How to Change the Power Steering Pump on a 1993 Lexus GS300

In 1993, Toyota Motor Co.'s luxury automaker, Lexus, released an all-new sports sedan, the GS 300. This shapely sedan, which the rest of the world knew as a Toyota Aristo, came standard with a 220-horsepower, 3.0-liter in-line six-cylinder engine and power steering. The power steering pump is responsible for creating the hydraulic pressure the steering rack requires to turn the front wheels with ease. Replacing the power steering pump will vary slightly, depending on the replacement pump you buy. If the pump comes with a pulley and reservoir, there is no need to transfer any parts from the old pump. If the pump comes without those components, you need to transfer them from the old pump to the new one.

Instructions

Removal

1

Connect a memory saver to the GS 300 in accordance to the memory savers instruction manual.

2

Loosen the negative battery cable end, using a combination wrench, and pull it from the battery. Loosen the positive battery cable end and pull the cable from the battery. Remove the nut and bolt securing the battery tie-down bar, using a combination wrench, and remove the bar. Lift the battery from the vehicle.

3

Draw a diagram of how the serpentine belt routes over all of the accessory pulleys on the front of the engine. This will aid in reinstalling the belt correctly.

4

Find the belt tensioner assembly just above the crankshaft pulley. Position a breaker bar and socket on the bolt in the center of the tensioner pulley and rotate the pulley clockwise to relieve tension from the belt. Pull the belt from the pulleys and out of the engine compartment. Allow the tensioner to slowly rotate back to its resting position.

5

Inspect the serpentine belt for any defects, including missing chunks of rubber, fraying or glazing. Small cracks along the grooved side of the belt are normal and are not a defect. Replace the belt if any defects exist.

6

Slide a drain pan under the vehicle so it is below the power steering pump to catch the fluid as you remove the hoses.

7

Hold the power steering pressure hoses inlet fitting on the power steering pump with a 24 mm open-end wrench and loosen the pressure hoses union bolt, using a ratchet and socket. Remove the union bolt, power steering pressure hose and two brass washers from the power steering pump. Discard the washers.

8

Slide the hose clamp on the end of the power steering pump return hose about 3 inches up the hose, using slip-joint pliers. Pull the return hose from the power steering pump and let all of the fluid drain from the power steering pump reservoir and return hose into the drain pan.

9

Remove the two power steering pump-to-bracket bolts, using a ratchet and socket, and lift the power steering pump from its bracket and out of the engine compartment. You can access these bolts through the holes cut out in the power steering pump pulley by rotating the pulley until a hole aligns with each bolt.

10

Remove the cap from the power steering pump reservoir and pour the remaining fluid about an inch of fluid into the drain pan.

Transferring Components

11

Mount the power steering pump in a soft-jawed vise to hold it in place.

12

Hold the power steering pump pulley still with a variable pin wrench set Toyota special tool No. 09960-10010 by inserting the wrenchs pins into the holes in the pulley. Remove the nut from the power steering pumps driveshaft, using a ratchet and socket, and pull the pulley from the pumps axle.

13

Remove the three bolts securing the reservoir to the pump, using a ratchet and socket. Pull the reservoir upward sharply to remove it from the pump.

14

Pull the O-ring from the reservoir, using an O-ring pick or similar hooked tool. Apply a thin coat of new Dexron-II transmission fluid to the replacement O-ring, which comes with the new pump, and roll it onto the reservoirs outlet nipple until it seats in the groove on the nipple.

15

Remove the old pump from the vise and mount the new pump in the vise.

16

Pull all the plastic plugs from the new pump's orifices. Align the outlet nipple on the power steering pump reservoir with its inlet on the new pump. Press downward on the reservoir until the reservoirs nipple seats in the pumps inlet orifice. Hand-thread the three reservoir-retaining bolts, then toque the rear two bolts to 12 foot-pounds and the front bolt to 9 foot-pounds, using a torque wrench and socket.

17

Guide the pulley onto the new pumps drive shaft and hand-thread the pulleys retaining nut. Hold the pulley still with a variable pin wrench set and torque the nut to 32 foot-pounds.

18

Remove the pump from the vise.

19

Lower the new power steering pump into the bracket and hand-tighten the pumps mounting bolts, using the holes cut out in the pulley for access. Torque the power steering bolts to 43 foot-pounds, using a torque wrench and socket.

20

Slide a new brass washer -- two new washers come with the new pump -- onto the pressure hoses union bolt and insert the bolt through the end of the power steering pressure hose. Slide the second washer onto the union bolt.

21

Guide the power steering pressure hose onto the power steering pump so the stopper the tab protruding from the end of the pressure hose contacts the flat on the pumps body. Hand-thread the pressure hoses union bolt, then torque it to 36 foot-pounds while holding the union fitting on the new pump still with a 24 mm open-end wrench.

22

Press the return hose onto its inlet on the new pump and slide the hose clamp to within 1/2 inch of the end of the return hose, using slip-joint pliers.

23

Route the serpentine belt over all of the accessory pulleys except the tensioner pulley, using the diagram you drew as your guide. Rotate the tensioner pulley counterclockwise and align the belt with the pulley. Allow the tensioner pulley to rotate toward the belt slowly until it holds tension on the belt.

24

Reinstall the battery onto its tray and set the tie-down bar back into place on the battery. Snug the tie-down bars nut and bolt with a combination wrench.

25

Press the positive battery cable onto the positive battery terminal and tighten the cable ends pinch bolt with a combination wrench. Reconnect the negative cable end to the negative battery terminal and snug its pinch bolt. Disconnect the memory saver.

Filling and Bleeding the System

26

Unscrew the cap from the power steering pump reservoir and add new Dexron-II transmission fluid to the reservoir in quarter-pint increments, checking the level at each increment, until the fluid level reaches the Cold section on the cap-mounted dipstick.

27

Start the engine and let it idle. Turn the steering wheel as far as you can to the left and hold it there for two or three seconds. Turn the steering wheel as far as you can to the right and hold it there for two to three seconds. Repeat this step four times.

28

Check the fluid in the reservoir. If it is cloudy or has foam on it, allow it to settle. Check the fluid level in the reservoir, using the cap-mounted dipstick, and measure the amount of fluid on the stick with a ruler.

29

Shut the engine off. Wipe the old fluid off the dipstick with a clean, lint-free cloth and recheck the fluid level with the engine off. Measure the amount of fluid on the dipstick and compare it to the first measurement. If the difference is greater than 0.20 inches, proceed to the next step. If the difference is 0.20 inches or less, reinstall the cap, as the system requires no more bleeding.

30

Remove the return hose from the reservoir by sliding its hose clamp about three inches up the hose, using slip-joint pliers, and pulling the hose from the reservoir with a slight twisting motion. Allow the fluid to drain from the reservoir and return hose into the drain pan below.

31

Seal the return hoses inlet on the reservoir with a rubber plug. Fill the power steering reservoir with fresh Dexron-II automatic transmission fluid.

32

Place the free end of the return hose into a clean and clear 1-quart or larger container. Start the engine and instruct an assistant to hold the engine speed at 1,000 rpm.

33

Watch for fluid to start flowing from the return hose and listen for sputtering as the fluid comes from the hose. Shut the engine off and check the fluid level in the reservoir. Refill the reservoir with Dexron-II, as needed. Repeat this step until fluid flows from the return hose smoothly, without sputtering.

34

Reconnect the return hose and position its hose clamp within 1/2 inch of the end of the hose, using slip-joint pliers.

35

Bring the power steering fluid level back to within the Cold range on the power steering reservoirs cap-mounted dipstick.

36

Take any old fluid to a used automotive fluid recycling center. Some auto parts stores take old fluids without charge.