Diagnosing And Correcting Power Steering Leaks
Most common places:
P/S reservoir and hoses/ On a 16V, undo the two 10mm bolts holding the reservoir to the fender and pull it gently out to access its two hose clamps on its supply and return lines. Tighten them up. Recheck them each oil change (why they are called minor services, not just oil changes). If you once pull the reservoir back like this, you can reposition the clamps so you can get at them without removing the reservoir next time. Clean the reservoir off well while it is pulled back. The older white plastic ones can leak where the nipples for the hoses attach to it. A bit of silicon on a clean reservoir and without fluid overnight will usually fix the leaks from the seam here. Be gentle with the nipples and the reservoir, they get brittle with age and heat. If a nipple gets broken, it is usually better to replace the reservoir than try and repair it. The fluid will attack most adhesives and the nipple will fail again, maybe this time when it is not at all convenient to have to try and fix it.
P/S return hose clamp on the bottom of the pump. Again, check it every oil change and retighten if needed.
P/S supply hose (high pressure) between pump and rack. These, like the a/c hoses tend to have their rubber shrink and the crimp then gets loose. Nothing to do if it gets bad enough but replace the hose, about $50. I have seen these seep and get no worse for years. Rare to see one blow.
Fitting/valve where the pressure line attaches to the ps pump. Tighten it up. The line is 16 mm, the fitting into the pump is 22 mm. These commonly get loose and seep. The line has an o ring on it that may get cut or shrink.
Lines into rack at its pinion housing. Same deal with loosening and orings. Do not overtorque though, you can crack the rack. A cracked rack case necessitates relacing the rack.
Rack at the pinion seal (where steering column attaches). Replace the rack if a last ditch effort of one of the stop leak products doesn't slow it down. Racks with lifetime warranties are available for less than $150 with a sleeve in the pinion housing to prevent morning sickness due to wear there and in the spool valve.
Rack at its end seals. If leaking here, the boots on the end of the rack will fill with fluid. Remedy same as above. Internal parts of the rack and the labor and special tools needed to get to them quickly make replacement with a rebuilt rack more economical.
Pump at its pulley seal. Replace the pump. This is rare and when we do see one (usually one that has been run dry frequently) we use a salvage yard pump because it is not a common problem, at least around here. For $50, its not worth trying to rebuild a leaker with a scored shaft anyway. BTDT.
Cooling loop in pressure line, where it attaches to the bracket for the pump going into the pump. Like any line, bending will crack it and I have seen a lot of these cracked by people using the loop as a lever to tension the belt. Saab wants $60+ for this short loop. Getting a salvage yard to take one off and not destroy it is almost as hard as fitting rings to a running engine.
Preventative maintenance:
Tighten the clamps and lines with every oil change. Flush the fluid every major service. Use the GM P/S fluid, not ATF. Remove the reservoir and clean the magnet as well as possible with brakeclean and let it dry thoroughly before putting it back on. Keep as much dirt as possible off the pinion seal. 9000s have a protective boot over theirs, but 900s are open to road dirt and grime and engine oil leaks. Replace the tie rod boots if they get torn to keep dirt from the end seals. Keep the fluid level happy until leaks are repaired.
You can flush the system with an assistant to man the ignition key and steering wheel while you keep watch of the fluid level and condition. Be real careful not to run the system dry of fluid. Remove the return line from the pump (8V) or reservoir (16V) and route it to a oil catch pan. Plug the end of the pump or reservoir from which you removed the return hose. Have a supply of P/S fluid handy. Start the carand keep pouring in new fluid while the car runs. After a couple of quarts go through, turn the wheel to the right and run a couple of more quarts through. Then turn to the left ansd run a couple of quarts through. If the fluid has not been flushed in a while, it may take a lot of fluid to clean up the system. I would not run more than a half a case through it however. Just repeat the process again at the next oil change and subsequent changes until you get a reasonably clean system. Newer 9000s have a filter in the reservoir and it really helps keep their fluid clean. After you get your clean you might consider installing a in line filter in the return line to keep as much particulates as possible filtered out. Just be sure you don't let the filter clog up or you could damage the pump and/or rack.
Remove the belt if no fluid is available, or the leak is fast. This will prevent damage to the pump until you can take care of the leak. Steering effort, especially at low speeds will be greatly increased.