Benji19912wdsr5

I would greatly appreciate any insight anyone has on this problem and thanks in advance.Power steering pump seems to be taking on air. It whines continuously and large bubbles are rising to the top in the reservoir. This started suddenly on startup one day. It gets much worse when I turn the wheel or hit the brakes. Never experienced these symptoms even after numerous brake parts and ps pump replacement. In this case, the brake system has not been interrupted and I have bleed the ps system with the truck uphill and downhill, engine running and not, tires off the ground, cap on and off. No previous problem noted except at onset symptom of sudden low fluid in reservoir after not driving the truck for about three days.
Considering that the procedure for bleeding the integrated power steering and anti-lock brake systems according to the fsm is nearly impossible without paying Toyota a ridiculous amount of money, I'm almost set on removing the brake anti-lock system altogether so I might have a chance of knowing what I'm doing while servicing the progressive power steering system.

coopster

posting in case you ever get an answer.

That ABS pump isn't leaking is it? Do you have a dash light on for it?

Benji19912wdsr5

No leaks in ABS unit. Flimsy electrical connectors corroded off in 2000 and a few months later the dash brake indicator stopped displaying. The abs/pps unit has not been a problem until a few weeks ago and seemingly for no reason. I think I will try to bleed the ps system with a vacuum pump before I replace the pump. I didn't bleed the brakes because that system has remained closed and brakes work normally.

Benji19912wdsr5

I worked with the vacuum pump bleeder for over four hours with no success. Also, while no grinding can be heard or felt from the steering gearbox, at about 180 degrees from lock left and at times right, the steering wheel becomes very difficult to turn and the pump noise increased dramatically when I continue the turn to lock. The noise goes back to it's normal "abnormal" level and my stethoscope is noisiest at the pump casing. I believe that last 180 degrees is when the mass of fine bubbles are formed in the fluid. I've ordered a pump for starts even though I know the pump should not experience any load until fully locked right or left and it should never experience any discernable load when I hit the brakes lightly. I'm discounting the possibility that the fluid might be restricted by the gearbox putting a significant load on the PS pump before it circulates to the ABS unit. I could be wrong. This is all being done with wheels off the ground.
Any advice would be appreciated.