I Have a 2001 4 Door Ford Explorer XLT 51,000 miles and im new at driving suv's and ive just noticed that when i make turns to the left even gradual turns i hear like a sort of hydraulic noise then when i straighten out the wheel the noise stops.... it happends when i turn right but its not as loud as when i turn left! Can it be the power steering pump is going?? i just bought the truck! the fluid is good and at its normal fill level! what could it be?