Trying to diagnose the exact problem with my 05 Chevy Uplander power steering.
Just started making that “whirring” noise yesterday while the vehicle is running, and the noise is worse (louder) when turning.
Fluid level was low, and it looked frothy or bubbly when I opened up the reservoir.
Topped off fluid today, and the noise is gone while vehicle is idling, but still makes noise when I turn the wheels.
Appears to be some fluid leaked onto what I believe is the return line hose where it goes into the pump. (it is higher up on the pump and has a rubber section with ear clamps connecting it)
So, is the return line my problem? Any further diagnosis that I should be doing to narrow it down?
Power steering hoses over time typically develop cracks and leak near the connections. It’s a high pressure hose, so it doesn’t take much degradation for it to leak. The biggest stress on the hose and pump is when the wheel is turned all the way to the steering stop, especially if it is forced by turning the steering wheel hard and holding it against the stop. Hitting the steering stop creates an unyielding force meeting an unmovable object. Nothing good will happen. The best preventive maintenance for power steering – beyond keeping the fluid level to spec – is to avoid hitting the stops as best you can, and when you hit the stop, hit it gently, and when the stop is reached, back off from the stop immediately.
I think the best course of action is to replace the broken hose. Then add fluid and bleed the system as specified by the shop manual. It is very important you use the correct type of power steering fluid btw when adding fluid to the pump. There’s various types, and the wrong type will either damage something or cause it not to work correctly. If this doesn’t fix the noise problem, you’ll have to take it to a shop for expert diagnosis and possible pump replacement.
The first thing you want to do is remove the spring clamp from the return hose and remove the hose to see if the nipple on the plastic reservior is cracked. If it is it’ll need a power steering pump with the reservoir.
The power steering pump is a vane type pump.This is pump where metal blades or vanes slide up and down in the hub of the pump as the blades/vanes pass thru the eccentric portion of the pump. When these vanes wear out or stick in the hub and the power steering fluid leaks between the vanes and the eccentric of the pump the vanes act as reeds in a wind instrument. And the pump starts making noise.