HELLO, I HAVE A 1978 FORD F150 400M C6 4X4. WHEN I GOT THE TRUCK THE POWER STEERING DID NOT WORK AT ALL SO I PURCHASED A BRAND NEW PUMP (PLASTIC STYLE RESEVOIR W/LARGE PLASTIC CAP). I HAVE TRIED TO BLEED SYSTEM OF AIR SEVERAL TIMES AND IT HELPS FOR A LITTLE WHILE THEN NOTHING AGAIN... THEN ON ONE TRIP HOME I NOTICED I LOST ALL STEERING AGAIN SO I POPPED THE HOOD AND THE POWER STEERING CAP WAS GONE!! I WENT TO AUTOOZONE AND PICKED UP A REPLACEMENT AND BEFORE I MADE IT HOME AGAIN THE BRAND NEW CAP WAS GONE ONLY THIS TIME I FOUND THE CAP UNDER HOOD AND THE DIPSTICK ACTUALLY BROKE OFF AND IS STILL INSIDE PUMP?? WTF? I HAVE TRIED EVERYTHING EVEN INSTALLED NEW LINES. ONLY THING LEFT IS THE GEAR BOX ?? I HAVE TWO OTHER F150 TRUCKS, A 75 390FE, A 77 351M AND ALL HAVE SIMILAR PROBLEMS?? PLEASE ANY HELP WOULD BE A HUGE HELP, JAKE

 

I just posted this same question. If you figured anything out let me know. I've searched and seems you and I are the only ones to experience this?

 

1967/77's use a different P/S pump (Ford/Thompson w/a steel reservoir) than 1978 and later (Ford C-II w/a plastic reservoir).

 

Come here and read a bit of info. https://www.ford-trucks.com/forums/1...l#post17761675