1993 CHEVROLET SUBURBAN service

I CAUTION
I 10 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, y(--
could be burned. Don’t drive with it
off, and be cr-ful working on
the engine with the air cleaner
off.
~
NOTICE I
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.
Ib remove the air cleaner filter on a gas engine, turn the wing nuts
counterclockwise. Remove the cover and change the filter.
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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. Refer to the Maintenance Schedule to determine when
to change your fluid. See “Scheduled Maintenance Services” in \
the Index.
How to Check:
Because this operation can be a little difficult, you may choose to have this
done at a General Motors dealership Sewice Department.
If you do it yourself, be sure to follow all the instructions here, or you could
get
a false reading on the dipstick.
NOTICE I
I
Too much or too little fluid can damage your transmission. Too much can
mean that some of the fluid could come out and fail
on hot engine parts,
I
starting a fire. Be sure to get an accurate reading if you check-your
transmission fluid.
Wait at least
30 minutes before checking the transmission fluid level if you
have been driving:
When outside temperatures are above 90°F (32°C).
At high speed for quite a while.
In heavy traffic-especially in hot weather.
While pulling a trailer.
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Service & Appearance Care
To get the right reading, the fluid must be at normal operating \
temperature,
which is 180°F
to 200°F (82°C to 93°C).
To check the transmission fluid hot: Get the vehicle warmed up by driving
about
15 miles (24 km) when outside temperatures are above 50°F (10°C). If
it's colder than 50°F (lO°C), drive the vehicle in 0 (3rd gear) until the engine
temperature gage moves and then remains steady for ten minutes.\
Then
follow the
hot check procedures.
To check transmission fluid cold: A cold check is made after the vehicle
has been sitting for eight hours or more with the engine
off and is used only
as a reference. Let the engine run at idle for
five minutes if outside
temperatures are 50°F (IO'C) or more. If it's colder than 50°F (1 O'C), you
may have
to idle the engine longer. A hot check must follow when fluid is
added during a cold check.
To check the fluid hot or cold:
Park your vehicle on a level place.
Place the shift lever in P (Park) with the parking brake applied.
With your foot on the brake pedal, move the shift lever throu\
gh each
gear range, pausing for about three seconds
in each range. Then,
position the shift lever in
P (Park).
Let the engine run at idle for three minutes or more.
Then, without shutting off the engine, follow these steps:
1. Flip the handle up and then pull out the dipstick and wipe it with a
clean raa or DaDer towel.
PO229
2. Push it back in all the way, wait three seconds and then pull it back out
again.
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Service & Appearance Cam
Manual Transmission Fluid
When to Check:
A good time to have it checked is when the engine oil is changed. However,
the fluid in your manual transmission doesn’t require changing.
How to Check:
Because this operation can be a little difficult, you may choose to have this
done at your dealership Service Department.
If you do it yourself, be sure to follow all the instructions here, or you could
get a false reading.
IYW I ILL
1 Too much or too little fluid can damage your transmission. Too much can 1
mean that some of the fluid could come out and fall on hot engine parts,
starting a fire. Be sure to get an accurate reading if you check your
transmission fluid,
I I
Check the fluld level only when your engine is off, the vehicle is parked on a
level place and the transmission is cool enough for you to rest your fingers
on the transmission case.
Then, follow these steps:
~~~~ K24
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.
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Service & Appearance Cave
When to Check and What to Use:
K2343
Refer to the Maintenance Schedule to determine how often you should check
the fluid level in
your clutch master cylinder reservoir and what to add. See
"Owner Checks and Services" and "Recommended Fluids and Lubrican\
ts" in
the Index.
Now to Check:
I
K2344
The proper fluid should be added if the level does not reach the bottom of
the diaphragm when it's in place in the reservoir. See the instructions on the
reservoir cap.
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Service & Appearance Care
Front Axle
When to Check and Change Lubricant:
Refer to the Maintenance Schedule to determine how often to check the
lubricant and when to change it. See “Scheduled Maintenance Services” in
the Index.
How to Check Lubricant:
PO231
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
(12 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.\

Rear Axle
When to Check and Change Lubricant:
Refer to the Maintenance Schedule to determine how often to check the
lubricant and when to change it. See “Recommended Fluids and Lubricants”
in the Index.
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Service & Appearance Care
The following explains your cooling system and how to add cool\
ant 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 258°F (125°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 clean water (preferably distilled), and antifreeze that meets
“GM Specification
6038-M,” which won’t damage aluminum parts. Also use
GM Engine Coolant Supplement (sealer) with a complete coolant change.
If
you use these, you don’t need to add anything else.
Adding only plain water to your cooling system can be dangerous.
I
Plain water, or some other liquid like alcohol, can boil before the \
proper coolant mix will. Your vehicle’s coolant warning system is set
for the proper coolant mix. With plain water or the wrong mix, your
engine could get too hot but you wouldn’t get the overheat \
warning. Your engine could catch fire and you or others could be burned. Us\
e
a 50/50 mix of clean water and a proper antifreeze.
jIi ,yo.w use an improper coolant mix, your engine .coutd overheat andi
badly damaged. The repair cost wouldn’t be covered by your warranty.’ TP~
much water in ;the mix can freeze and crack the engine, radiator, .heater
wre-ad -.other parts.
Some conditions, such as air trapped in the cooling system, can affect the
coolant level in the radiator. Check the coolant level when th\
e engine is cold
and follow the steps under “Adding Coolant” for the prope\
r way to
add
coolant.
.. .. ..
If you have to add coolant mdre than four times a year, have your dealer
check
your cooling system.
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Service & Appearance Care
Radiator Pressure Cap
I
I
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- K2515
1 NOTICE
four radiator pressure cap is a 15 psi (105 kPa) pressure-type cap and
nust be tightly installed to prevent coolant loss and possible engine
mage from overheating. Be sure the arrows on the cap line up \
with
werffow tube
on the radiator filler neck.
-m recommended.
I
Thermostat
Engine coolant temperature is controlled by a thermostat in the engine coolant
system. The thermostat stops the
flow of coolant through the radiator until the
coolant reaches a preset temperature.
When you replace
your thermostat, an AC@ thermostat is recommended.
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Service & Appearance Care
i .. c
K2694
What to Add:
Refer to the Maintenance Schedule to determine what kind of fluid to use.
See “Recommended Fluids and Lubricants” in the Index.
NOTICE I
When adding power steering fluid or making a complete fluid change,
always use the proper fluid. Failure
to use the proper fluid can cause
leaks and damage hoses
and seals.
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