My wife started the 2000 Toyota Sienna yesterday morning (temp about 30 degrees Farenheit), warmed the engine for about 30 seconds and drove a block to the stop sign. As she made a left hand turn she was in sudden shock to feel that she had no power steering. She still was able to turn and brought the car to a stop. At that point the power steering returned and she continued her mile journey and eventual return without a problem. The power steering fluid reservoir was full. There was no puddle underneath the car. The serpentine belt was tensioned. I drove the car to the Toyota dealer and presented the problem to a front desk technician. At first he said it could be the power steering pump or rack and pinion steering assembly. When I told him that the power steering was back after she made the return he said he’d never heard of that situation. Further, he said unless the problem was showing itself when we brought the vehicle in a repairman wouldn’t be able to diagnose the situation.
If anyone has a notion to what was happening and what the fix should be I’d appreciate hearing from you.
Current tension or not, how old is the belt? How about the tensioner? What you describe would be typical of a slipping belt.
A similar problem has been noted here and at other forums lately and it is reminiscent of the “black rack” and “morning sickness” problems that plagued domestic rack and pinions in the 80s and early 90s. Although I never knew what cured the problem it seemed to disappear by the mid 90s. I replaced dozens and dozens of the rack and pinions for several years. If the power steering fluid is dark and murky that would be indicative of the earlier problem. And the most common symptom was that the steering was difficult to one direction but worked perfectly in the other direction.
I never recommend throwing parts at a problem, unless it’s a really cheap part:
Replace the serpentine belt if it’s over 5 years old. Then hope for the best.
All the above plus i would add that if the power steering fluid has not been replaced recently, you may want to have the system serviced. Losing pwr steering in a truck that size sucks
I would replace the belt, and flush out the PS hydraulic system. Also note there is usually a fluid filter screen in the PS reservoir that can become plugged up with hose particles, starving the pump…
If I remember correctly, your car has a belt just for the power steering–separate from the belt for the A/C and alternator, The PS belt is not easily seen from above and is not accessible without removing the right front wheel and spalsh guard. The PS belt also does not have an automatic tensioner, it may need to be adjusted from time to time as the belt wears and ages. I’m pretty sure your belt was slipping in the cold, and that a new belt(s) will fix it.
Rod Knox stole the words right out of my mouth…He described the issue perfectly ESP…with the symptom of having PS in one direction and not in another…the fix, when that occurs is a rack replacement…WHY? Because the Bearings in the steering shaft input portion (tube) of the rack had a faulty bearing side plate/and BB retainer ring…the retainer would allow the BB’s in the bearing to drop down into the rest of the racks input shaft area…and then it would bind up the mechanism…
I have had to replace many because of this…the last one was on my Pontiac Grand Prix GTP Supercharged… It had Power steering turning RIGHT and not turning LEFT…sounds funny I know. It was WIDELY RECALLED in GM vehicles…MANY Affected.
NOW…if your issue occurred without an audible screeching of a belt slipping (doesn’t always screech also)…this may be the Precursor to a Power Rack failure…But I think you should try new fluid…You MAY have found a droplet of frozen water in your PS fluid…OR MUCH more likely…the return line couldn’t FLOW the THICK and COLD PS fluid back to the high pressure pump FAST ENOUGH to keep pressures high and provide power assist DUE to the cold weather and that Thickening of the fluid…I would keep driving and see what happens…if the cold does this…I bet its for the reasons I listed…THAT would be good news bec you don’t want to pay for a new rack…trust me. I bet that warmer temps will make this disappear …In the meantime I would flush and replace the PS fluid to see if it helps
Blackbird
Flushing the power steering system and installing a filter often improved the situation on the old GM rack and pinions, Blackbird. It would be worth a try. I still have some in line filter adapters that held FL-1A filters which I used in that application.
Really? Hmmm…then doesn’t that indicate that a piece of debris was to blame? ANY debris in the Hydraulic system CANT be good…AT ALL… I mean…if you get a small piece of rubber say…on the wrong side of a fitting…and it blocks a tiny little orifice…then it has no way of passing it…You know?
That Grand Prix def had that Bearing retainer issue…I took it apart and confirmed it…and that was an obvious and known Physical binding of the input shaft issue…but I am also on board with any debris theory too…That can certainly do something similar but go about it in a totally different way…sure…
I have to re-read my…“Credentials Please” post to find out why some of you guys are so damn good…You included Rod, I noticed that you are on point on every issue you respond to…Nice work man
Blackbird
When the problem first appeared to me I questioned my competitors and we came to the consensus that the contaminated fluid might be causing the problem and experimented on automobiles that were in fleets that we serviced. The flush and filter seemed to often clean up the problem but less often than not. For drive up customers nothing but replacement was ever recommended by me. The problem seemed to have been caused by a combination of aging internal seals that hardened and ground into fine particles.When cold the aging seals were possibly getting near brittle??? But I have heard other explanations that seem to make sense. I stripped a few racks down that failed in that manner and could see no obvious wear or failed parts. If the rack bearing failed the end seal would fail and the rack would leak into the boot.
And thank you for the compliment Blackbird. It seems that many years working on so many different vehicles and various pieces of equipment have taught me a few lessons. You seem to have pulled a few OPs feet out of the fire, so to speak. I just wish more would get back to post the results of our advice.