If it is leaking it can be resealed. if it does not work a reman or used one will do the trick. They are not hard to change so a DIY project is in order. Use the money you save for some other goodies or pay the tow truck to haul off that Tempo:lol:
There is a kit available from the dealer with all the seals in the pump. As long as it has not been run out of fluid and is not noisey and the power assist is good then resealing it is the way to go. You should be able to find proceedure info in a toyota service manual.
The squealing noise isn't a belt is it. could also be a bad bearing in the idler.
If it's just a leak you're trying to fix I've found that AutoRX works quite will. I've tried synthetic power steering fluid a couple of times but it quickly developed leaks. Typical stop-leak products did not help, used in synthetic PS or Dexron ATF fluid. Only going back to Dexron III ATF and adding a couple ounces of AutoRX solved the problem.
Told you I'd keep you updated. Local mechanic replaced power steering belt (and others while he was at it). Belts were under parts warranty since they had been replaced less than 2 years ago. Noise gone, cost $25.00.