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Power Steering Pump Replacement
 
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Pelican Technical Article:

Power Steering Pump Replacement

Nick Czerula

Time:

4 hours4 hrs

Tab:

$300

Talent:

*****

Tools:

Set of sockets E10, E12, 7mm, wrenches 22mm, screwdrivers

Applicable Models:

Mercedes-Benz E320 (2003-09)
Mercedes-Benz E500 (2003-06)
Mercedes-Benz E55 AMG (2003-06)

Parts Required:

Power steering pump, power steering fluid, power steering hose clamp, serpentine belts, high-pressure line copper sealing gaskets

Hot Tip:

Work with a cool engine

Performance Gain:

Quite power steering pump, remedy power steering leaks

Complementary Modification:

Change power steering fluid reservoir

One of the major accessories that run off of the accessory drive belt is the power steering pump. The power steering pump is unique on your vehicle because, of all the components in the car, the power steering pump produces the most pressure of any system. It is not unusual for a power steering pump to produce 1,000 to 2,000 psi while under load from the vehicle turning.

The power steering pump pressurizes hydraulic fluid to provide assist to the driver, when turning the steering wheel. The pressurized fluid travels from the pump to the power steering rack, then through two lines to each side of a piston in the steering rack. When the driver moves the steering wheel to one side to turn, the hydraulic pressure helps to push the rack in the direction desired.

When a power steering pump begins to fail, it will emit a groan when steering from side to side or you will notice increased steering effort. Of course, the pump could leak also, but a noisy weak pump is most common. If you loose function of your power steering or it takes a greatly increased effort to steer your vehicle, remove the drive belt and inspect the power steering pump shaft. If you can slide the pulley out of the power steering pump, the shaft is broken. You will have to replace the power steering pump.

Remember that your car may have been serviced before and had parts replaced with different size fasteners used in the replacement. The sizes of the nuts and bolts we give may be different from what you have so be prepared with different size sockets and wrenches.

Protect your eyes, hands and body from fluids, dust and debris while working on your vehicle. If you're working with the electrical system, disconnect the battery before beginning. Always catch fluids in appropriate containers and properly dispose of any fluid waste. Recycle parts, packaging and fluids when possible. Never work on your vehicle if you feel the task is beyond your ability.

Our vehicle may vary slightly from yours as models do change and evolve, as they grow older. If something seems different, let us know and share your info to help other users. Do you have questions or want to add to the article? Leave a comment below. When leaving a comment, please leave your vehicle information.

In this article, I'll go over the steps involved with replacing and bleeding the power steering pump.

The power steering pump on W211 models with a 6-cylinder engine is mounted to the lower left side of the engine (red arrow).
Figure 1

The power steering pump on W211 models with a 6-cylinder engine is mounted to the lower left side of the engine (red arrow). To access is, begin by removing the engine covers.

Working at the engine cover (red arrow), pull off the two front air duct hoses (green arrows).
Figure 2

Working at the engine cover (red arrow), pull off the two front air duct hoses (green arrows).

To detach the ducts, pull them straight off the engine cover/air filter housing.
Figure 3

To detach the ducts, pull them straight off the engine cover/air filter housing. Then pull the front of the duct out of the radiator support and remove them from the engine. Repeat this step for each duct.

Lift up and remove the front engine cover.
Figure 4

Lift up and remove the front engine cover.

Then, pull the engine cover/air filter housing straight up to remove it.
Figure 5

Then, pull the engine cover/air filter housing straight up to remove it. Four metal clips that grab onto rubber mounts hold on the cover. The front two are shown (red arrows). The rear of the cover has two as well. Once detached, remove the engine cover/air filter housing from the engine.

Locate the accessory drive belt tensioner (red arrow) on the left side of the engine.
Figure 6

Locate the accessory drive belt tensioner (red arrow) on the left side of the engine.

Using a ratchet with a long handle and a 17mm socket, rotate the drive belt tensioner counterclockwise to release tension and slide the belt off the pulleys (red arrow).
Figure 7

Using a ratchet with a long handle and a 17mm socket, rotate the drive belt tensioner counterclockwise to release tension and slide the belt off the pulleys (red arrow). Remove the engine drive belt. See our tech article on engine drive belt replacing for detailed information.

Use a suction pump.
Figure 8

Use a suction pump. Suck the power steering fluid out of the reservoir.

Working at the left corner of the engine, below the power steering reservoir (green arrow), using a 22 mm wrench, remove the PS pump high-pressure line (blue arrow).
Figure 9

Working at the left corner of the engine, below the power steering reservoir (green arrow), using a 22 mm wrench, remove the PS pump high-pressure line (blue arrow). The high-pressure steering line is sealed with two copper gaskets. Be sure to remove them from the line and pump. Then replace with new when reinstalling. Next, using a Phillips head screwdriver or 7mm nut driver, remove the power steering return hose clamp. Then remove the return hose from the pump. Remove the hose slowly. Have the oil pan ready to catch the PS fluid. Note: If needed, remove or move the coolant reservoir aside. I find removing the mounting fastener, and then slightly lifting it and leaving it an angle makes enough room to work. See our tech article on coolant reservoir replacing.

Next, you are going to remove the rear fasteners and the ground strap.
Figure 10

Next, you are going to remove the rear fasteners and the ground strap. This photo shows the back of the pump, as viewed from the left side of the engine. The yellow arrow points to the front of the valve cover. The red arrow points to the power steering reservoir. Start by removing the ground strap, remove the E12 fastener (blue arrows) then lay the strap aside. Next, remove the two E12 power steering pump mounting fasteners (green arrows). I like to break the rear fasteners free. I then remove them by hand. Note the length of these bolts, as the rear bolts are shorter than the front bolts.

Using a ratchet with a long handle and a 17mm socket, rotate the drive belt tensioner counterclockwise to release tension and allow access to the lower power steering pump (blue arrow) E12 fastener (red arrow).
Figure 11

Using a ratchet with a long handle and a 17mm socket, rotate the drive belt tensioner counterclockwise to release tension and allow access to the lower power steering pump (blue arrow) E12 fastener (red arrow). Hold the tensioner in place while you remove the fastener. Once out, release the tensioner.

Directly above the fastener you just removed (green arrow) is the final E12 pump fastener (red arrow).
Figure 12

Directly above the fastener you just removed (green arrow) is the final E12 pump fastener (red arrow). Remove it.

Next, remove the E10 power steering reservoir fastener (red arrow).
Figure 13

Next, remove the E10 power steering reservoir fastener (red arrow). Then slide the power steering pump toward the radiator to remove the reservoir from the oil filter housing (green arrow).

Next, remove the pump from the engine and drain the remaining fluid into a suitable container.
Figure 14

Next, remove the pump from the engine and drain the remaining fluid into a suitable container.

Place the pump on a bench.
Figure 15

Place the pump on a bench. Use a flathead screwdriver and remove the reservoir retaining clip (red arrow). Then, slide the reservoir off the power steering pump. Transfer the reservoir over to the new pump.

Then lower the new power steering pump into the engine compartment.
Figure 16

Then lower the new power steering pump into the engine compartment. Slide the reservoir into the notch in the oil filter housing (red arrow). Install the power steering pump fasteners and tighten. Then reassemble the remaining items in the reverse order of removal. Once complete, fill and bleed the power steering system. Before starting the engine, fill the power steering reservoir with clean fluid to the MAX level on the dipstick. Start the engine and turn the steering wheel fully left and right three times. Turn the engine off, check the fluid level and add fluid until it reaches MAX on the dipstick. When full, fluid should be clear and foam free. Foam or bubbles is a sign of air in the system.

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Comments and Suggestions:
Lucas Comments: Hello,

For replacing the power steering rack, how many bottles of power steering fluid shall I prepare for such replacement?

Thanks.

Lucas
February 27, 2017
  Followup from the Pelican Staff: 6-8 I believe will cover the replacement and a brief flush. - Casey at Pelican Parts  
Alexis Barkly Comments: This info is very much important in power steering service. Good job.
January 29, 2016
  Followup from the Pelican Staff: Thanks for the feedback. We appreciate it.
- Nick at Pelican Parts
 
callie Comments: My husband is having some trouble replacing his power steering. This guide looks really helpful.
July 31, 2015
  Followup from the Pelican Staff: Thanks for the feedback. Glad we could help.
- Nick at Pelican Parts
 

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Page last updated: Wed 5/24/2017 02:49:46 AM