2001 GMC ENVOY check engine

6-20
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 GM dealership
service department.
If you do it yourself, be sure to follow all the
instructions here, or you could get a false reading.
NOTICE:
Too much or too little fluid can damage your
transmission. Too much can mean that some of
the fluid could come out and fall on hot engine
parts or exhaust system parts, starting a fire.
Be sure to get an accurate reading if you check
your transmission fluid.
Check the fluid 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:
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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6-25 What to Use
Use a mixture of one-half clean, drinkable water and
one
-half DEX-COOL
coolant which won't damage
aluminum parts. If you use this coolant mixture,
you don't need to add anything else.
CAUTION:
Adding only plain water to your cooling system
can be dangerous. Plain water, or some other
liquid like alcohol, can boil before the proper
coolant mixture will. Your vehicle's coolant
warning system is set for the proper coolant
mixture. With plain water or the wrong mixture,
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.
Use a 50/50 mixture of clean, drinkable water
and DEX
-COOL
coolant.
NOTICE:
If you use an improper coolant mixture, your
engine could overheat and be badly damaged.
The repair cost wouldn't be covered by your
warranty. Too much water in the mixture can
freeze and crack the engine, radiator, heater core
and other parts.
If you have to add coolant more than four times a year,
have your dealer check your cooling system.
NOTICE:
If you use the proper coolant, you don't have to
add extra inhibitors or additives which claim to
improve the system. These can be harmful.
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6-26 Checking Coolant
The coolant recovery tank is located near the passenger
side of the engine compartment toward the front of the
vehicle. See ªEngine Compartment Overviewº in the
Index for more information on location.The vehicle must be on a level surface. When your
engine is cold, the coolant level should be at ADD, or a
little higher. When your engine is warm, the level should
be up to FULL HOT, or a little higher.
Adding Coolant
If you need more coolant, add the proper DEX
-COOL

coolant mixture at the coolant recovery tank.
CAUTION:
Turning the radiator pressure cap when the
engine and radiator are hot can allow steam and
scalding liquids to blow out and burn you badly.
With the coolant recovery tank, you will almost
never have to add coolant at the radiator.
Never turn the radiator pressure cap
-- even a
little
-- when the engine and radiator are hot.
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6-27
Add coolant mixture at the recovery 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.
Occasionally check the coolant level in the radiator.
For information on how to add coolant to the radiator,
see ªCooling Systemº in the Index.
Radiator Pressure Cap
NOTICE:
Your radiator cap is a 15 psi (105 kPa)
pressure
-type cap and must be tightly installed to
prevent coolant loss and possible engine damage
from overheating. Be sure the arrows on the cap
line up with the overflow tube on the radiator
filler neck.
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6-28
Power Steering Fluid
When to Check Power Steering Fluid
It is not necessary to regularly check power steering fluid
unless you suspect there is a leak in the system or you hear
an unusual noise. A fluid loss in this system could indicate
a problem. Have the system inspected and repaired.
The power steering reservoir is located near the center of
the engine compartment. See ªEngine Compartment
Overviewº in the Index for more information on location.
How to Check Power Steering Fluid
Turn the key off, let the engine compartment cool down,
wipe the cap and the top of the reservoir clean, then
unscrew the cap and wipe the dipstick with a clean rag.
Replace the cap and completely tighten it. Then remove
the cap again and look at the fluid level on the dipstick.
The level should be between the ADD and FULL marks.
If necessary, add only enough fluid to bring the level up
to the proper range.
What to Use
To determine what kind of fluid to use, see
ªRecommended Fluids and Lubricantsº in the Index.
Always use the proper fluid. Failure to use the proper
fluid can cause leaks and damage hoses and seals.
Windshield Washer Fluid
What to Use
When you need windshield washer fluid, be sure to read
the manufacturer's instructions before use. If you will be
operating your vehicle in an area where the temperature
may fall below freezing, use a fluid that has sufficient
protection against freezing.
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6-30
Brakes
Brake Fluid
Your brake master cylinder reservoir is filled with
DOT
-3 brake fluid. See ªEngine Compartment
Overviewº in the Index for the location of the reservoir.
There are only two reasons why the brake fluid level in the
reservoir might go down. The first is that the brake fluid
goes down to an acceptable level during normal brake
lining wear. When new linings are put in, the fluid level goes back up.
The other reason is that fluid is leaking out of the brake
system. If it is, you should have your brake system fixed,
since a leak means that sooner or later your brakes won't
work well, or won't work at all.
So, it isn't a good idea to ªtop offº your brake fluid.
Adding brake fluid won't correct a leak. If you add fluid
when your linings are worn, then you'll have too much
fluid when you get new brake linings. You should add
(or remove) brake fluid, as necessary, only when work is
done on the brake hydraulic system.
CAUTION:
If you have too much brake fluid, it can spill on
the engine. The fluid will burn if the engine is hot
enough. You or others could be burned, and your
vehicle could be damaged. Add brake fluid only
when work is done on the brake hydraulic system.
See ªChecking Brake Fluidº in this section.
Refer to the Maintenance Schedule to determine when to
check your brake fluid. See ªPeriodic Maintenance
Inspectionsº in the Index.
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6-66 Engine Compartment Fuse Block
The fuse block is located under the hood at the
driver's side of the engine compartment. See ªEngine
Compartment Overviewº in the Index for more
information on location. Before using this fuse block
picture and chart, check to see that it matches the fuse
block in your vehicle. If the fuse block pictured here is
different than your vehicle's, use the fuse block picture
and chart located later in this section.
Remove the cover by turning the fastener
counterclockwise. To reinstall the fuse panel cover,
push in and turn the fastener clockwise.
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6-69 Engine Compartment Fuse Block
(Vehicles with HID Headlamps)
The fuse block is located under the hood at the driver's
side of the engine compartment. See ªEngine
Compartment Overviewº in the Index for more
information on location. Before using this fuse block
picture and chart, check to see that it matches the fuse
block in your vehicle. If the fuse block pictured here is
different than your vehicle's, use the fuse block picture
and chart located earlier in this section.
Remove the cover by turning the fastener
counterclockwise. To reinstall the fuse panel cover,
push in and turn the fastener clockwise.
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