Classic/Antique Car Repair: 67 Mustang Power Steering, crank pulley, mustang gta

Question
Dick,

I read your post about the Mustang 390cid (earlier) that had the power steering pump replaced, etc.  I have a similar problem with my 67 Mustang GTA 289cid (no AC)...

I've replaced the control valve (rebuilt Cardone), all hoses, ram cylinder (new), and a genuine Ford remanufactured PS pump.  However, I didn't replace all at once, and had used F-type fluid (but not with this new pump).  When I installed new pump, I used Dexron-Mercon III fluid, without draining whole system.  I have filled system, and turn wheels side-to-side endlessly, and still have stiff steering when parked, or moving slowly.  

Is there anything to adjust on the control valve (like centering nut) that will make the PS system move smoother?

Should I drain entire system again, and refill with Dexron-Mercon III (I read your post about F-type, earlier)?

I feel that I've done everything I can think of.  I've gone through 3 pumps, and 3 control valves, and 2 ram cylinders with the same stiff results.

I love this car, and just want it to steer properly.  Can you help?

Thanks!

Rodger, Cincinnati  

Answer
These systems were not the outrageously high boost systems such as used on many modern cars, and even those on Chrysler products of that era, Ford used less boost.  In addition, your car was designed to have bias ply tires, and I'm betting you have radials on it now - they are much "stickier", especially at low speeds, so it is natural for the steering to be harder than you might be expecting.  Without comparing it with other identical cars, it's hard to know what is normal.

I think it is a good idea to get all the type "F" out of the system, so do that.  Also, make sure that your pulleys are the correct size- both the crank pulley and the PS pulley - if those have been altered, either by putting on a smaller crank pulley or a larger PS pulley, the pump output is going to be lower.  You don't mention any belt noise, so I'll assume your belt isn't slipping at idle.

I'd suggest you take the car to an old time alignment shop and have the front end checked thoroughly - if the caster and camber isn't set right, it could cause hard steering, and also you could have very high friction in one or more suspension parts, or in the steering gearbox itself.  Only a good old time front-end man is going to give you an honest opinion on it - stay away from the shops you see advertised in the newspaper or on TV - they will sell you stuff you don't need, and the "mechanic" is likely to be not too interested in really fixing your problem.  If you happen to be in the Southern California area, post a follow up to me with your e-mail address, and I can recommend two shops that I trust, who don't mind working on our old cars.

Dick