GMC SUBURBAN 1999 Owner's Manual

7-20
Ignition Transmission Lock Check
While parked, and with the parking brake set, try to turn
the ignition key to LOCK in each shift lever position.

The key should turn to LOCK only when the shift
lever is in PARK (P).

The key should come out only in LOCK.
Parking Brake and Automatic Transmission
PARK (P) Mechanism Check
CAUTION:
When you are doing this check, your vehicle
could begin to move. You or others could be
injured and property could be damaged. Make
sure there is room in front of your vehicle in case
it begins to roll. Be ready to apply the regular
brake at once should the vehicle begin to move.
Park on a fairly steep hill, with the vehicle facing
downhill. Keeping your foot on the regular brake,
set the parking brake.

To check the parking brake's holding ability:
With the engine running and transmission in
NEUTRAL (N), slowly remove foot pressure
from the regular brake pedal. Do this until the
vehicle is held by the parking brake only.

To check the PARK (P) mechanism's holding
ability: With the engine running, shift to PARK (P).
Then release the parking brake followed by the
regular brake.
Underbody Flushing Service
At least every spring, use plain water to flush any
corrosive materials from the underbody. Take care to
clean thoroughly any areas where mud and other debris
can collect.

7-21
Part C: Periodic
Maintenance Inspections
Listed in this part are inspections and services which
should be performed at least twice a year (for instance,
each spring and fall). You should let your dealer's
service department or other qualified service center
do these jobs. Make sure any necessary repairs are
completed at once.
Proper procedures to perform these services may be
found in a service manual. See ªService and Owner
Publicationsº in the Index.
Steering and Suspension Inspection
Inspect the front and rear suspension and steering
system for damaged, loose or missing parts, signs of
wear or lack of lubrication. Inspect the power steering
lines and hoses for proper hook
-up, binding, leaks,
cracks, chafing, etc.
Exhaust System Inspection
Inspect the complete exhaust system. Inspect the body
near the exhaust system. Look for broken, damaged,
missing or out
-of-position parts as well as open seams,
holes, loose connections or other conditions which could
cause a heat build
-up in the floor pan or could let
exhaust fumes into the vehicle. See ªEngine Exhaustº
in the Index.
Engine Cooling System Inspection
Inspect the hoses and have them replaced if they are
cracked, swollen or deteriorated. Inspect all pipes,
fittings and clamps; replace as needed. Clean the
outside of the radiator and air conditioning condenser.
To help ensure proper operation, a pressure test of the
cooling system and pressure cap is recommended at
least once a year.

7-22 Throttle System Inspection
Inspect the throttle system for interference or binding,
and for damaged or missing parts. Replace parts as
needed. Replace any components that have high effort
or excessive wear. Do not lubricate accelerator and
cruise control cables.
Transfer Case (Four-Wheel Drive) Inspection
Every 12 months or at oil change intervals, check front
axle and transfer case and add lubricant when necessary.
Check vent hose at transfer case for kinks and proper
installation. More frequent lubrication may be required
on off
-road use.
Brake System Inspection
Inspect the complete system. Inspect brake lines and
hoses for proper hook
-up, binding, leaks, cracks,
chafing, etc. Inspect disc brake pads for wear and
rotors for surface condition. Inspect other brake parts,
including calipers, parking brake, etc. You may need to
have your brakes inspected more often if your driving
habits or conditions result in frequent braking.

7-23
Part D: Recommended Fluids
and Lubricants
NOTE: Fluids and lubricants identified below by name,
part number or specification may be obtained from
your dealer.
USAGE
FLUID/LUBRICANT
Engine OilEngine Oil with the American
Petroleum Institute Certified
For Gasoline Engines starburst
symbol of the proper viscosity.
To determine the preferred
viscosity for your vehicle's
engine, see ªEngine Oilº in
the Index.
Engine Coolant50/50 mixture of clean,
drinkable water and use only GM
Goodwrench

DEX-COOL

or Havoline
DEX-COOL

Coolant. See ªEngine Coolantº
in the Index.
USAGEFLUID/LUBRICANT
Hydraulic Brake
SystemDelco Supreme 11
Brake Fluid
(GM Part No. 12377967 or
equivalent DOT
-3 Brake Fluid).
Windshield
Washer SolventGM Optikleen
Washer
Solvent (GM Part No. 1051515)
or equivalent.
Hydraulic Clutch
SystemHydraulic Clutch Fluid
(GM Part No. 12345347 or
equivalent DOT
-3 Brake Fluid).
Power Steering
SystemGM Power Steering Fluid
(GM Part No. 1052884
- 1 pint,
1050017
- 1 quart, or equivalent).
Automatic
TransmissionDEXRON
-III Automatic
Transmission Fluid.
Key Lock
CylindersMulti-Purpose Lubricant,
Superlube
(GM Part
No. 12346241 or equivalent).

7-24
USAGEFLUID/LUBRICANT
Floor Shift
LinkageLubriplate
Lubricant Aerosol
(GM Part No. 12346293 or
equivalent) or lubricant meeting
requirements of NLGI # 2
Category LB or GC
-LB.
Chassis
LubricationChassis Lubricant (GM Part
No. 12377985 or equivalent) or
lubricant meeting requirements
of NLGI # 2, Category LB
or GC
-LB.
Front AxleSAE 80W-90 Axle Lubricant
(GM Part No. 1052271
or equivalent).
Rear AxleSAE 75W-90 Synthetic Axle
Lubricant (GM Part No. 12378261)
or equivalent meeting GM
Specification 9986115.
USAGEFLUID/LUBRICANT
Automatic
Transfer CaseAutomatic Transfer Case Fluid
(GM Part No. 12378396).
Front Axle
Propshaft Spline
or One
-Piece
Propshaft Spline
(Two
-Wheel
Drive with
Auto. Trans.)
Spline Lubricant, Special Lubricant
(GM Part No. 12345879) or
lubricant meeting requirements of
GM 9985830.
Rear Driveline
Center SplineChassis Lubricant (GM Part
No. 12377985 or equivalent) or
lubricant meeting requirements
of NLGI # 2, Category LB
or GC
-LB.
Hood Latch
Assembly,
Secondary Latch,
Pivots, Spring
Anchor and
Release PawlLubriplate
Lubricant Aerosol
(GM Part No. 12346293 or
equivalent) or lubricant meeting
requirements of NLGI # 2,
Category LB or GC
-LB.

7-25
USAGEFLUID/LUBRICANT
Hood HingesMulti-Purpose Lubricant,
Superlube
(GM Part
No. 12346241 or equivalent).
Body Door Hinge
Pins, Liftgate
Hinge and
Linkage, Folding
Seats and Fuel
Door HingeMulti-Purpose Lubricant,
Superlube
(GM Part
No. 12346241 or equivalent).
USAGEFLUID/LUBRICANT
Weatherstrip
ConditioningDielectric Silicone Grease
(GM Part No. 12345579
or equivalent).
Weatherstrip
SqueaksSynthetic Grease with Teflon,
Superlube
(GM Part
No. 12371287 or equivalent).

7-26
Part E: Maintenance Record
After the scheduled services are performed, record the
date, odometer reading and who performed the service
in the boxes provided after the maintenance interval.Any additional information from ªOwner Checks and
Servicesº or ªPeriodic Maintenanceº can be added on
the following record pages. Also, you should retain all
maintenance receipts. Your owner information portfolio
is a convenient place to store them.
Maintenance Record
DATEODOMETER
READINGSERVICED BYMAINTENANCE PERFORMED

7-27
Maintenance Record
DATEODOMETER
READINGSERVICED BYMAINTENANCE PERFORMED

7-28
Maintenance Record
DATEODOMETER
READINGSERVICED BYMAINTENANCE PERFORMED

8-
8-1
Section 8 Customer Assistance Information
Here you will find out how to contact GMC if you need assistance. This section also tells you how to obtain service
publications and how to report any safety defects.
8
-2 Customer Satisfaction Procedure
8
-4 Customer Assistance for Text Telephone
(TTY) Users
8
-4 Customer Assistance Offices
8
-5 GM Mobility Program for Persons
with Disabilities
8
-6 Roadside Assistance
8
-7 Canadian Roadside Assistance
8
-8 Courtesy Transportation8
-9 Warranty Information
8
-10 Reporting Safety Defects to the United
States Government
8
-10 Reporting Safety Defects to the
Canadian Government
8
-11 Reporting Safety Defects to General Motors
8
-11 Ordering Owner Publications in Canada