Hi,

I have a 2007 4Runner at 430,000km (260,000mile).

The power steering is starting to be difficult to turn and so I’ve looked up various posts and vids to flush and completely replace the fluid.

The question I have is - does the PS fluid reservoir have a filter located at the bottom? Is it advisable to also change this plastic reservoir if it does have a filter? It costs about $80 cdn.

Anyone have experience or advice?

Thanks.

Mjl

The reservoir doesn't have a filter in it. Some have installed an inline filter when doing a fluid change, for example a Magnafine. Something unexpected that I discovered after buying my '07 is that 4th Gen 4Runners don't use power steering fluid in their PS reservoirs. Seems odd but it's true - the spec fluid is actually automatic transmission fluid - but not what you use in the 4Runner's transmission. Not weird at all, right? From the 2007 manual:
==
Check the fluid level through the reservoir. If necessary, add automatic transmission fluid DEXRON II or III.

If the vehicle has been driven around 80 km/h (50 mph) for 20 minutes (a little more in frigid temperatures), the fluid is hot (60C—80C or 140F—175F). You may also check the level when the fluid is cold (about room temperature, 10C—30C or 50F—85F) if the engine has not been run for about five hours.
==

If the fluid change doesn't help, search the forum for 4th Gen stiff steering threads. Could be an issue with the steering shaft itself.

I would focus here first as it's a common issue. Simple check, jack both front wheels off the ground and try turning the wheel with the key to on but engine off. If it's hard and notchy lock to lock then the steering shaft u-joint is most likely freezing up. It should be easy and smooth.

Thanks Bluesky and MikeinNH for your suggestions.

I have since partially changed the ps fluid. I pumped out the fluid from the reservoir and refilled. Started up engine, turned wheel left and right. Then pumped out fluid again and refilled. The old fluid was very dark, almost black and smelled burnt. I just replaced 2-3 cups. Used DEXTRON transmission fluid.

The initial results were not significant. Power steering was still heavy and then the turning action felt ”lumpy”. It was a struggle to turn, then it got momentarily better,then it was heavy turning again, etc..

Now after 4 more days of this, it back to normal. Works perfectly fine now. Problem has gone away.

The new reservoir has arrived, so I plan is to completely change out the ps fluid and switch out the old reservoir.

Will update…

UPDATE: Bad news...

Ok - so I've completely flushed the PS fluid and replaced it with DEXTRON AT fluid. The reservoir with pretty dirty and blacken inside, and since the new reservoir arrived - I decided to also replace it.

I'm totally disappointed now.

The power steering is actually hearvier and stiffer to turn the wheels. It feels "lumpy" when turning, as if it has notches in the rotation of the steering wheel. It takes a lot more effort now than ever before.

What's next? Is the U-Joint something I can "fix" or does it need to be replaced? Some threads mentioned scrapping away any rust and lubricating the joint... Would this be my next step?

Any suggestions?...

No you can't "fix" the u-joint, you can however replace the intermediate steering shaft which has a new u-joint on it.

You can spray it down thoroughly with a penetrating oil/spray and see if it frees up the steering some as a test, if that frees it up then the u-joint is definitely bad and you need to replace the shaft.

@mjlmjl : I am planning on a PS flush as well and would like to remove and clean my reservoir at same time. Did you use any write-up or manual or Youtube video or whatever to help you remove and then re-install the reservoir? Or is it so easy, i.e. just the three bolts, that a how-to was not needed?

Thanks...