On my way to the shooting range this morning, while coasting down the on ramp to 460, I lost my power steering. But driving on the highway it seemed to handle like normal. Long story short is that it doesn't seem to have any power steering at idle or low rpm. Sitting still, if I get on the gas in neutral it steers fine at about 1500 rpm upwards.
The belt is tight, fluid looks good, and no leaks that I can see. Apparently my gen Tacoma has had power steering pump leak issues, but that doesn't appear to be my problem. Pump also isn't making any odd noises, even when I use my Popeye arms to turn it lock to lock, pump sounds fine.
Looking at the FSM and doing a little reading, there are two valves on the pump body. An air control valve that is vacuum operated and increases the rpm from idle when the wheels are fully locked to keep the engine running. I haven't really checked its function cause it's super hard to turn my wheels lock to lock at idle right now. But I don't think it has anything to do with my problem.
The other vale is a flow control valve that I can't find much info on, but I think its sole purpose is to increase the pressure at low rpms to maintain power steering. Anybody know this to be true? Sounds like it could be my problem. Its mounted in the pump body in line with the high pressure line. And has some spring thingy that could be jammed. I hit on it with a bfh and it didn't fix anything.
I guess my question is does anyone know exactly what this thing does and how it works? I am sort of strapped for time and don't want to spend a bunch of evenings replacing random parts to find out what my issue is.
