Parts for your 2005 Mitsubishi Lancer-Power steering pump

2005 Mitsubishi Lancer Power Steering Pump — what it does and how to look after it

Based on Mitsubishi’s own technical references, the 2005 Lancer (CS/CH series) is fitted with a hydraulic power steering system that uses a belt-driven power steering pump. This is detailed in the Mitsubishi Motors Service Manual for Lancer CS/CH, Group 37 – Steering, and reflected in the Mitsubishi ASA parts catalogue, which lists pump assemblies for 2005 Lancer variants (including common part numbers such as MR403930, depending on engine and market). The Evolution VIII/IX manuals for the same era also document a hydraulic pump layout. So, for a 2005 Mitsubishi Lancer, the power steering pump is relevant and very much part of the car’s steering assist system.

The pump’s job is to supply pressurised fluid to the steering rack so turning the wheel feels light at parking speeds while staying stable on the open road. When the pump is healthy, steering is quiet, smooth, and predictable. When it’s on the way out, drivers may notice heavy or inconsistent steering, a whine that rises with engine revs, reddish fluid leaks, or foamy fluid in the reservoir.

For ongoing care, it pays to keep an eye on the fluid and drive belt. Mitsubishi specifies an ATF meeting SP-III for most CS/CH Lancer power steering systems, using the correct fluid prevents shudder and premature wear. A quick look at the reservoir every service for level and colour (fresh fluid is translucent red, not brown or black) is a smart move. Many workshops in Aus and NZ recommend a preventive fluid exchange around 60,000–100,000 km, especially if the car sees lots of city steering or frequent tight manoeuvres.

• Common symptoms of pump trouble: whining or groaning, heavy steering at low speed, fluid leaks around the pump or pressure hose, and metal sheen in the reservoir.
• Service tips: check belt condition and tension, renew the pump’s O-rings when lines are off, and always bleed the system after any work.

Replacing a pump is a straightforward workshop job: support the vehicle safely, remove the drive belt, cap and disconnect lines, swap the pump, fit new sealing washers/O-rings, refit the belt, then refill and bleed. Bleeding is simple—wheels off the ground, fill the reservoir, turn the steering from lock-to-lock slowly, top up, then repeat with the engine idling until there’s no foaming and assist is consistent. Following the torque specs and procedures in the Mitsubishi service manual keeps it all tidy and leak-free.

FAQs

What fluid should a 2005 Lancer use in the power steering?
Mitsubishi specifies ATF meeting SP-III for most CS/CH Lancer power steering systems. Many premium fluids state SP-III compatibility. Don’t mix types—stick with one spec, and if changing brands, flush thoroughly.

How do you bleed the Lancer’s power steering after pump work?
With the front wheels off the ground, fill the reservoir, then turn the wheel slowly from lock-to-lock several times with the engine off. Top up as needed. Start the engine and repeat, watching for foaming. Once bubbles stop and assist is smooth, set the level to the “HOT” or “COLD” mark as appropriate.

When should the pump be replaced?
Many last 150,000–250,000 km. Replace if it’s noisy, leaking, can’t maintain assist, or sheds debris into the fluid. When doing the job, fit a new belt, new sealing washers/O-rings, and flush the system to protect the new pump and the rack.