Well, I lost all power steering when I was driving my 73 F100 last night, just stopped working out of nowhere, I’ve put fluid in it, everything holds fluid, the pump pumps the fluid fine, I’m thinking it’s steering gearbox related, I replaced the steering shaft seal and the pitman arm seal a couple months ago, previous owner replace the rag joint, and that’s all I’ve done with the power steering, it worked fine before, it does have a very small leak on the top plate of the gearbox where you adjust the worm gear, so if anyone knows what the problem is or could be or has had this problem before, help would be greatly appreciated, thanks!

 

I'm assuming you saw no evidence of fluid loss when the event happened? I'm also assuming that the seals you replaced were on the gearbox? When you say the pump pumps the fluid fine do you mean that you can see the return coming back into the pump while the engine is running? If the leak is internal, you should see less returning when the steering is moved back and forth, although that may be very slight.

 

 

Finally, was there any belt squealing when the power steering failed? This would indicate pulley bearings going bad. If not, then it sounds like the gearbox needs to be replaced. As for what brand, I'll let other members chime in. I have been fortunate in that my rebuilt unit from AZ has not leaked at all in 3 years. Good luck.