Symptoms of power steering pump going bad?

On my '90 Corolla, the power steering works. A belt has begun squealing, especially when I turn a hard right. I loosened the power steering belt a little and it squeals less. The steering is stiffer, but still comfortable. So I'm wondering if the power steering pump is going bad. The power steering fluid reservoir has the correct fluid level. Is there an objective way to test the condition of a power steering pump? Can I tell anything by removing the belt and turning the pump's pulley by hand while the engine is shut off?

Try removing the fluid from the reservoir with a 'turkey baster' and refill with Marvel mystery oil. Run this for a few hundred miles and repeat this procedure but refill with Mobil1 synthetic ATF. Suck and refill with the ATF every 1000 miled or so until the quart of ATF is gone.

Replace the belt, they have a limited lifetime.

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Originally Posted by Bruce Page

Replace the belt, they have a limited lifetime.

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+1. It is not advisable to operate with the belt loose, as other items may be operated by the same belt. Also, if it jumps the pulley it could take out your other belts, leaving you stranded or worse.

Some systems will squeal if you are hard against the stops even when they are working fine. Try turning to the stops and then back of just a bit. If the squealing stops your system is fine and you will turn 99.9 % as sharp as before.

Power steering systems usually warn about failing by getting stiffer to turn or jumpy (soft and hard as you turn the wheel).

Most power steering belts run other things like the alternator so running a loose belt is not a good idea.

What Lee said is right. Also check or just replace the belt like Bruce suggested. I bet that solves it.

If not, one other thing you might check is tie rod ends. I have seen them get dry and going bad cause a pump to squeal from working harder. If you have noticed any torque steer (pulls to one side when you "step on it", and straightens or goes the other way when you let off suddenly ) that would also indicate a tie rod end. Just dont let it get like my stepson's, I jacked his car up to check them and the drivers side fell apart when I pushed on the wheel to check for play:eek::eek:. I don't know how it was still holding, could have caused a bad wreck, especially the way he drives.

Those are the things I would start with. Belt wouldn't hurt anyway if it is at all suspect, what with winter kickin in and all.

Tie rods can be checked with nothing more than a jack. Jack one side up grab the tire and try to twist it left turn right turn. Should not have more than very minimal play. Then check the other side the same way, and while you are there feed them a shot of grease. I doubt they are at fault but have seen it happen, and all it takes is 10 minutes to check.

Hope you figure it out,
Jim

Those replies gave me helpful hints. Fortunately, on the '90 Corolla sedan the power steering belt only runs the power steering pump.

Not sure why loosening the belt should make it squeal any less - it would change the intensity of the noise if the bearing in the pulley shaft was bad.

Is anything else on this belt that could be causing the problem.


Normally the pumps leak -- I do not think we have ever had one actually stop pumping.


You may just have a bad belt -- they certainly will squeal.

If it only runs the pump how is it adjusted?

I would loosen the belt and check to see if the pulley wobbles when you try to wiggle it. If all Ok I would get a new belt and recheck. If the pump is indeed going you will want to put a new belt on it anyway.

The power steering belt on the '90 Corolla 4AFE engine is adjusted by loosening a bolt on the bracket that holds the pump and moving the pump, which pivots on another bolt.

Power steering pumps will squeal and lose their effectiveness when the bearings go out, and they are not replaceable. With the belt off try spinning it by hand and feel for excess free play or hard spots and if that's it you will need a new one. They are not all that expensive, especially if you find a rebuilt one.

If the bearings are not replaceable, how do they rebuild them? Would you get one that had old bearings in it?

The correct term is actually "remanufactured" which implies a factory rather than just a shop doing the work.

They can and do replace the bearings, they are just not available for us to replace and probably require specialized equipment to press off and on. They also replace the shaft and all seals and often do not include the reservoir. I have bought a few of them over the years and had good luck with them. Yours looks like about $95 with a $50 core charge until you return the old one at my usual places, with a 3 year/30k mile warranty.