1999 CHEVROLET ASTRO fuel

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6-44 Inflation -- Tire Pressure
The Certification/Tire label, which is on the rear edge of
the driver's door, shows the correct inflation pressures
for your tires when they're cold. ªColdº means your
vehicle has been sitting for at least three hours or driven
no more than 1 mile (1.6 km).
NOTICE:
Don't let anyone tell you that underinflation or
overinflation is all right. It's not. If your tires
don't have enough air (underinflation), you can
get the following:

Too much flexing

Too much heat

Tire overloading

Bad wear

Bad handling

Bad fuel economy.
NOTICE: (Continued)
NOTICE: (Continued)
If your tires have too much air (overinflation),
you can get the following:

Unusual wear

Bad handling

Rough ride

Needless damage from road hazards.
When to Check
Check your tires once a month or more.
Don't forget your compact spare tire. It should be at
60 psi (420 kPa).
How to Check
Use a good quality pocket
-type gage to check tire
pressure. You can't tell if your tires are properly inflated
simply by looking at them. Radial tires may look
properly inflated even when they're underinflated.
Be sure to put the valve caps back on the valve stems.
They help prevent leaks by keeping out dirt
and moisture.

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6-57
Cleaning Tires
To clean your tires, use a stiff brush with a tire cleaner.
NOTICE:
When applying a tire dressing always take care to
wipe off any overspray or splash from all painted
surfaces on the body or wheels of the vehicle.
Petroleum
-based products may damage the paint
finish and tires.
Sheet Metal Damage
If your vehicle is damaged and requires sheet metal
repair or replacement, make sure the body repair shop
applies anti
-corrosion material to the parts repaired or
replaced to restore corrosion protection.
Finish Damage
Any stone chips, fractures or deep scratches in the finish
should be repaired right away. Bare metal will corrode
quickly and may develop into a major repair expense.
Minor chips and scratches can be repaired with touch
-up
materials available from your dealer or other service
outlets. Larger areas of finish damage can be corrected
in your dealer's body and paint shop.
Underbody Maintenance
Chemicals used for ice and snow removal and dust control
can collect on the underbody. If these are not removed,
accelerated corrosion (rust) can occur on the underbody
parts such as fuel lines, frame, floor pan and exhaust
system even though they have corrosion protection.
At least every spring, flush these materials from the
underbody with plain water. Clean any areas where mud
and other debris can collect. Dirt packed in closed areas
of the frame should be loosened before being flushed.
Your dealer or an underbody car washing system can do
this for you.
Chemical Paint Spotting
Some weather and atmospheric conditions can create a
chemical fallout. Airborne pollutants can fall upon and
attack painted surfaces on your vehicle. This damage can
take two forms: blotchy, ringlet
-shaped discolorations, and
small irregular dark spots etched into the paint surface.
Although no defect in the paint job causes this, GM will
repair, at no charge to the owner, the surfaces of new
vehicles damaged by this fallout condition within
12 months or 12,000 miles (20 000 km) of purchase,
whichever occurs first.

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6-64
Underhood Electrical Center
The underhood electrical center is located toward the
rear of the engine compartment on the driver's side.
Lift the hood and open the cover to gain access to this
fuse block.Feed Usage
AUX B Upfitter Battery Feed
AUX A Upfitter Accessory Feed
Relay
A/C Relay (Rear Heat and A/C)
Upfitter
-ACCY Relay
Starter Enable Relay
A/C Enable Relay
Fuel Pump Relay

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6-65
Fuse/Circuit
Breaker Usage
UPFITTER
-BATT Upfitter Battery Power Stud,
Trailer Wiring Harness
UPFITTER
-ACCY Upfitter Accessory Relay
Spare Not used
Fuse Puller*
Spare Not used
Spare Not used
ECM
-1B Fuel Pump Relay and Motor,
VCM, Oil Pressure
Switch/Sender
HORN Horn Relay and Horn
A/C COMP A/C Enable Relay and
Compressor
ATC Active Transfer Case
-L Van
ENG
-I Oxygen Sensors, Camshaft
Position Sensor, Mass Air Flow
Sensor, Evaporative Emission
Canister Purge Solenoid, Linear
EGR Valve Solenoid, VCM
EGR HI
IGN
-E A/C Enable Relay CoilFuse/Circuit
Breaker Usage
ECM
-I Fuel Injectors 1-6, Crankshaft
Position Sensor, VCM, Coil
Driver Module (EST)
LIGHTING Park Lamps Fuse, DRL Fuse,
Headlamp and Panel Dimmer
Switch
BATT Steering/Security Fuse, Courtesy
Fuse, ACSY CB, Stop/Hazard
Fuse, Auxiliary Power Fuse,
Cigarette Lighter Fuse, Radio
Battery Fuse
IGN A Starter Relay, Ignition Switch
IGN B Ignition Switch
ABS Electronic Brake Control
Module
A/C Blower Motor Resistor, Blower
Relay
RR HTR/AC Auxiliary Heater, A/C Relay
HTD MIR/RR
DEFOGRear Window Defogger
*A fuse puller is included in the underhood electrical
center. You will also find spare fuses.

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6-67
Capacities and Specifications
All capacities are approximate. English and metric
conversions are given.
Please refer to ªRecommended Fluids and Lubricantsº
in the Index for more information.
Engine Specifications
Engine ªVORTECº 4300 V6 CSFI*. . . . . . . . . . . . . .
RPO L35. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Firing Order 1
-6-5-4-3-2 . . . . . . . . . . . . . . . . . . . . . .
Horsepower 190 at 4,400 rpm. . . . . . . . . . . . . . . . . . .
Thermostat Specification 195
F (91
C) . . . . . . . . . . .
*Central Sequential Fuel Injection
Wheel Nut Torque
Base or Optional Wheel 100 lb-ft (140 N´m) . . . . . . .
Tire Pressures See ªLoading Your Vehicleº . . . . . . . .
in the Index.
Cooling System Capacity
Quantity*
without Rear HeaterQuantity*
with Rear Heater
13.5 quarts (12.8 L) 16.5 quarts (15.6 L)
After refill, the level must be checked.
*All quantities are approximate.
Crankcase Capacity
Quantity*
with Filter 4.5 quarts (4.3 L). . . . . . . . . . . . . . . . . . . .
After refill, the level must be checked. Do not overfill.
*All quantities are approximate.
Fuel Tank Capacity
Standard Tank 25.0 gallons (94.6 L). . . . . . . . . . . . . .
Transmission Capacity
Automatic Transmission
(Drain and Refill) 5.0 quarts (4.7 L). . . . . . . . . . . .

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6-69
Normal Maintenance
Replacement Parts
Replacement part numbers listed in this section are
based on the latest information available at the time of
printing, and are subject to change. If a part listed in this
manual is not the same as the part used in your vehicle
when it was built, or if you have any questions, please
contact your GM truck dealer.
Engine Oil Filter AC Type PF52. . . . . . . . . . . . . . . .
Air Cleaner AC Type A1163C. . . . . . . . . . . . . . . . . . .
Positive Crankcase Ventilation
(PCV) Valve AC Type CV769C. . . . . . . . . . . . . . . .
Spark Plugs AC Type 41
-932 . . . . . . . . . . . . . . . . . . .
Spark Plug Gap 0.060 inches (1.52 mm). . . . . . . . . .
Fuel Filter AC Type GF481. . . . . . . . . . . . . . . . . . . . .
Thermostat GM Part No. 12559051. . . . . . . . . . . . . . .
Wiper Blades (Front) Trico 22110158, Pin Type. . . . .
18 inches (45.7 cm) Length
Wiper Blade (Rear)
Trico 22154396, Pin Type
14 inches (35.5 cm) Length
Vehicle Dimensions*
Length 189.8 inches (482 cm). . . . . . . . . . . . . . . . . . .
Width 77.5 inches (196.8 cm). . . . . . . . . . . . . . . . . . .
Height 76.0 inches (193.0 cm). . . . . . . . . . . . . . . . . . .
Wheelbase 111.0 inches (281.9 cm). . . . . . . . . . . . . .
Front Tread Width 65.1 inches (165.4 cm). . . . . . . . .
Rear Tread Width 65.1 inches (165.4 cm). . . . . . . . . .
*Figures reflect base equipment only.

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7-4
Part A: Scheduled Maintenance
Services
Using Your Maintenance Schedule
We at General Motors want to help you keep your
vehicle in good working condition. But we don't know
exactly how you'll drive it. You may drive very short
distances only a few times a week. Or you may drive
long distances all the time in very hot, dusty weather.
You may use your vehicle in making deliveries. Or
you may drive it to work, to do errands or in many
other ways.
Because of all the different ways people use their
vehicles, maintenance needs vary. You may need more
frequent checks and replacements. So please read the
following and note how you drive. If you have any
questions on how to keep your vehicle in good
condition, see your dealer.
This part tells you the maintenance services you should
have done and when you should schedule them. If you
go to your dealer for your service needs, you'll know
that GM
-trained and supported service people will
perform the work using genuine GM parts.The proper fluids and lubricants to use are listed in
Part D. Make sure whoever services your vehicle uses
these. All parts should be replaced and all necessary
repairs done before you or anyone else drives
the vehicle.
These schedules are for vehicles that:

carry passengers and cargo within recommended
limits. You will find these limits on your vehicle's
Certification/Tire label. See ªLoading Your Vehicleº
in the Index.

are driven on reasonable road surfaces within legal
driving limits.

use the recommended fuel. See ªFuelº in the Index.
Selecting the Right Schedule
First you'll need to decide which of the two schedules is
right for your vehicle. Here's how to decide which
schedule to follow:

Scheduled Maintenance
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7-5
Short Trip/City Definition
Follow the Short Trip/City Scheduled Maintenance if
any one of these conditions is true for your vehicle:

Most trips are less than 5 to 10 miles (8 to 16 km).
This is particularly important when outside
temperatures are below freezing.

Most trips include extensive idling (such as frequent
driving in stop
-and-go traffic).

Most trips are through dusty areas.

You frequently tow a trailer or use a carrier on top of
your vehicle.

If the vehicle is used for delivery service, police, taxi
or other commercial application.
One of the reasons you should follow this schedule if
you operate your vehicle under any of these conditions
is that these conditions cause engine oil to break
down sooner.
Short Trip/City Intervals
Every 3,000 Miles (5 000 km): Engine Oil and Filter
Change (or 3 months, whichever occurs first). Chassis
Lubrication (or 3 months, whichever occurs first). Drive
Axle Service (or 3 months, whichever occurs first).
Every 6,000 Miles (10 000 km): Tire Rotation.
Every 15,000 Miles (25 000 km): Air Cleaner Filter
Inspection, if driving in dusty conditions. Front
Wheel Bearing Repack (2WD only) (or at each brake
relining, whichever occurs first). Automatic
Transmission Service (severe conditions only).
Every 30,000 Miles (50 000 km): Air Cleaner Filter
Replacement. Fuel Filter Replacement.
Every 50,000 Miles (83 000 km): Automatic
Transmission Service (normal conditions).
Every 60,000 Miles (100 000 km): Engine Accessory
Drive Belt Inspection. Fuel Tank, Cap and
Lines Inspection.