How to Change the Power Steering Pump on a 2002 Mercury Mountaineer

In 2002, the Mercury Mountaineer and its near-identical sibling, the Ford Explorer, underwent significant visual and mechanical changes. On the top level, the Mountaineer received an all-new 239-horsepower, 4.6-liter V-8 to replace the outgoing 5.0-liter V-8. In the base format, a new flex-fuel 4.0-liter engine put out the same 210 horsepower that the gasoline-only 4.0-liter V-6 put out the previous year. Changing the power steering pump on the base 4.0-liter engine is a straightforward task, but you need a special tool to bleed the air from the system after completing the installation.

Instructions

Removal

1

Park the Mountaineer on a level surface and allow the vehicle to sit until the engine is cool to the touch.

2

Loosen, but do not remove, the three bolts securing the power steering pulley to the power steering pump, using a ratchet and socket.

3

Draw, using a pen and paper, a diagram of the serpentine belts routing around all of the accessory pulleys.

4

Find the serpentine belt tensioner on the passengers side of the engine, just below the alternator. Place a breaker bar and socket on the bolt in the center of the tensioner pulley and rotate it counterclockwise to relive the tension from the belt. Pull the belt off all the accessory pulleys and out of the engine compartment.

5

Inspect the serpentine belt for any defects, including missing chunks or rubber, fraying or glazing. If any defects exist, replace the serpentine belt with a new one. Minor cracking across the grooved side of the belt is normal and does not indicate you need to replace it.

6

Trace the power steering reservoir-to-pump hose until you reach the pump end of it. Slide the hose clamp on the end of the hose and 3 inches up the hose, using slip-joint pliers. Position a small drain pan under the hose and pump and pull the hose from the pump with a slight twisting motion. Hold the drain pan under the hose until the fluid stops draining.

7

Follow the power steering pressure hose, the hard hose running from the steering rack to the power steering pump, until you reach its two brackets securing it to the engine block. Remove the one bolt on one bracket and two bolts from the other bracket, using a ratchet and socket.

8

Position a small drain pan under the power steering pump and loosen the fitting on the pump end of the power steering pressure hose, using a flare wrench. Remove the power steering pressure hose from the pump and pull it forward, away from the engine.

9

Pull the O-ring off the end of the power steering pressure line, using an O-ring puller or other hooked tool. Discard the O-ring.

10

Remove the three power steering-to-bracket bolts, using a ratchet and socket and pull the power steering pump from the engine compartment.

Installation

11

Apply a thin coat of new Mercon automatic transmission fluid to the new pressure hose O-ring, which comes with the replacement power steering pump. Roll the new O-ring onto the pressure hose fitting until it seats in its groove in the fitting.

12

Guide the new power steering pump onto its bracket and align the mounting holes. Hand-thread the three power steering pump-to-bracket bolts, then tighten them to 18 foot-pounds, using a torque wrench and socket.

13

Align the pressure hoses fitting with the threaded hole in the new power steering pump and hand-thread the fitting into the pump. Tighten the pressure hose fitting to 48 foot-pounds, using a torque wrench and crowfoot attachment.

14

Realign the pressure hoses brackets with their mounting holes in the engine block and thread the retaining bolts by hand. Torque the bolts to 8 foot-pounds.

15

Press the power steering reservoir-to-pump hose into the inlet on the power steering pump. Slide the hose clamp to within 1/2- inch of the end of the hose, using slip-joint pliers, to secure it.

16

Set the pulley on the new power steering pump, aligning its bolt holes with those in the pulleys drive. Tighten the pulleys retaining bolts as tight as you can get by hand.

17

Route the serpentine belt around all the pulleys on the front of the engine except the tensioner pulley, using the diagram you drew as your guide. Rotate the tensioner pulley counterclockwise with a breaker bar and socket, then align the serpentine belt with the tensioner pulley. Allow the tensioner pulley to slowly rotate counterclockwise until it holds tension on the serpentine belt.

18

Tighten the power steering pump pulley bolts to 18 foot-pounds, using a torque wrench and socket.

Filling and Bleeding the Power Steering System

19

Open the under-hood junction block, the black box just behind the battery, and find the ignition coil fuse. The ignition coil fuse is on the far driver's side of the junction block and is the second fuse from the front of the truck. In total, there are three relays and one fuse before the ignition coil fuse, moving from the front of the SUV to the rear. Pull the ignition coil fuse from the junction block.

20

Unscrew the cap from the power steering reservoir and add new Mercon automatic transmission fluid to the reservoir until the level is between the Min and Max lines on the reservoir.

21

Lift the SUV off the ground with a floor jack and slide the jack stands under the Mountaineer's frame rails. Lower the vehicle onto the jack stands.

22

Crank the Mountaineer's ignition, as if you are starting the vehicle, for about 10 seconds, as you quickly turn the steering wheel as far as you can to the right, then as far as you can to the left repeatedly. Never exceed a cranking time of 15 seconds or you may damage the starter motor.

23

Wait about one minute for the starter motor to cool, then complete step 4 once more

24

Check that the power steering fluid level in the reservoir is between the "Min" and "Max" lines. If the fluid is below the "Min" line, add Mercon fluid to bring the level to between the "Min" and "Max" marks and repeat steps 4 through 6. If the fluid is between the "Min" and "Max" marks, raise the vehicle off the jack stands, remove the stands, lower the SUV to the ground, reinstall the ignition coil fuse and proceed to the next step.

25

Select an adaptor from the vacuum pump kit D95L-7559-A, or equivalent vacuum testing kit, that fits snug on the reservoirs filler neck. Start the Mercurys engine and pump the vacuum pump until you reach between 20 and 25 inches of vacuum.

26

Allow the vehicle to idle for three minutes with the vacuum kit attached to the reservoir, then press the purge button on the vacuum pump to release the vacuum. Remove the vacuum pump and adapter from the reservoir.

27

Refill the reservoir to between the Min and Max lines.

28

Reattach the vacuum pump and adapter. Apply 20 to 25 inches of vacuum to the reservoir.

29

Turn the steering wheel to the right until it stops, then immediately release the steering wheel and leave it in that position for 30 seconds. Turn the steering wheel to the left as far as it will go, then immediately release the wheel and leave it in that position for 30 seconds. Repeat this step four times.

30

Shut the engine off. Press the purge button on the vacuum pump to release the vacuum and remove the pump and adaptor from the reservoir.

31

Recheck the fluid level in the reservoir for any bubbles. If bubbles are present, repeat the bleeding procedure from step 7. If there are no bubbles, add more fluid to the reservoir, as needed, and tighten the cap onto the reservoir.

32

Take all of the old Mercon fluid to an automotive fluid recycling center for disposal. Some auto parts stores take old fluids without charge.