I've never seen one that would hold the pressure after being "fixed",maybe someone else knows a secret way of keeping one from leaking when the seals go bad.You can always try some Lucas or Barrs Power Steering stop leak,they will swell the PS seals,the Barrs worked on my Towncar steering box seals....but the best thing is to do what SHO said...replace it,then you don't have to worry.
z