Avalon lost power steering..interesting symptoms

[nomiezvr4]

So I'm trying to diagnose this friends avalon. Its a 97 with 215k on it. Lost power steering last week. The pump is still very quiet, the fluid is full and the belt is still in place.

There are no apparent huge leaks in the system either. So I put the car up in the air and while the car is off, the steering wheel is still hard to turn. Furthermore, as I'm turning the wheel, there are certain times when it gets easier to turn and others when it gets harder. So as I'm turning the wheel, when it gets harder to turn, the fluid starts to ooze out of the reservoir...???

With the car started and running on the lift, the steering feels somewhat lighter however the fluid doesn't leak out when I'm turning the wheel.

Any ideas on what it could be? I initially thought it was the PS Pump that had gone bad but the stiffness in the wheel while the car was in the air has me confused. Thanks.

Nomie

[jdmccright]

I believe your Av still uses Dexron ATF fluid in the power steering system. It should be red and clear. If it is opaque (cloudy) and brown, then it should be flushed out.

Raising the car up off the wheels removes the friction between the tires and the pavement, so the lighter steering is the result of that...the pump and rack don't have to work so hard.

Does the pump belt screech when you feel it getting hard to turn? Is it more noticeable when you turn the wheel fast? Any noises while trying to turn it past the hard spots?

[nomiezvr4]

The fluid isn't too dirty, its not the cleanest either. Do you think a flush may help? Secondly the belt is quiet no squeeks.

The steering doesn't have 'hard spots' it is hard all around. On the lift it was 'slightly' easier to turn the wheel, it acts like it has no PS period.

[jdmccright]

You report no loud whining or other noises when trying to turn the wheel. I'm going to hazard to guess that the rack's proportioning valve has gone bad or is stuck...it's what lets the fluid go from the pressurized pump line to help move the steering gear. Usually means replace or rebuild the steering rack.

I'd suggest a good flush first to see if there isn't something blocking a line first. Disconnect the fluid return line from the pump and direct it into a jug or catch pan, disconnect the cap-on-plug wires, fill the reservoir full and turn the engine over until the fluid is clear...KEEP THE RESERVOIR FILLED. After this, I'd get a shop tech to give their opinion as well. They have the equipment to properly back-flush the system to dislodge any blockages. Hope this helps!

[nomiezvr4]

UPDATE:

Changed the rack, no dice. Still no power steering. Then changed the pump and now that has finally fixed the problem. Thanks GUYS!!