2011-2017 Nissan Quest EHPS Power Steering Pump O-Ring Repair Kit Improved

The EHPS power steering pump in a 2011-2017 Nissan Quest may develop leaks due to a worn or damaged O-ring, leading to low fluid levels and poor steering performance. Replacing the O-ring requires careful disassembly, inspection, and reassembly to ensure a proper seal. This guide outlines the steps to replace the O-ring on the EHPS pump.

Tools and Materials Needed

• Replacement O-ring
• Power steering fluid (Nissan PSF or equivalent)
• Socket set (metric, including 10mm and 12mm)
• Wrenches (metric)
• Screwdrivers (flathead and Phillips)
• Torque wrench
• Clean rags
• Drain pan
• Pliers
• Jack and jack stands or ramps
• Safety gloves and glasses

Safety Precautions

• Work in a well-ventilated area on a level surface.
• Ensure the vehicle is securely supported on jack stands or ramps.
• Disconnect the battery to prevent electrical issues, as the EHPS pump is electro-hydraulic.
• Allow the vehicle to cool down to avoid burns from hot components.

Step-by-Step Instructions

1. Prepare the Vehicle

• Park the vehicle on a flat surface and engage the parking brake.
• Disconnect the negative battery terminal to prevent electrical shorts.
• Raise the front of the vehicle using a jack and secure it with jack stands or use ramps for access to the undercarriage.

2. Locate the EHPS Power Steering Pump

• The EHPS pump is typically located on the passenger side of the engine bay, near the front of the vehicle.
• Identify the pump by its electrical connector and hydraulic lines. It’s mounted to the engine block or a bracket.

3. Drain the Power Steering Fluid

• Place a drain pan under the pump to catch fluid.
• Disconnect the low-pressure return hose from the pump (use pliers to loosen the clamp if needed) and allow the fluid to drain into the pan.
• Plug the hose temporarily to prevent debris from entering.

4. Remove the Pump

• Disconnect the electrical connector from the EHPS pump by pressing the release tab and pulling it off.
• Remove the high-pressure line from the pump using a wrench (usually 12mm or 14mm). Be prepared for minor fluid spillage.
• Unbolt the pump from its mounting bracket (typically 2-3 bolts, 10mm or 12mm). Keep track of bolt locations.
• Carefully remove the pump from the vehicle, ensuring no damage to surrounding components.

5. Disassemble the Pump to Access the O-Ring

• Clean the pump exterior with a rag to prevent contamination.
• Identify the O-ring location, typically at the interface between the pump body and the high-pressure outlet or reservoir connection.
• Remove the bolts or screws securing the pump’s cover or fitting (refer to the service manual for exact location).
• Gently pry off the cover or fitting to expose the O-ring. Note the O-ring’s position and orientation.

6. Replace the O-Ring

• Carefully remove the old O-ring using a flathead screwdriver or plastic pick to avoid scratching the sealing surfaces.
• Inspect the O-ring groove and sealing surfaces for debris, corrosion, or damage. Clean with a lint-free cloth.
• Install the new O-ring, ensuring it seats properly in the groove. Avoid twisting or stretching the O-ring.
• Lubricate the new O-ring lightly with power steering fluid to ease installation and ensure a good seal.

7. Reassemble the Pump

• Reattach the cover or fitting, ensuring proper alignment.
• Tighten bolts or screws to the manufacturer’s specified torque (check the service manual, typically 5-10 Nm for small fittings).
• Double-check that the O-ring remains seated during reassembly.

8. Reinstall the Pump

• Position the pump back onto its mounting bracket and secure it with the original bolts, tightening to the specified torque (typically 20-30 Nm).
• Reconnect the high-pressure line, ensuring a snug fit to prevent leaks.
• Reattach the low-pressure return hose and secure the clamp.
• Reconnect the electrical connector, ensuring it clicks into place.

9. Refill and Bleed the Power Steering System

• Fill the power steering reservoir with Nissan PSF or equivalent fluid to the recommended level.
• Reconnect the battery.
• Start the engine and slowly turn the steering wheel lock-to-lock several times to bleed air from the system.
• Check the fluid level and top off as needed. Inspect for leaks around the pump and connections.

10. Test and Verify

• Lower the vehicle from the jack stands or ramps.
• Test-drive the vehicle at low speeds to ensure smooth steering operation.
• Recheck for leaks after driving and adjust fluid levels if necessary.

Tips

• Use only OEM or high-quality replacement O-rings to ensure proper fit and durability.
• If the O-ring continues to leak after replacement, inspect the pump’s sealing surfaces for damage or wear, which may require pump replacement.
• Dispose of used power steering fluid responsibly at a recycling center.

Warnings

• Do not overtighten bolts, as this can damage the pump housing or strip threads.

• • Ensure no dirt or debris enters the power steering system, as this can cause pump failure.