no power steering at idle... - Toyota Nation Forum : Toyota Car and Truck Forums

ccewbj · 08-27-2011, 07:19 PM

I changed the belt as a result of an intermittent squeal.

i now have no power assist at idle, but it powers up just fine with increased RPMs...the belt tension is good and tight. there are no sounds indicative of slippage or a pump issue.

fluid levels are good.

at idle i've pinched the pressure hose and the pump starts to squeal under ther resistance. so i think the pump is at least working...

i came across some posts about the mid staft and lubricating the u joint and while that did seem to help a little its no comparison to the steering with power...

Any experience with this?...thoughts?

Thanks!!!

ToyoGuard · 08-28-2011, 11:32 PM

Do your wheels feel like they skip when you turn them at idle? Sounds like air in the system. Try bleeding air out

ccewbj · 08-29-2011, 06:15 AM

Quote:

Originally Posted by ToyoGuard

Do your wheels feel like they skip when you turn them at idle? Sounds like air in the system. Try bleeding air out

Thanks for the reply. No there's no skipping. Just no power at all and I have to heave away until my RPMs increase and there suddenly feels the power assit kicks in. But it does feel rpm-dependent. Higher the rpm, the easier it is to turn. Very strange. Would the pressure valve play a role in this?

ToyoGuard · 08-29-2011, 05:45 PM

No, first off if you had a faulty pressure relief valve i'm sure you would have already had to replace a bursted high pressure line. The pressure relief valve kicks in when your wheel is on lock on each side it reduces the amount of pressure that builds. Honestly, I think your problem is your Flow Control valve in your pump. When your idling the pump doesn't produce the amount of pressure needed to satisfy therefore it needs a series of passages for the fluid to flow through and if your valve is clogged or stuck then your looking into a pump replacement. I could type the whole process of how the pump works, but that wont help you at all. I know it's weird how it happended right after a belt replacement, but crazy things happen in this business lol. Make sure your belt also isn't overtightended

ccewbj · 08-29-2011, 07:42 PM

Quote:

Originally Posted by ToyoGuard

No, first off if you had a faulty pressure relief valve i'm sure you would have already had to replace a bursted high pressure line. The pressure relief valve kicks in when your wheel is on lock on each side it reduces the amount of pressure that builds. Honestly, I think your problem is your Flow Control valve in your pump. When your idling the pump doesn't produce the amount of pressure needed to satisfy therefore it needs a series of passages for the fluid to flow through and if your valve is clogged or stuck then your looking into a pump replacement. I could type the whole process of how the pump works, but that wont help you at all. I know it's weird how it happended right after a belt replacement, but crazy things happen in this business lol. Make sure your belt also isn't overtightended

Thank you so much. I had mixed the two terms in my mind (pressure Relief valve vs Flow control valve)

Yeah my guess was that was the possible cause as well once I had found an image on the workings of a PS pump. Ok so not a serviceable part then.... Well I figured it would be the next thing to replace before going for broke on a new rack. I'll post up the results once I get the time to do it.

Chris

ToyoGuard · 08-29-2011, 07:57 PM

I'm almost 100% positive your Rack in fine. Replace the pump they are pretty easy on that sienna. If you do need a rack there's a how to I just wrote and posted that should work on your van. Good luck! Email me if you have any questions

ccewbj · 08-29-2011, 08:19 PM

Quote:

Originally Posted by ToyoGuard

I'm almost 100% positive your Rack in fine. Replace the pump they are pretty easy on that sienna. If you do need a rack there's a how to I just wrote and posted that should work on your van. Good luck! Email me if you have any questions

Perfect. Thank you again.

Chris

ccewbj · 09-13-2011, 08:41 AM

So thanks again....we swapped out the old pump with a used one and she's working perfectly.

I pulled apart the old one to have a look. It was pretty clean inside. I pulled out the flow control valve. It does not seem to be jammed open but I would need to understand which is the open and closed position. there is a screen filter at one end about 5 mm in diameter...perhaps that is clogged. You can't dissassemble it, but when I push the ball bearing valve (think of a grease nipple) it pushed in and the spring pushes it back closed....so I'm not sure how it was malfunctioning...perhaps the clogged filter I just mentioned. It was noted that my fluid was milky...it was likely never changed/flushed.

As a side note, if it was the flow control valve...perhaps only cleaning was required? But it is a part you can order state side...the canadian dealership does not offer it as a replaceable part....the pump in CAN is ~500-600$....a rebuilt one is ~400$...these prices are about half in US...the flow control valve state side is under 150$. Hope this helps someone.

Chris

ToyoGuard · 09-15-2011, 01:52 AM

I'm glad your back on the road. You said the fluid was milky? Keep your eye on the fluid. When fluid is milky that means a couple things.

1. Water Contimination in the Fluid
2. Worn Out Power Steering Pump (This obv you replaced it)

Flush it more often then you normally would and make sure you use World Standard transmission fluid! Don't use universal power steering fluid

ccewbj · 09-15-2011, 07:33 AM

Thanks again TG,

Yeah I suspect the fluid has never been changed.

I noted when I triend to partially reassemble the old pump for curiosity sake, the flow control valve seemed to stick. With the spring in place, it did not slide freely in the sleeve. I had to pry/pop it back out with a screw driver to get it out again. i suspect perhaps some damage from debris or similar...anyway all fixed now.

take care,

Chris