1991 1999 ford explorer chilton User Manual

							Belt routing diagram-5.0L engines
Although belt routing diagrams have been included in this section, the first places you should check for proper
belt routing are the labels in your engine compartment. These should include a belt routing diagram which
may reflect changes made during a production run.
A belt routing label can usually be found under the hood
Disconnect the negative battery cable for safety. This will help assure that no one mistakenly cranks
the engine over with your hands between the pulleys.
1. 
Take a good look at the installed belt and make a note of the routing. Before removing the belt, make
sure the routing matches that of the belt routing label or one of the diagrams in this book. If for some
reason a diagram does not match (you may not have the original engine or it may have been modified,)
carefully note the changes on a piece of paper.
For tensioners equipped with a  1
/2  square hole, insert the drive end of a large breaker bar into the hole.
Use the breaker bar to pivot the tensioner away from the drive belt. For tensioners not equipped with
this hole, use the proper-sized socket and breaker bar (or a large handled wrench) on the tensioner
idler pulley center bolt to pivot the tensioner away from the belt. This will loosen the belt sufficiently
that it can be pulled off of one or more of the pulleys. It is usually easiest to carefully pull the belt out
from underneath the tensioner pulley itself.
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REMOVAL & INSTALLATION 67 
						

							Once the tension is relieved, slip the belt off the pulley then slowly release the tensioner
Once the belt is off one of the pulleys, gently pivot the tensioner back into position. DO NOT allow
the tensioner to snap back, as this could damage the tensioners internal parts.
3. 
Now finish removing the belt from the other pulleys and remove it from the engine.
4. 
To install: While referring to the proper routing diagram (which you identified earlier), begin to route the belt
over the pulleys, leaving whichever pulley you first released it from for last.
5. 
Once the belt is mostly in place, carefully pivot the tensioner and position the belt over the final
pulley. As you begin to allow the tensioner back into contact with the belt, run your hand around the
pulleys and make sure the belt is properly seated in the ribs. If not, release the tension and seat the
belt.
6. 
Once the belt is installed, take another look at all the pulleys to double check your installation.
7. 
Connect the negative battery cable, then start and run the engine to check belt operation.
8. 
Once the engine has reached normal operating temperature, turn the ignition OFFand check that the
belt tensioner arrow is within the proper adjustment range.
9. 
Timing Belts
INSPECTION
Only the 2.3L and 2.5L OHC engine uses a rubber timing belt. All other engines use a timing chain, and
no periodic inspection is required.
The 2.3L and 2.5L Ranger engine utilizes a timing belt to drive the camshaft from the crankshafts turning
motion and to maintain proper valve timing. Some manufacturers schedule periodic timing belt replacement
to assure optimum engine performance, to make sure the motorist is never stranded should the belt break (as
the engine will stop instantly) and for some (manufacturers with interference motors) to prevent the
possibility of severe internal engine damage should the belt break.
Although the 2.3L and 2.5L engine is not listed as an interference motor (it is not listed by the manufacturer as
a motor whose valves might contact the pistons if the camshaft was rotated separately from the crankshaft) the
first 2 reasons for periodic replacement still apply. Ford does not publish a replacement interval for this motor,
but most belt manufacturers recommend intervals anywhere from 45,000 miles (72,500 km) to 90,000 miles
(145,000 km). You will have to decide for yourself if the peace of mind offered by a new belt is worth it on HOW TO USE THIS BOOK
68 Timing Belts 
						

							
higher mileage engines.
But whether or not you decide to replace it, you would be wise to check it periodically to make sure it has not
become damaged or worn. Generally speaking, a severely damaged belt will show as engine performance
would drop dramatically, but a damaged belt (which could give out suddenly) may not give as much warning.
In general, any time the engine timing cover(s) is(are) removed you should inspect the belt for premature
parting, severe cracks or missing teeth. Also, an access plug is provided in the upper portion of the timing
cover so that camshaft timing can be checked without cover removal. If timing is found to be off, cover
removal and further belt inspection or replacement is necessary.
Do not bend, twist or turn the timing belt inside out. Never allow oil, water or steam to contact the belt
Check for premature parting of the belt HOW TO USE THIS BOOK
INSPECTION 69 
						

							Check if the teeth are cracked or damaged
Look for noticeable cracks or wear on the belt face
You may only have damage on one side of the belt; if so, the guide could be the culprit HOW TO USE THIS BOOK
70 INSPECTION 
						

							Foreign materials can get in between the teeth and cause damage
Inspect the timing belt for cracks, fraying, glazing or damage of any kind Damage on only one side of the timing belt may indicate a faulty guide HOW TO USE THIS BOOK
INSPECTION 71 
						

							ALWAYS replace the timing belt at the interval specified by the manufacturer
CAMSHAFT TIMING INSPECTION Locate and carefully remove the access plug from the upper portion of the timing cover.
1. 
WARNING
When turning the engine over by hand, ALWAYS rotate the crankshaft in the proper direction of rotation,
otherwise the timing belt might jump one or more teeth due to the configuration of the belt tensioner.
Turn the engine CLOCKWISE (in the normal direction of rotation) to set the engine at Top Dead
Center (TDC) of the No. 1 cylinder by aligning the O mark on the belt cover with the O mark on the
crankshaft pulley.
2. 
If no timing mark is visible through the access cover when the O marks on the crank pulley and cover
are aligned, the engine may be on No. 1 exhaust stroke and not the compression stroke (the camshaft is
180° away from No. 1 TDC). If so, the crankshaft must be rotated one full turn to bring the No. 1 piston
back to the top and the camshaft around to close the No. 1 intake and exhaust valves.
With the O marks aligned, look through the access hole in the cover to assure that the timing mark on
the camshaft sprocket aligns with the pointer on the inner belt cover. If the belt timing is incorrect, the
timing cover and belt must be removed for further inspection, possible replacement and correct
installation. For more details, please refer to Section 3 of this manual.
3. 
If timing is correct, re-install the access plug.
4. 
Hoses
INSPECTION
Upper and lower radiator hoses along with the heater hoses should be checked for deterioration, leaks and
loose hose clamps at least every 15,000 miles (24,000 km). It is also wise to check the hoses periodically in
early spring and at the beginning of the fall or winter when you are performing other maintenance. A quick
visual inspection could discover a weakened hose which might have left you stranded if it had remained
unrepaired. HOW TO USE THIS BOOK
72 CAMSHAFT TIMING INSPECTION 
						

							
Whenever you are checking the hoses, make sure the engine and cooling system are cold. Visually inspect for
cracking, rotting or collapsed hoses, and replace as necessary. Run your hand along the length of the hose. If a
weak or swollen spot is noted when squeezing the hose wall, the hose should be replaced.
The cracks developing along this hose are a result of age-related hardening
A hose clamp that is too tight can cause older hoses to separate and tear on either side of the clamp
HOW TO USE THIS BOOK
INSPECTION 73 
						

							A soft spongy hose (identifiable by the swollen section) will eventually burst and should be
replaced
Hoses are likely to deteriorate from the inside if the cooling system is not periodically flushed
REMOVAL & INSTALLATION CAUTION
Never remove the pressure cap while the engine is running, or personal injury from scalding hot coolant or
steam may result. If possible, wait until the engine has cooled to remove the pressure cap. If this is not
possible, wrap a thick cloth around the pressure cap and turn it slowly to the stop. Step back while the
pressure is released from the cooling system. When you are sure all the pressure has been released, use the
cloth to turn and remove the cap.
Remove the radiator pressure cap.
1. 
Position a clean container under the radiator and/or engine draincock or plug, then open the drain and
allow the cooling system to drain to an appropriate level. For some upper hoses, only a little coolant
must be drained. To remove hoses positioned lower on the engine, such as a lower radiator hose, the
entire cooling system must be emptied.
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74 REMOVAL & INSTALLATION 
						

							Loosen the hose clamps at each end of the hose requiring replacement. Clamps are usually either of
the spring tension type (which require pliers to squeeze the tabs and loosen) or of the screw tension
type (which require screw or hex drivers to loosen). Pull the clamps back on the hose away from the
connection.
3. 
Squeeze the spring clamp with pliers and slide it away from hose fitting Click to enlarge
Twist, pull and slide the hose off the fitting, taking care not to damage the neck of the component
from which the hose is being removed.
4. 
If the hose is stuck at the connection, do not try to insert a screwdriver or other sharp tool under the
hose end in an effort to free it, as the connection and/or hose may become damaged. Heater connections
especially may be easily damaged by such a procedure. If the hose is to be replaced, use a single-edged
razor blade to make a slice along the portion of the hose which is stuck on the connection,
perpendicular to the end of the hose. Do not cut deep so as to prevent damaging the connection. The
hose can then be peeled from the connection and discarded. HOW TO USE THIS BOOK
REMOVAL & INSTALLATION 75 
						

							Twist and pull the hose from the fitting to remove it.
Click to enlarge
Clean both hose mounting connections. Inspect the condition of the hose clamps and replace them, if
necessary.
5. 
To install: Dip the ends of the new hose into clean engine coolant to ease installation.
6. 
Slide the clamps over the replacement hose, then slide the hose ends over the connections into
position.
7. 
Position and secure the clamps at least  1
/4  in. (6.35mm) from the ends of the hose. Make sure they are
located beyond the raised bead of the connector.
8. 
Close the radiator or engine drains and properly refill the cooling system with the clean drained
engine coolant or a suitable mixture of ethylene glycol coolant and water.
9. 
If available, install a pressure tester and check for leaks. If a pressure tester is not available, run the
engine until normal operating temperature is reached (allowing the system to naturally pressurize),
then check for leaks.
10. 
CAUTION
If you are checking for leaks with the system at normal operating temperature, BE EXTREMELY CAREFUL
not to touch any moving or hot engine parts. Once temperature has been reached, shut the engine OFF, and
check for leaks around the hose fittings and connections which were removed earlier.
CV-Boots
INSPECTION
The Mountaineer and 1995-99 Explorer 4-wheel drive models use an Independent Front Suspension (IFS)
drive axle which utilizes Constant Velocity (CV) joint equipped axle half-shafts. All other 4-wheel drive
front axles are equipped with U-joints, which do not use a rubber boot to protect the joint and retain the
grease.
The CV (Constant Velocity) boots should be checked for damage each time the oil is changed and any other
time the vehicle is raised for service. These boots keep water, grime, dirt and other damaging matter from
entering the CV-joints. Any of these could cause early CV-joint failure which can be expensive to repair.
Heavy grease thrown around the inside of the front wheel(s) and on the brake caliper/drum can be an
indication of a torn boot. Thoroughly check the boots for missing clamps and tears. If the boot is damaged, it
should be replaced immediately. Please refer to Section 7 for procedures. HOW TO USE THIS BOOK
76  CV-Boots