Having just gone through this on my SHO, the only fix I know of is to replace the pump. I got a rebuilt Cardone from Rockauto. You should also replace the pressure hose at the same time. Fear not, the job is not bad on the MTX, and my way did not require removing the motor mount like the FSM says to do.
Power Steering Pump Replacement Procedure
1. Set front of car up on 6 ton jackstands under frame rails, same as in clutch installation procedure.
2. Remove both front tires.
3. Remove battery, PS reservoir & bracket, roll dampener, pump pulley nut, accessory belts, upper timing cover, and pump pulley.
4. Remove cam position sensor and check for oil in bottom of drive housing. (Yes, check even if you are convinced your leak is PS. A leaking seal here is easy to fix now with everything opened up).
5. Position container to catch spillage and remove suction hose from pump.
6. Put 18 mm or 11/16 (tight fit) crows foot on pressure line fitting. Run long socket extension(s) toward front of engine until in the clear where a breaker bar can be used. Break fitting loose and remove. *** Although I did not need to do this, my alternative plan was to use a mini tubing cutter to cut the steel line and remove the fitting later.
7. Remove front pump mounting bolts (3) with 12mm socket.
8. Under car, place flex socket or regular 12mm socket with wobble extension on pump rear mounting bolt. Add extensions to reach all the way across the back of the engine above the exhaust manifold nearly to the transmission where there is clear space to get a breaker bar on it, or an air ratchet. Remove the rear bolt. Note it is longer than the front bolts.
9. Back up top, wiggle pump out of its mounting bracket and there is plenty of room to get it out from the top.
10. Use 18mm combo or line wrench to loosen lower pressure hose fitting on the rack by reaching in through the driver side wheel well.
11. Swap pressure switch to new hose, tighten to 5-10 ft-lb. using 9/16 crows foot. Let hose hang vertically for at least an hour before installing.
12. Reverse steps to install new pump and hose. Torque values are:
Pump bolts: 15-24 ft-lb.
Pressure hose fittings: 10-15 ft-lb (Pressure hose fittings can both be torqued with clever use of crows foot wrenches.)
Notes:
1. Be sure new pressure hose has the teflon O-rings on the fittings; they come with the hose.
2. Place plenty of rags under the PS reservoir to catch any spillage. Any fluid that runs down the inner fender will find its way into the frame, then run down and drip out near the right rear subframe bushing. That might fool you into thinking something is leaking
