Page 188 of 376

Downloaded from www.Manualslib.com manuals search engine Driving  On  Grades 
Reduce speed and shift to a lower gear before you start 
down 
a long  or  steep  downgrade.  If you  don’t  shift 
down,  you might have  to  use your brakes 
so much that 
they would  get hot and 
no longer work well. 
On  a long uphill  grade, shift down  and reduce 
your 
speed  to around 45 mph (70 kdh)  to reduce the 
possibility 
of engine  and transmission  overheating. 
When towing  at  high altitude 
on steep uphill  grades, 
consider  the following: Engine coolant  will  boil 
at a 
lower temperature  than at normal  altitudes. 
If you turn 
your  engine  off immediately after towing  at  high altitude 
on  steep  uphill  grades,  your vehicle  may show signs 
similar 
to engine overheating. To avoid  this,  let  the 
engine  run  while  parked  (preferably  on level  ground) 
with  the automatic  transmission 
in PARK (P) for a few 
minutes  before turning the engine off.  If  you do get  the 
overheat  warning,  see “Engine Overheating” 
in the Index. 
Parking  on  Hills 
You  really should not park your vehicle, with  a trailer 
attached, on  a hill.  If something  goes wrong, your rig 
could  start to move. People can  be injured, and both 
your vehicle  and the trailer can  be damaged. 
But  if  you  ever have to park your rig 
on a hill, here’s 
how  to do  it: 
1. ’ Apply your regular brakes, but don’t shift into 
PARK (P) yet. Then turn your wheels into the  curb 
if facing downhill or into traffic if facing uphill. 
2. Have someone  place chocks under the trailer wheels. 
3. When the  wheel chocks are in  place, release the 
regular brakes  until the chocks  absorb  the load. 
4. Re-apply  the regular brakes. Then apply your 
parking brake and then shift 
to PARK  (P). 
5. Release the regular brakes. 
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        Page 204 of 376
Downloaded from www.Manualslib.com manuals search engine Cooling System 
When you decide it’s safe to lift the hood, here’s what 
you’ll see: 
A. Radiator Pressure  Cap 
B. Coolant Recovery Tank 
C. Engine Fan(s) 
If the coolant inside the coolant recovery tank is boiling, 
don’t 
do anything else until it cools down. 
The  coolant level should  be  at 
or above the FULL 
COLD  mark. 
If it isn’t, you may have  a leak  in the 
radiator hoses, heater 
hoses, radiator, water pump  or 
somewhere  else in the cooling  system. 
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        Page 205 of 376

Downloaded from www.Manualslib.com manuals search engine A CAUTION: 
Heater  and  radiator hoses, and  other  engine 
parts,  can be very  hot.  Don’t  touch them. If  you 
do, 
you can be  burned. 
Don’t  run  the  engine if there  is 
a leak. If  you  run 
the  engine,  it could  lose 
all coolant.  That could 
cause  an engine  fire,  and  you could be  burned. 
Get  any  leak fixed before  you drive  the  vehicle. 
NOTICE: 
Engine damage  from  running  your engine 
without coolant  isn’t covered 
by your  warranty. 
If there  seems  to  be  no  leak,  start the engine  again.  See 
if  the  fan  speed  increases  when idle speed  is doubled  by 
pushing  the accelerator  pedal down. 
If it doesn’t,  your 
vehicle  needs service.  Turn 
off the engine. 
How to Add Coolant  to the Coolant 
Recovery Tank 
If  you haven’t  found a problem  yet, but the  coolant level 
isn’t at the FULL COLD mark, add a 5060 mixture of 
clean water (preferably  distilled) and DEX-COOL’” 
(orange-colored,  silicate-free)  antifreeze at the coolant 
recovery  tank.  (See  “Engine  Coolant” 
in the Index for 
more  information.) 
Adding  only plain  water  to  your cooling sy,,,m 
can be dangerous. 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.  Use 
a 50/50 mix of clean 
water  and  DEX=COOL 
TM antifreeze. 
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        Page 210 of 376
Downloaded from www.Manualslib.com manuals search engine 5. Put the cap back  on the  coolant  recovery tank, but 
leave 
the radiator  pressure  cap  off. 
I 
6. Start the engine and let it run until  you can feel the 
upper radiator  hose getting hot.  Watch out for the 
engine  fan. 
7. By this time  the coolant level  inside the radiator 
filler neck  may  be lower. If the  level 
is lower,  add 
more  of the proper  mix through the filler  neck until 
the level  reaches  the base of the  filler neck. 
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        Page 250 of 376
Downloaded from www.Manualslib.com manuals search engine NOTICE: 
If you  use an improper  coolant mix, your engine 
could overheat  and be badly damaged. The 
repair  cost wouldn't  be  covered  by your 
warranty. 
Too much  water  in  the  mix 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. 
Checking Coolant 
When your engine  is cold, the coolant level should  be at 
FULL COLD, or a little higher. 
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        Page 252 of 376

Downloaded from www.Manualslib.com manuals search engine Thermostat 
Engine coolant temperature is controlled by a thermostat 
in the engine  cooling  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. 
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. 
How To Check  Power  Steering  Fluid 
When  the engine  compartment  is  cool, 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 at the 
FULL COLD mark.  If 
necessary, add only enough fluid  to bring the 
level up to 
the mark. 
To prevent brake fluid contamination,  never  check or fill 
the power steering reservoir with the master  cylinder 
cover off. 
What to Use 
Refer  to the Maintenance  Schedule to determine  what 
kind  of fluid 
to use.  See “Recommended Fluids and 
Lubricants’’ in the Index. Always  use the proper  fluid. 
Failure 
to use  the proper  fluid can  cause leaks and 
damage  hoses and seals. 
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        Page 341 of 376

Downloaded from www.Manualslib.com manuals search engine I Long  Tripmighway  Maintenance  Schedule I- Gasoline  Engines 
97,500 Miles (162 500 km) 
0 Change engine oil and filter  (or every 
12 months, whichever occurs  first). 
An Ernissiorz Control  Service. 
0 Lubricate  chassis  components;  see  footnote ## 
(or  every  12  months,  whichever  occurs  first). 
0 Check axle fluid level  and  add fluid 
as needed. *‘1: 
0 Rotate  tires.  See  “Tire  Inspection  and 
Rotation” 
in the  Index  for  proper  rotation 
pattern  and  additional  information.  During 
tire  rotation,  check  brake  calipers  for 
freedom  of movement.  Refer  to  the 
appropriate 
GM service  manual  for  proper 
caliper  service  procedures. 
100,000 Miles (1 66 000 km) 
0 Drain, flush and  refill cooling system 
(or every 
60 months since last service, 
whichever occurs first).  See “Engine 
Coolant’’ 
in the Index for  what  to use. 
Inspect hoses. Clean radiator, condenser, 
pressure  cap and  neck. Pressure test the 
cooling system  and pressure cap. 
An Emission  Control  Service. 
0 Inspect spark  plug wires. 
An Emission  Control  Service. 
0 Replace spark plugs. 
An Emission Control Service. 
(Continued) 
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        Page 343 of 376

Downloaded from www.Manualslib.com manuals search engine Part B: Owner Checks and  Services 
Listed  below are  owner  checks  and services  which 
should  be performed  at the intervals  specified  to help 
ensure 
the safety,  dependability  and emission  control 
performance 
of your vehicle. 
Be  sure  any necessary  repairs are completed  at once. 
Whenever  any fluids  or lubricants  are added to your 
vehicle,  make sure 
they are the proper  ones, as shown 
in  Part 
D. 
At the  First 100, 1,000 and 6,000 Miles 
(160,1600 and 10 000 km) 
For  vehicles  with dual wheels, check dual  wheel nut 
torque.  For proper  torque,  see  “Wheel Nut Torque” in 
the Index. 
At Each Fuel  Fill 
Engine  Oil  Level  Check 
Check the engine  oil level and add the proper oil if 
necessary.  See “Engine  Oil” in the Index  .for 
further  details. 
Engine  Coolant  Level  Check 
Check the  engine  coolant  level and add the proper 
coolant 
mix if necessary.  See  “Engine  Coolant” in the 
Index  for further  details. 
Windshield  Washer  Fluid  Level  Check 
Check the windshield  washer fluid  level in the 
windshield  washer tank  and add 
the proper fluid if 
necessary.  See ”Windshield  Waher Fluid” in the Index 
for  further  details. 
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