Intermittent Ranger Clutch Problem

I have a 2001 Ranger P/U with a 6 cyl. and a 5 spd. manual transmission. The vehicle has had intermittent clutch problems for 4 years. It is fine when the weather is under 70 degrees. When the temperature rises, the play in the clutch (travel) increases, sometimes to the extent of not disengaging the transmission at all. When the vehicle is moving and there is excessive play in the clutch, shfting is quite difficult. This problem never occurs during cold weather and seems unreasonable in any weather for a vehicle with 30,000 miles on it.

The dealership has checked it out repeatedly and most recently flushed the fluid and replaced it. Their next suggestion was to replace the entire clutch assembly, which seems rediculous for a problem that only occurs during warm weather. Any ideas?

A couple of things come to mind. One is a bad slave cylinder, in which case I would replace the whole clutch anyway since it has to come out to get to the slave cylinder. The dealership may also have not bled the clutch out properly. When you do that, you have to readjust the slave cylinder by sidestepping the clutch a number of times. Try it on your own first. Just press the clutch pedal to the floor and let your foot slide off to the side, allowing the pedal to snap back on its own. Repeat a dozen or so times. Even with a brand new slave cylinder, no amount of bleeding will give you a good pedal feel without doing this procedure in these trucks.

The problem might be with the clutch master cylinder. I’ve seen cases where the engine heat effects the master cylinder such that the bore expands inside. This then prevents the cup seal inside the bore from completely sealing inside the bore. This then allows the hydraulic fluid to by-pass the cup seal and no hydraulic pressure can be produced to operate the slave cylinder.