'97 F150 - clutch won't engage when hot

It was hot yesterday, and I was going home from a buddies place. I stopped at the store (after a 30-40 min. drive) to pick something up. When I came back out I couldn't get my truck into gear (manual tranny). Shifter worked fine, but acted like it was in neutral. I topped up the master cylinder with brake fluid and was able to crawl home at 15mph.

I go out this morning while the temps are cooler to start checking it out and it's acting normal again. Goes right into gear and moves.

At first I was thinking a bad slave cylinder, but now I'm thinking master. What do y'all think?

I'm leaning towards slave myself, as the under hood temps don't change all that much with the weather, but under car temps will be much higher when the pavement is 180 degrees.

Those have an hydraulic throw out bearing instead of a slave, not an easy fix.
Was the master out of/low on fluid?

Fluid was very low. I filled it up yesterday and it is still full today.
You're correct about the slave being hydraulic.

Pretty good YouTube Video

Mine was doing that Christine and I went to Weatherford a couple a weeks ago and let the truck sit about 1/2 and hour and no clutch..... Fluid level was normal and no signs of leaks.

Limped it home and I gravity bleed a couple of reservoirs worth of new brake fluid thorough the system and took several long trips. No issues.

My theory is the 18 year old fluid that drained out like black swamp mud was more water and grunge than brake fluid.

Does your F150 have the slave in the bell housing? Who thought that was a good idea??

YMMV

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Originally Posted by POS Racing

Does your F150 have the slave in the bell housing? Who thought that was a good idea??

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It does...very stupid design. Can't even bleed it really without boogering up (and replacing) the line like they showed in the video above.

Is yours inside the tranny? If so, how did you bleed it?

It has a bleed nipple that you can get to on the transmission itself.

http://www.justanswer.com/uploads/BO...eder_screw.JPG

Also best vid I found on Youtube on bleeding the clutch on a ranger should be similar to your F150:

If you do that, use Castrol GT brake fluid.
It is not Glycol based and acts to swell seals a bit, giving longevity.
It may buy you another few years.

Its hard to find these days, but I would go in on a group buy.
http://www.motorcycle-superstore.com...e_Fluid_--.jpg
Its the only fluid to use in British cars.
I found out that the hard way in my MGB, one night on Spring Valley.

I don't think mine has that bleeder but I'll go check. Thanks guys!

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Originally Posted by sammm

I don't think mine has that bleeder but I'll go check. Thanks guys!

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It should have one.

Here is what the google shows should fit your truck.

http://images1.carpartsdiscount.com/...87z7a508ac.jpg

You are correct, I found the bleeder. I ran 2 or 3 reservoirs of fluid thru it to flush it. Haven't had a chance to drive it yet.

Well done, gents. I'm glad this solved itself without any real effort on my part. Looks like Ford wins again!

I too will go in on a group buy for that castrol stuff.
http://www.amazon.com/Castrol-GT-LMA...gt+brake+fluid

http://www.allzim.com/store/cart.php..._detail&p=1268
(Bedford - they have ATE, too)

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Originally Posted by sammm

You are correct, I found the bleeder. I ran 2 or 3 reservoirs of fluid thru it to flush it. Haven't had a chance to drive it yet.

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How nasty was the fluid??

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Originally Posted by POS Racing

How nasty was the fluid??

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Like yours...black swamp juice.

Back from the dead! Sammmm have you had any more problems?

The Ranger decided to disengage the clutch on its own just minutes after picking up my better 1/2 downtown last night. Got it just out of Downtown before it gave up on all forward drive.

Shut it down sat for 20 minutes in the 99 degree warmth and then it went back to what we consider normal and made it home... Fluid looks new still.

Took her to work this morning and it shifted fine...

No more problems after gravity flushing the line and filling the cylinder back up.

Quote:

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Originally Posted by Rogue

http://www.motorcycle-superstore.com...e_Fluid_--.jpg

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So ... this is BETTER than the Valvoline synthetic?

Here we are 2 years later and my truck had the same symptoms today. It did have fluid in the master this time, but clutch would not engage.

Had to get it towed home from Grapevine this evening.

I'm thinking slave cylinder this time...any thoughts?