2004 JEEP GRAND CHEROKEE pressure

WARNING!
²Use only refrigerants and compressor lubricants
approved by the manufacturer for your air condi-
tioning system. Some unapproved refrigerants are
flammable and can explode, injuring you. Other
unapproved refrigerants or lubricants can cause
the system to fail, requiring costly repairs.
²The air conditioning system contains refrigerant
under high pressure. To avoid risk of personal
injury or damage to the system, adding refrigerant
or any repair requiring lines to be disconnected
should be done by an experienced repairman.
Refrigerant Recovery and Recycling
R-134a Air Conditioning Refrigerant is a hydrofluorocar-
bon (HFC) that is endorsed by the Environmental Pro-
tection Agency and is an ozone-saving product. How-
ever, the manufacturer recommends that air conditioning
service be performed by dealers or other service facilities
using recovery and recycling equipment.
NOTE:Air Conditioning systems found to be contami-
nated with A/C System Sealers, Stop Leak Products, Seal
Conditioners, Compressor Oil, or Refrigerants not ap-
proved by the manufacturer, voids the warranty for the
Air Conditioning system.
Power Steering Fluid Check
Checking the power steering fluid level at a defined
service interval is not required. The fluid should only be
checked if a leak is suspected, abnormal noises are
266 MAINTAINING YOUR VEHICLE

WARNING!
Commercially available windshield washer solvents
are flammable. They could ignite and burn you. Care
must be exercised when filling or working around
the washer solution.
Exhaust System
The best protection against carbon monoxide entry into
the vehicle body is a properly maintained engine exhaust
system.
If you notice a change in the sound of the exhaust system;
or if the exhaust fumes can be detected inside the vehicle;
or when the underside or rear of the vehicle is damaged;
have an authorized technician inspect the complete ex-
haust system and adjacent body areas for broken, dam-
aged, deteriorated, or mispositioned parts. Open seams
or loose connections could permit exhaust fumes to seepinto the passenger compartment. In addition, inspect the
exhaust system each time the vehicle is raised for lubri-
cation or oil change. Replace as required.
Cooling System
WARNING!
You or others can be badly burned by hot coolant or
steam from your radiator. If you see or hear steam
coming from under the hood, don't open the hood
until the radiator has had time to cool. Never try to
open a cooling system pressure cap when the radia-
tor or coolant bottle is hot.
Coolant Checks
Check coolant protection every 12 months (before the
onset of freezing weather, where applicable). If coolant is
MAINTAINING YOUR VEHICLE 269
7

Cooling System Pressure Cap
The cap must be fully tightened to prevent loss of
coolant, and to insure that coolant will return to the
radiator from the coolant reserve tank.
The cap should be inspected and cleaned if there is any
accumulation of foreign material on the sealing surfaces.
WARNING!
The warning words DO NOT OPEN HOT on the
cooling system pressure cap are a safety precaution.
Never add coolant when the engine is overheated.
Do not loosen or remove the cap to cool an over-
heated engine. Heat causes pressure to build up in
the cooling system. To prevent scalding or injury, do
not remove the pressure cap while the system is hot
or under pressure.
Coolant Level
Check the coolant level at least once a month or more
often in hot weather. Check the level when the engine is
at normal operating temperature. Check the coolant level
only in the coolant recovery bottle. The coolant level
must be between the FULL and the ADD mark on the
bottle.
272 MAINTAINING YOUR VEHICLE

See your authorized dealer if the coolant level drops
quickly.
Points To Remember
NOTE:When the vehicle is stopped after a few miles of
operation, you may observe vapor coming from the front
of the engine compartment. This is normally a result of
moisture from rain, snow, or high humidity accumulat-
ing on the radiator and being vaporized when the
thermostat opens, allowing hot coolant to enter the
radiator.
If an examination of your engine compartment shows no
evidence of radiator or hose leaks, the vehicle may be
safely driven. The vapor will soon dissipate.
²Do not overfill the coolant bottle.
²Check coolant freeze point in the system.
²If frequent coolant additions are required, or if the
level in the recovery bottle does not drop when the
engine cools, the cooling system should be pressure
tested for leaks.
²Maintain coolant concentration at 50% ethylene glycol
antifreeze (minimum) in water for proper corrosion
protection of your engine that contains aluminum
components.
²Make sure that the radiator and coolant bottle hoses
are not kinked or obstructed.
²Do not change the thermostat for summer or winter
operation. If replacement is ever necessary, install
ONLY the correct type thermostat. Other designs may
result in unsatisfactory cooling performance, poor gas
mileage, and increased emissions.
MAINTAINING YOUR VEHICLE 273
7

cuts, abrasion, and excessive swelling suggest deteriora-
tion of the rubber. Particular attention should be made to
examining those hose surfaces nearest to high heat
sources, such as the exhaust manifold.
Inspect all hose clamps and couplings to make sure they
are secure and no leaks are present.
NOTE:Often fluids such as oil, power steering fluid,
and brake fluid are used during assembly plant opera-
tions to ease the assembly of hoses to couplings. There-
fore, oil wetness at the hose-coupling area is not neces-
sarily an indication of leakage. Actual dripping of hot
fluid when systems are under pressure (during vehicle
operation) should be noted before hose is replaced based
on leakage.NOTE:Inspection of brake hoses should be done when-
ever the brake system is serviced and every engine oil
change.
WARNING!
Worn brake hoses can burst and cause brake failure.
You could have an accident. If you see any signs of
cracking, scuffing, or worn spots, have the brake
hoses replaced immediately.
MAINTAINING YOUR VEHICLE 275
7

Once a Month
²Check the tire pressure and look for unusual wear or
damage.
²Inspect the battery and clean and tighten the terminals
as required.
²Check the fluid levels of the coolant reservoir, brake
master cylinder, and transmission, and add as needed.
²Check all lights and all other electrical items for correct
operation.At Each Oil Change
²Change the engine oil filter.
²Inspect the exhaust system.
²Inspect brake hoses.
²Check the coolant level, hoses, and clamps.
²Rotate the tires at each oil change interval shown on
Schedule ªAº 6,000 miles (10 000 km) or every other
interval shown on Schedule ªBº 6,000 miles (10 000
km).
²After completion of off-road operation, the underside
of the vehicle should be thoroughly inspected. Exam-
ine threaded fasteners for looseness.
298 MAINTENANCE SCHEDULES
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Adding Washer Fluid..................... 171
Adjustable Pedals........................ 84
Air Cleaner, Engine...................... 264
Air Conditioner Maintenance............... 265
Air Conditioning........................ 164
Air Conditioning Refrigerant............... 266
Air Conditioning System.................. 164
Air Filter.............................. 264
Air Pressure, Tires....................... 212
Airbag................................ 35
Airbag Deployment....................... 42
Airbag Light.......................44,52,129
Airbag Maintenance....................... 43
Alarm................................ 23
Alarm, Panic............................ 21
Alarm System........................... 23
Alignment and Balance................... 217
Alterations/Modifications, Vehicle............. 8
Antenna, Satellite Radio................... 155Antifreeze (Engine Coolant)................ 291
Anti-Lock Brake System................... 197
Anti-Lock Warning Light.................. 133
Anti-Theft System........................ 23
Appearance Care........................ 281
Arming Theft System...................... 23
Automatic Dimming Mirror................. 60
Automatic Door Locks..................... 19
Automatic Headlights..................... 77
Automatic Temperature Control............. 167
Automatic Transmission................179,277
Adding Fluid......................278,279
Fluid and Filter Changes................. 277
Fluid Level Check...................277,278
Fluid Type........................... 277
Gear Ranges.......................... 181
Overdrive........................... 182
Shifting............................. 179
Special Additives...................... 280
328 INDEX

Cassette Tape and Player Maintenance......... 162
Cassette Tape Player...................143,147
Catalytic Converter...................... 261
Caution, Exhaust Gas...................... 51
CD Changer......................140,150,156
CD Player....................136,139,143,149
CD Player Maintenance................... 163
Cellular Phone.......................... 164
Center Lap Belts......................... 33
Chains, Tire............................ 220
Chart, Tire Sizing........................ 204
Check Engine Light...................... 130
Checks, Safety.........................52,53
Child Restraint.......................... 44
Child Restraint Tether Anchors............... 47
Child Safety Locks........................ 18
Climate Control......................... 164
Clock................................ 135
Compact Disc Maintenance................. 163Compact Spare Tire...................... 241
Compass...........................101,104
Compass Calibration..................... 104
Compass Variance....................... 105
Computer, Trip/Travel.................... 101
Console, Overhead....................... 89
Contract, Service........................ 320
Converter, Catalytic...................... 261
Cooling System......................... 269
Adding Coolant (Antifreeze).............. 271
Coolant Capacity...................... 291
Coolant Level......................... 272
Disposal of Used Coolant................ 270
Drain, Flush, and Refill.................. 270
Inspection........................... 269
Points to Remember.................... 273
Pressure Cap......................... 272
Radiator Cap......................... 272
Selection of Coolant..................270,291
330 INDEX