hi my 92 735 has developed a intermitent pause in the stearing at low speed or when stopped the power assist isn't there,the belt is good the fluid is up (it was down 1/2 a pint)no visable leeks .it is not consistant sometimes it is when leaving the driveway when cold ,outher times when up to temp it hangs up when turning out of a parking spot it lasts for just a few seconds an then recovers ..is the pump failing? or is ther another of thos damm controll valves??..i understand the pumps are pricey..any ideas?