 km) or 3 months - whichever comes
first.
Light Duty Emissions:
If none of them is true, change the oil and filter every 7,500 miles (1 2 500
km) or 12 months - whichever comes first.
Heavy Duty Emissions:
If none of them is true, change the oil and filter every 6,000 miles (10 000
km) or 12 months - whichever comes first.
Engine Coolant Heater
An engine coolant heater can be a big help if you have to park outside in
very cold weather, 0°F (- 18OC) or colder. If your vehicle has this option,
see “Engine Coolant Heater” in the Index.
ProCarManuals.com

Then, follow these steps:
1. Remove the filler plug.
2. Check that the lubricant level is up to the bottom of the filler plug hole.
3. If the fluid level is good, install the plug and be sure it is fully seated. If
the fluid level is low, add more fluid as described
in the next steps.
How to Add Fluid
Here’s how to add fluid. Refer to the Maintenance Schedule to determine
what kind of fluid to use. See “Recommended Fluids and Lubricants”
in the
Index.
1. Remove the filler plug.
2. Add fluid at the filler plug hole. Add only enough fluid to bring the
fluid level up
to the bottom of the filler plug hole.
3. Install the filler plug. Be sure the plug is fully seated.
Hydraulic Clutch
The hydraulic clutch linkage in your vehicle is self-adjusting. A slight
amount of play
(1/4 inch to 1/2 inch) in the pedal is normal.
6-30
ProCarManuals.com

How to Check Lubricant
P
If the level is below the bottom of the filler plug hole, you’ll need to add
some lubricant.
If the differential is at operating temperature (warm), add enough lubricant
to raise the level to the bottom of the filler plug hole.
If the differential is cold, add enough lubricant to raise the level to 1/2 inch
(I 2 mm) below the filler plug hole.
What to Use
Refer to the Maintenance Schedule to determine what kind of lubricant to
use. See “Recommended Fluids and Lubricants” in the Index.
Engine Coolant
The following explains your cooling system and how to add coolant when it
is low. If you have a problem with engine overheating, see “Engine
Overheating”
in the Index.
The proper coolant for your vehicle will:
Give freezing protection down to -34°F (-37°C).
Give boiling protection up to 262°F (128°C).
Protect against rust and corrosion.
Help keep the proper engine temperature.
Let the warning lights and gages work as they should.
What to Use
Use a mixture of one-half chi? wcmr (preferably distilled) and one-half
antifreeze that meets
“GM Specification 6038-M,” which won’t damage
aluminum parts.
You can also use a recycled coolant conforming to “GM
6-33
ProCarManuals.com