2000 Ranger Excessive Clutch Pedal Free Travel

[mrm]

I recently purchased a 2000 Ranger 2.5L 5 speed. When I purchased the truck I noticed excessive clutch pedal free travel (1-1/2").

I have noticed during this winter that when the ambient temperatures are cool (~45F and below) that the clutch pedal free travel disappears and when the temperatures warm up that the free travel comes back. I have done nothing other than check the fluid level in the clutch master cylinder which is OK.

What could be the cause of the excessive free travel and why does it disappear when the ambient temperatures are cool?

Thanks for your help.

 

[RonD]

I assume you mean when you push on the clutch pedal you don't feel resistance immediately when warm but do when cold?

Things(metals and fluids) tend to expand when warmed and contract when cooled, so can't say why you would have this almost opposite effect.

I assume that there is no issue with disengaging the clutch or engaging it?

The clutch system also generates a bit of heat because of the friction when engaging disc with flywheel, so even in the cold weather the bell housing would get warmed up inside, so if the "free travel" doesn't return I wouldn't think the issue would be in that part of the system.
BUT........assuming you have the heater on inside the cab, master would warm up as well so.................

Just a thought:
There is a check valve for the reservoir, it allows fluid to flow into the system but when you push on the pedal it blocks fluid from flowing into the reservoir, this could be the problem if it is allowing a little fluid to flow into reservoir before closing, but I would think it would work better warm than cold.
It is at the bottom end of the master, so where it is coldest.

 

[mrm]

You are correct. When it's cold outside I feel resistance immediately when depressing the clutch pedal and when its warm I have free travel. Also, when it's warm outside my clutch begins to engage right after the pedal comes off the floor. When it's cold the clutch engages when the clutch pedal is much higher off the floor.

I did try one test where I removed the clutch master cylinder reservoir cap and rubber diaphragm and had someone depress and release the clutch pedal. I saw no bubbles or change in the master cylinder reservoir fluid level.

Thanks.

 

[RonD]

Was your test when it was warm or cold?

I forgot to ask earlier, is the clutch pedal returning to the full open position, but I assume you would see or feel it if it wasn't?

 

[mrm]

My test was with the engine cold and the clutch pedal is returning to all the way up every time.

 

[RonD]

Then I would wait until symptom returns and test it again that way

 

[mrm]

Update

It's been fairly warm around here the past couple of weeks and I've had lots of clutch pedal free travel. It cooled off some last night and was 42F this morning. I noticed when I got in the truck to go to work that I had the normal large amount of free travel. As I drove the truck I noticed that the free travel decreased considerably but did not totally disappear.

I wonder if the problem is simply air in the system. As ambient temperatures increase air becomes less dense so a given amount of air takes up more volume and vise versa when air temperatures drop. I would think that if I had a problem with the clutch master or slave cylinders that the symptoms would stay consistent. Any thoughts? Thanks.

 

[alwaysFlOoReD]

Bleed it and be sure. It won't hurt anything and could help.

 

[adsm08]

Ron, the reason his symptom seems to act backwards to you is because it's a hydraulic issue, not a mechanical one. Just and metals contract when cold, so do fluids. This means when it is very cold out the fluid in the system is denser, making it react to the pressure faster.


Extreme changes in pedal travel or feel on a clutch or brake system that relate to ambient temps can be a sign of a leak in the system, but more often just mean that the fluid has become water-logged and needs to be changed out.

I would start by getting fresh brake fluid in your clutch system. You can open the bleeder a full turn and just gravity bleed (or in this case flush) it adding new fluid to the reservoir before it empties. You should probably do two to three reservoirs worth.