Power Steering Pump Replacement Cheat……..
Let me save you some money. The $400 stock OEM C4 pump is
nothing more than a generic GM V8 LT1 Caprice station wagon pump with a
different pressure control valve installed to provide higher effort
steering. The C4-specific valve is available separately from GM for about
$18 and it drops into the high pressure hose port. If you have a bad pump,
you might consider a $50 Pep Boys Caprice pump with a new $18 GM C4 valve.