I used to hear that kind of sound from our Corolla AE101, small humming effect when steering is turned full 'til the end on both sides. Turns out that the high pressure hose has been leaking oil on the crimped side. I tried to remedy it by changing the high pressure hose from Fresco which customizes crimped high pressure hose to no avail.
The problematic P/S system was gone after I bought a Toyota OE hose at 8K, changed the damaged power steering pump 16K.
Last edited by Ungas; August 24th, 2003 at 05:38 PM.