+1 for the steering rack. If the rack leaks fluid into the rubber boots you may never see it.
Steering rack replacement
The two inner tie rod ends are usually what wears out, and at $45 each, it's better to get a replacement rack assembly since they are part of the package. The rack is about $100 + a $40 refundable core charge, which you get back when you return the old rack. Be sure to ask for the GT or high performance rack, it has fewer turns lock to lock than the standard rack.
The flex coupling for the steering shaft needs to be disconnected before you can get the rack out. You should disassemble the coupling by removing the 2 bolts that hold it together. The lower part of the coupling will then come out with the rack, and can easily be removed.
The tie rod ends can be removed with a tool that looks like a giant "pickle fork", it's less than $8, or some stores will rent/loan one. Remove the cotter pin & nut on the tie end, stick the tool between the rod end and the arm it connects and hammer away. The bigger the hammer, the easier it comes apart.
Remove the two bolts that bolt the rack assembly to the frame and then pull the rack down. Dropping the rack before attempting to remove the hydraulic lines will save you 30-45 minutes of fussing and sweating, and you’re going to have to remove them anyway. Get a catch pan to dump the fluid in when you disconnect the hydraulic lines. I replaced the rack mount bushings with some Energy Suspension urethane ones. When you re-install the rack assembly, put the rear bushings in the rack assembly and lift it into place. Then install the hydraulic lines, front bushings & washers and tighten down the nuts. Doing it this way makes room for the hydraulic lines without having them bind against the frame.
To change the tie rod ends, do them one at a time. Loosen the jam nut 1/4 turn, then unscrew the tie rod end from the rack. Turn the jam nut back 1/4 turn to return it to its original position. With the tie rod end removed, use a machinist square to measure the distance between the end of the threaded rod and the jam nut. Sit the bottom of the square against the end of the threaded rod, and the end of the blade of the square against the jam nut. Duplicate the measurement on the new rack and then install the tie rod end and tighten the jam nut. Then do the other side: the front end will need aligning, but the toe in will be close enough to the setting of the original rack to drive to the alignment shop.
Buy several extra quarts of fluid to run through the system to flush it when you change the rack. The car needs to be up on jackstands for the next step. Fill the pump up, start the car, and turn the wheels lock to lock to bleed the air out. Then stop the engine, disconnect the low pressure hose (the one that is secured with a hose clamp) and drain the pump. Re-connect, refill and do it several more times or until the fluid looks clear and not burnt or black.
Power steering pressure lines:
Each hose uses an O ring on each end to seal them. The hoses will swivel when they are installed and tightened into place. That is why there are O rings on the fittings. The O ring is the part that actually makes the pressure seal. If you slide the nut all the way back as far as it will go, you will see the O ring and the groove cut into the center section of the fitting.
Sometimes you will get some white Teflon rings with the pump or rack. The rings go on the threaded part of the fitting to reduce or prevent small leaks. They are not meant to seal the pressure part of the line or substitute for the rubber O ring. Heat the white Teflon seals in hot water and they will be easier to install. You can install the fittings without them and not have any leaks if the O rings seal good.