Why does my clutch pedal stick to the floor?

[prayers1 153]

I already know that I'll need to replace the Brake/Clutch pedal support and will do so with a roller bearing after the car comes back from the bodyshop sometime next year. I have a 4 spd Toploader, all new 11" clutch set up as well as all new Z-Bar linkage.

 

On the 1st run, the only problem with the clutch pedal was that it sprung up too fast (the assist spring caused that).

Yesterday, I took the car out for it's 2nd run and drove for about a 1/2 hour. Everything ran well except the clutch pedal started to stick to the floor. At times I had to put my toe behind it to pull it up.

 

If it matters, the clutch starts to engauge about 3-4" from the floor. Is that OK or should the grab be a little closer to the floor?

 

As I'm getting use to this clutch set up, I find myself putting the pedal down to the floor on each shift. I have learned now to feel when the clutch engauges instead of pushing it all the way to the floor. However, especially coming at a full stop or on a hill I still find that I push it all the way to the floor.

 

What might be causing the pedal to stick?

[BuckeyeDemon 211]

what type of pressure plate? diaphragm or long?

 

the instructions with the Centerforce DF i put in mine stated to remove the assist spring.

[stangs-R-me 121]

Since you have a Diaphram type clutch, I've been told that the assist spring (that you have not yet removed) can cause this.

 

Any possible binding due to "the likely to be worn out" pedal shaft bushings will also add to the force of the assist spring holding it to the floor.

 

Doug

[prayers1 153]

OK. I have no experinece in this situation, but I'll take your word on it. I was puzzled why it didn't happen when I first took the car out. The only other thing I can think of, is that when I just replaced the rear, I took the rear brake line off the proportional valve to blow it out, I took the clutch pedal rod off the Z-bar and the Fork adjuster rod fell off. I had to unscrew the adjustment rod from it's already set position to get it back on the clutch fork and then readjust again. Maybe this time my clutch setting has caused something to allow the clutch pedal to stick.

Just a thought, I really don't know.

I thought that this thread might lead to an easy fix. Thanks to all for your input!

[stangs-R-me 121]

You may want to check the push rod adjustment again. When I put mine back together, I had to adjust the nuts way out (from where the prior 3-finger clutch was) to get it to spec and it just did not seem right. Got in the car and actuated the pedal and there was a "pop" ... went back under car and had to re-adjust back to about where it was originally and it felt normal again.

 

So I'm guessing the TOB was not completely seated on the PP diaphram fingers and that was the "pop".

 

Doug

[prayers1 153]

How much play are you giving on the rod adjuster?

 

I've read somewhere .136? I'd like if someone can say in inches.

 

To get that gap, I believe to manually with your hand push the fork towards the front then see how much gap there is at the rod between the fork end & adj rod. I think I shot for at least 1/4 gap, just enough so that the rod doesn't fall out.

 

What do you think about that. How do you go about freeplay and how much of a gap do you use.

 

This discussion is open to all others as well.

[LoneWolf2U 136]

There should be a spring that holds the lower rod inplace to the clutch fork hole.

The pedal sticking to the floor is an over extension of clutch travel.

On a diaphram type PP, it can push the fingers too far inward and cause this.

 

Engagement of the clutch 3-4 inches off the floor is way too much travel, My guess is that you don't have enough freelay in the clutch linkage.

This comes from not having that lower spring to hold the fork and rod in place, so you are using the freeplay adjustment to compensate to keep the rod in the fork hole.

[1969 Mach1 14]

What type of clutch is this, OEM 3-finger style or diaphram? Do you have all 3 clutch linkage springs in place?

[prayers1 153]

Never thought of over extending the diaphram! That makes very good sense.

You say, engagement 3-4" form the floor is too much, then what do you shot for.

Are you looking for the clutch to grab near the floor or near the top.

 

My understanding and correct me if I'm wrong, is that the engagement closer to the top means a clutch needs to be replaced.

 

I like to feel the engagement closer to the floor. In fact I would like it to grab at least 2" from the floor.

[1969 Mach1 14]

prayers1,

 

Please post if you get your diaphram clutch working correctly. I wanted to go that route but was warned not to when using the stock linkage. Stock linkage geometry does not work as well with diaphram clutches. I was told the pedal travel from full clutch dissengagement to full clutch engagement would be very short, have to be close to the floor, never feel correct, and the car would be harder to drive. Some of the same issues you are experiencing at this time.

Edited December 20, 2011 by 1969 Mach1

[LoneWolf2U 136]

I had a diaphram pp in before I went to a racing clutch set up.

Using the stock linkage and it worked fine.

The linkage adjustment is key to make any clutch work properly.

In order for the adjustments to work, the parts need to be in good shape and there.

 

Prayers1, You will have to repair your upper bushings first or you will be chasing your tail trying to make it all work.

 

You need to have the small spring that goes from the fork to the lower end of the Equalizer bar where the adjustment rod hooks into.

This springs only job is to keep the fork and adjusting rod in place, it does nothing for returning the pedal.

The upper spring above the pedal has the job of returning the pedal to resting spot.(fully up)

 

Adjustments start with free pedal travel, This is the amount of travel the pedal goes down before the throwout bearing contacts the pp fingers.

1-2 inches of travel is a good starting point.

Once you have that, Now your after at what point the clutch starts to engage when you lift your foot.

Best point is 2 inches off the floor (my opinion) To get this adjust correct is when you go to the adjusting rod.

If you shorten the rod the clutch will engage sooner or closer to the floor.

If you lenghten the rod the clutch will engage with the pedal farther from the floor.

[02Lightning 10]

I had the same problem with my centerforce clutch with the pedal sticking to the floor. I removed the compression spring under the dash and all is good now.

[prayers1 153]

I put the Mustang on the trailer and towed it to the Bodyshop yesterday. After unloading it, I was getting some questions under the hood and found the spring attached to the fire wall and top Z-Bar remained unhooked after I took it off to bleed the rear brake line. I really haven't confirmed it, but this maybe one of the problems with the clutch pedal sticking to the floor. To answer one of your questions, I did replace all bushings in the Z-Bar.

I just ordered a ton of stuff from CJ and won't be able to drive the car until early spring.

 

Thanks to all who showed a concern answering my questions.

 

Have a Merry Christmas and a Happy New Year!!!!!!!!!!!!!!!!!!!!!!!!!!!

[Patriotgamez 14]

I had the same problem with my centerforce clutch with the pedal sticking to the floor. I removed the compression spring under the dash and all is good now.

 

I know this is an old thread, but I am about to install the Centerforce diaphragm dual friction clutch and came across the literature recommending removal of the assist spring

[Steve69 0]

Mine did the same thing. It was my clutch linkage binding. I installed Heim joints and rod on both ends of the Zbar. It works really well now.

 

Heres a pic

 

[GT350 16]

I know this is an old thread, but I am about to install the Centerforce diaphragm dual friction clutch and came across the literature recommending removal of the assist spring

 

you will need to remove the pedal assist spring

[prayers1 153]

Check out my recent thread How do you take the interior clutch spring off .

 

About a month ago, I just got the car back form the body shop, so I was reliving the same problem. The main reason the pedal was sticking to the floor was because the upper Z-Bar spring was off. However, I still had the same problem with the clutch lifting fast on its own and I couldn't get a good feel with my foot for the clutch adjustment. Whats happening is that the diaphram PP is easy to push in vs. the 3 tab PP, so the Clutch Assit Spring isn't needed unless your using the 3 tab type. As you will find out, I did remove mine and it makes a world of difference, I can feel when the clutch is starting to grab where as the other way the clutch pedal flew up by passing that sensation.

 

As for the Clutch linkage, all of mine is new and I also thought to replace the same with Heim Joints, but now that I removed the Assit Spring I now have a better feel for the clutch and will keep the original equipment, it seems to work fine for now.

 

I still think the Heim Joints are better, but time will tell.