I have a '92 F150 and the clutch has been acting strange. 1)At first it seemed that there wasn’t always enough (spring?) pressure to return the pedal to the top, especially while releasing it slowly, as in a three point turn. Later, the pedal would sometimes stay on the floor. I could pull it up, and with a vigorous ‘practice kick,’ get better performance out of it.
2) A regular start, like at a light, doesn’t seem to act unusual, and inter-gear shifting is normal. Never any grinding or inability to shift into gear.
3) if i put a little pressure on the pedal, it gets soft and doesn’t disengage until close to the floor, if at all. (i can use said practice kick to correct).
4) There is no leakage in the system, the fluid is full. The linkage is not perfect, but quite tight (right bushing on pedal axis- <1/32" play).
5) I tried bleeding the system by gravity (one person)- open the slave bleed valve and keep the reservoir full. No change.
I am tempted to replace the master cylinder since it’s only $41, but given the weird symptoms, cannot feel confident.
Once you get the pedal where you have some pressure behind it, try pushing it down, engine off, of course, and side stepping it a few times. Just slide your foot off the pedal and allow it to snap back up on its own. This usually will help restore a good feel to a Ford hydraulic clutch, and is a necessity with replacement of any hydraulic components to even get any clutch action out of it. If that doesn’t work, you may have a pressure plate issue. That involves doing a complete clutch job since the pressure plate comes with the clutch kit, and you will want to replace the slave cylinder while you are in there if it comes down to that.