1995 JEEP YJ gas mileage

MAINTENANCE SCHEDULES
INTRODUCTION
There are two maintenance schedules that show
proper service intervals for Jeep Cherokee and Jeep
Wrangler vehicles. Use the schedule that best de-
scribes the conditions the vehicle is operated under.
When mileage and time is listed, follow the interval
that occurs first.
ScheduleÐAlists all the scheduled maintenance
to be performed under normal operating conditions.
ScheduleÐBis a schedule for vehicles that are
usually operated under one or more of the following
conditions.
²Frequent short trip driving less than 5 miles (8
km).
²Frequent driving in dusty conditions.
²Trailer towing or heavy load hauling.
²Frequent long periods of engine idling.
²Sustained high speed operation.
²Desert operation.
²Frequent starting and stopping.
²Cold climate operation.
²Off road driving.
²Commercial service.
²Snow plow operation.
²More than half of vehicle operation occurs in
heavy city traffic during hot weather (above 90É F).
AT EACH STOP FOR GASOLINE
²Check engine oil level and add as required.
²Check windshield washer solvent and add as re-
quired.
ONCE A MONTH
²Check tire pressure and look for unusual tire wear
or damage.
²Check fluid levels of coolant reservoir, brake mas-
ter cylinder, power steering and transmission. Add
fluid as required.
²Check all lights and other electrical items for cor-
rect operation.
²Inspect battery and clean and tighten terminals as
required.
²Check rubber seals on each side of the radiator for
proper fit.
AT EACH OIL CHANGE
²Inspect exhaust system.
²Inspect brake hoses.
²Rotate the tires at each oil change interval shown
on ScheduleÐA: (7,500 Miles) or every other interval
shown on ScheduleÐB: (6,000 Miles).
²Check engine coolant level, hoses, and clamps.
²Lubricate 4x4 steering linkage.
²Lubricate propeller shaft universal joints and slip
spline, if equipped.After completion of off-road (4WD) operation, the
underside of the vehicle should be thoroughly in-
spected. Examine threaded fasteners for looseness.
HARSH SURFACE ENVIRONMENTS
After vehicle operation in a harsh surface environ-
ment, the following components should be inspected
and cleaned as soon as possible:
²Brake drums.
²Brake linings.
²Front wheel bearings (2WD vehicles only).
²Axle coupling joints.
This will prevent wear and/or unpredictable brake
action.
EMISSION CONTROL SYSTEM MAINTENANCE
The schedule emission maintenance listed inbold
typeon the following schedules, must be done at the
mileage specified to assure the continued proper
functioning of the emission control system. These,
and all other maintenance services included in this
manual, should be done to provide the best vehicle
performance and reliability. More frequent mainte-
nance may be needed for vehicles in severe operating
conditions such as dusty areas and very short trip
driving.
SCHEDULEÐA
7,500 MILES (12 000 KM) OR AT 6 MONTHS
²Change engine oil.
²Replace engine oil filter.
²Lubricate steering linkage (4x4).
15,000 MILES (24 000 KM) OR AT 12 MONTHS
²Change engine oil.
²Replace engine oil filter.
²Lubricate steering linkage.
22,500 MILES (36 000 KM) OR AT 18 MONTHS
²Change engine oil.
²Replace engine oil filter.
²Lubricate steering linkage (4x4).
²Inspect brake linings.
30,000 MILES (48 000 KM) OR AT 24 MONTHS
²Replace air cleaner element.
²Replace spark plugs.
²Adjust belt tension on non-automatic tensioning
drive belts.
²Change engine oil.
²Replace engine oil filter.
²Lubricate steering linkage.
²Drain and refill automatic transmission.
²Drain and refill transfer case.
0 - 4 LUBRICATION AND MAINTENANCEJ

line. You may encounter fuels containing 3 percent or
more methanol along with other alcohols called cosol-
vents.
Problems that are the result of using methanol/gas-
oline blends are not the responsibility of Chrysler
Corporation. They may not be covered by the vehicle
warranty.
MTBE/ETBE
Gasoline and MTBE (Methyl Tertiary Butyl Ether)
blends are a mixture of unleaded gasoline and up to
15 percent MTBE. Gasoline and ETBE (Ethyl Ter-
tiary Butyl Ether) are blends of gasoline and up to
17 percent ETBE. Gasoline blended with MTBE or
ETBE may be used.
CLEAN AIR GASOLINE
Many gasolines are now being blended that con-
tribute to cleaner air, especially in those areas of the
country where air pollution levels are high. These
new blends provide a cleaner burning fuel and some
are referred to asReformulated Gasoline.
In areas of the country where carbon monoxide lev-
els are high, gasolines are being treated with oxygen-
ated materials such as MTBE, ETBE and ethanol.
Chrysler Corporation supports these efforts toward
cleaner air and recommends the use of these gaso-
lines as they become available.
IGNITION CABLES, DISTRIBUTOR CAP AND
ROTOR
Inspect and test ignition cables, distributor cap and
rotor when the spark plugs are replaced. Oil and
grime should be cleaned from the ignition cables and
distributor cap to avoid possible spark plug fouling.
Mopar Foamy Engine Degreaser or equivalent is rec-
ommended for cleaning the engine compartment. For
proper service and diagnostic procedures refer to
Group 8D, Ignition System.
IGNITION TIMING
The ignition timing for 2.5L and 4.0L engines is
not adjustable. Refer to the specifications listed on
the engine Emission Control Information Label. Re-
fer to Group 25, Emission Control Systems for addi-
tional information.
SPARK PLUGS
Ignition spark plugs should be replaced at the
mileage interval described in the Lubrication and
Maintenance Schedules. Refer to the General Infor-
mation section of this group. For proper service pro-
cedures refer to Group 8D, Ignition Systems.
BATTERY
WARNING: WEAR SAFETY GLASSES, RUBBER
GLOVES AND PROTECTIVE CLOTHING WHEN HAN-DLING/SERVICING A BATTERY. THE BATTERY
ELECTROLYTE CONTAINS SULFURIC ACID AND
WILL CAUSE HARM IF IT CONTACTS SKIN, EYES
OR CLOTHING. IT WILL ALSO DAMAGE PAINTED
(AS WELL AS UN-PAINTED) SURFACES OF A VEHI-
CLE. IF SULFURIC ACID CONTACTS ANY OF
THESE, FLUSH IMMEDIATELY WITH LARGE
AMOUNTS OF WATER. IF SULFURIC ACID CON-
TACTS SKIN OR EYES, GET IMMEDIATE MEDICAL
ATTENTION. DO NOT SMOKE IN THE VICINITY OF A
BATTERY. KEEP OPEN FLAMES AND SPARKS
AWAY FROM BATTERY FILLER CAPS BECAUSE
EXPLOSIVE GAS IS ALWAYS PRESENT.
Inspect battery tray, hold down and terminal con-
nections when other under hood service is performed.
For proper diagnostic procedures refer to Group 8A,
Battery/Starting/Charging System Diagnostics. For
service and cleaning procedures refer to Group 8B,
Battery/Starter Service.
Care should be taken when disposing a bat-
tery after removal from a vehicle. Lead-acid
batteries are highly poisonous and, when indis-
criminately disposed, could create a problem
for the environment. Contact the applicable lo-
cal city or county government agency to deter-
mine where automobile (lead-acid) batteries
can be properly disposed in the local area.
RUBBER AND PLASTIC COMPONENT INSPECTION
CAUTION: Plastic hoses or wire harness covers will
melt or deform when exposed to heat from exhaust
system or engine manifolds.
Position plastic or rubber components away from
moving parts in engine compartment or under vehi-
cle, or damage will result.
Do not allow rubber engine mounts or other com-
ponents to become oil contaminated, repair cause
of oil contamination and clean area.
All rubber and plastic components should be in-
spected when engine compartment or under vehicle
service is performed. When evidence of deterioration
exists, replacement is required. To reduce deteriora-
tion of rubber components, Chrysler Corporation rec-
ommends Mopar Foamy Engine Degreaser or
equivalent be used to clean engine compartment of
oil and road grime.
EMISSION CONTROL SYSTEM
Inspect all emission control components and hoses
when other under hood service is performed. Refer to
emission system Vacuum Hose Label located on the
inside of the hood in the engine compartment and
Group 25, Emission Control Systems for proper ser-
vice procedures.
0 - 20 LUBRICATION AND MAINTENANCEJ

ABS SYSTEM CHANGES
A different master cylinder, power brake booster,
and HCU are used in the 1995 Jeep ABS system.
The master cylinder reservoir has a single filler cap
and is no longer interconnected with the HCU. The
new HCU has built-in accumulators. The pedal travel
sensor has been eliminated and a new dual dia-
phragm power brake booster is used.
BRAKE FLUID/LUBRICANTS/CLEANING SOLVENTS
Recommended fluid for all Jeep vehicles is Mopar
DOT 3 brake fluid, or an equivalent meeting SAE
J1703 and DOT 3 standards.
Use Mopar Multi Mileage grease to lubricate drum
brake pivot pins and rear brakeshoe contact points
on the support plates. Use GE 661, or Dow 111 sili-
cone grease on caliper bushings and mounting bolts.
Use fresh brake fluid or Mopar brake cleaner to
clean or flush brake system components. These are
the only cleaning materials recommended.
CAUTION: Never use gasoline, kerosene, methyl or
isopropyl alcohol, paint thinner, or any fluid con-
taining mineral oil to clean brake parts. These fluids
damage rubber cups and seals. If system contami-
nation is suspected, check the fluid for dirt, discol-
oration, or separation into distinct layers. Drain and
flush the system with new brake fluid if contamina-
tion is suspected.
JEEP BODY CODE LETTERS
The body/model identification code letters for Jeep
vehicles are as follows:²Code letters XJ: Cherokee
²Code letters YJ: Wrangler/YJ
The code letters are used throughout this group to
simplify model identification and component applica-
tion.
BRAKE SAFETY PRECAUTIONS
WARNING: ALTHOUGH FACTORY INSTALLED
BRAKELINING ON JEEP VEHICLES IS MADE FROM
ASBESTOS FREE MATERIALS, SOME AFTER MAR-
KET BRAKELINING MAY CONTAIN ASBESTOS. THIS
SHOULD BE TAKEN INTO ACCOUNT WHEN RE-
PAIRING A VEHICLE WITH PRIOR BRAKE SERVICE.
WEAR A RESPIRATOR WHEN CLEANING BRAKE
COMPONENTS AS ASBESTOS FIBERS CAN BE A
HEALTH HAZARD. NEVER CLEAN WHEEL BRAKE
COMPONENTS WITH COMPRESSED AIR. USE A
VACUUM CLEANER SPECIFICALLY DESIGNED FOR
REMOVING BRAKE DUST. IF A VACUUM CLEANER
IS NOT AVAILABLE, CLEAN THE PARTS WITH WA-
TER DAMPENED SHOP RAGS. DO NOT CREATE
DUST BY SANDING BRAKELINING. DISPOSE OF
ALL DUST AND DIRT SUSPECTED OF CONTAINING
ASBESTOS FIBERS IN SEALED BAGS OR CON-
TAINERS. FOLLOW ALL SAFETY PRACTICES REC-
OMMENDED BY THE OCCUPATIONAL SAFETY AND
HEALTH ADMINISTRATION (OSHA) AND THE ENVI-
RONMENTAL PROTECTION AGENCY (EPA), FOR
HANDLING AND DISPOSAL OF ASBESTOS.
5 - 2 BRAKESJ

Do not hone cylinder bores or polish pistons.
Replace cylinder as an assembly if bore is dam-
aged.
(8) Install bleed screw.
(9) Coat cylinder bore, pistons, cups and expander
with brake fluid and reassemble cylinder compo-
nents. Be sure piston cup lips face expander.
WHEEL CYLINDER INSTALLATION
(1) Apply small bead of silicone sealer around cyl-
inder mounting surface of support plate.
(2) Start brakeline in wheel cylinder fitting by
hand.
(3) Align and seat wheel cylinder on support plate
(Fig. 10).
(4) Install cylinder mounting bolts (Fig. 10).
Tighten bolts to 10 Nzm (90 in. lbs.) torque.(5) Tighten brakeline fitting to 15 Nzm (132 in.
lbs.) torque.
(6) Install brakeshoes. Adjust shoes to drum with
brake gauge.
(7) Install brake drums and lower vehicle.
(8) Fill master cylinder and bleed brakes.
SUPPORT PLATE REPLACEMENT
The support plate should cleaned and inspected
whenever the drum brake components are being ser-
viced.
Check the support plate for wear, or rust through
at the contact pads and replace the plate if necessary.
Be sure to lubricate the contact pads with Mopar
multi-mileage grease before shoe installation. Lubri-
cation will avoid noisy operation and shoe bind.
(1) Raise vehicle and remove wheel/tire assembly.
(2) Remove brake drum, brakeshoes, and wheel
cylinder.
(3) Remove axle shaft as described in Group 3.
(4) Remove support plate attaching nuts and re-
move support plate.
(5) Clean axle tube flange. If gasket is not used on
flange, apply thin bead of silicone adhesive/sealer to
flange.
(6) Position new support plate on axle tube flange.
(7) Apply Mopar Lock N9Seal, or Loctite 242 to
support plate attaching nuts. Then install and
tighten nuts.
(8) Apply light coat of Mopar multi-mileage grease
to contact pads of new support plate.
(9) Install wheel cylinder and brakeshoes.
(10) Adjust brakeshoes to drums. Refer to proce-
dure in this section.
(11) Bleed brakes.
(12) Install wheel and tire assembly.
(13) Adjust parking brake cable tensioner. Refer to
procedure in Parking Brake section.
(14) Lower vehicle and verify proper service brake
and parking brake operation.
BRAKE DRUM REFINISHING
Brake drums can be machined to restore the brak-
ing surface. Use a brake lathe to clean up light scor-
ing and wear.
CAUTION: Never refinish a brake drum if machining
will cause the drum to exceed maximum allowable
brake surface diameter.
Brake drums that are warped, distorted, or se-
verely tapered should be replaced. Do not refinish
drums exhibiting these conditions. Brake drums that
are heat checked or have hard spots should also be
replaced.
Fig. 8 Wheel Cylinder (9-Inch Brake)
Fig. 9 Wheel Cylinder (10-Inch Brake)
Fig. 10 Wheel Cylinder Mounting
5 - 58 DRUM BRAKESJ

For diagnostics, refer to the appropriate Powertrain
Diagnostic Procedures service manual for operation
of the DRB scan tool.
SPARK PLUGS
For spark plug removal, cleaning, gap adjustment
and installation, refer to the Component Removal/In-
stallation section of this group.
Faulty carbon and/or gas fouled plugs generally
cause hard starting, but they will clean up at higher
engine speeds. Faulty plugs can be identified in a
number of ways: poor fuel economy, power loss, de-
crease in engine speed, hard starting and, in general,
poor engine performance.
Remove the spark plugs and examine them for
burned electrodes and fouled, cracked or broken por-
celain insulators. For identification, keep plugs ar-
ranged in the order in which they were removed from
the engine. An isolated plug displaying an abnormal
condition indicates that a problem exists in the cor-
responding cylinder. Replace spark plugs at the inter-
vals recommended in the maintenance chart in
Group 0, Lubrication and Maintenance.
Spark plugs that have low mileage may be cleaned
and reused if not otherwise defective. Refer to the
following Spark Plug Condition section of this group.
CONDITION
NORMAL OPERATING
The few deposits present on the spark plug will
probably be light tan or slightly gray in color. This is
evident with most grades of commercial gasoline
(Fig. 19). There will not be evidence of electrode
burning. Gap growth will not average more than ap-
proximately 0.025 mm (.001 in) per 1600 km (1000
miles) of operation. Spark plugs that have normal
wear can usually be cleaned, have the electrodes
filed, have the gap set and then be installed.Some fuel refiners in several areas of the United
States have introduced a manganese additive (MMT)
for unleaded fuel. During combustion, fuel with MMT
causes the entire tip of the spark plug to be coated
with a rust colored deposit. This rust color can be
misdiagnosed as being caused by coolant in the com-
bustion chamber. Spark plug performance is not af-
fected by MMT deposits.
COLD FOULING/CARBON FOULING
Cold fouling is sometimes referred to as carbon
fouling. The deposits that cause cold fouling are ba-
sically carbon (Fig. 19). A dry, black deposit on one or
two plugs in a set may be caused by sticking valves
or defective spark plug cables. Cold (carbon) fouling
of the entire set of spark plugs may be caused by a
clogged air cleaner element or repeated short operat-
ing times (short trips).
WET FOULING OR GAS FOULING
A spark plug coated with excessive wet fuel or oil is
wet fouled. In older engines, worn piston rings, leak-
ing valve guide seals or excessive cylinder wear can
cause wet fouling. In new or recently overhauled en-
gines, wet fouling may occur before break-in (normal
oil control) is achieved. This condition can usually be
resolved by cleaning and reinstalling the fouled
plugs.
OIL OR ASH ENCRUSTED
If one or more spark plugs are oil or oil ash en-
crusted (Fig. 20), evaluate engine condition for the
cause of oil entry into that particular combustion
chamber.
ELECTRODE GAP BRIDGING
Electrode gap bridging may be traced to loose de-
posits in the combustion chamber. These deposits ac-
cumulate on the spark plugs during continuous stop-
and-go driving. When the engine is suddenly
Fig. 18 PCM LocationÐXJ ModelsFig. 19 Normal Operation and Cold (Carbon) Fouling
8D - 12 IGNITION SYSTEMSJ