Clutch pedal "sweet spot" keeps moving!!!

[Tunerbuilder]

So i've been driving my newly aquired 2G for about two weeks now, trying to fix any issues that arise since is has been horribly molested by a previous owner (poorly installed mods, removal of things when they break and NOT replacing them, welding the wastegate shut on the Frankenstein'd 16G turbo, and a generally half a**'d job of taking care of this poor 2G.). One of the issues i've been unable to find a fix for is inconsistency in the position of the clutch pedal sweet spot (release and engage point) in the pedal stroke. I'm not too familiar with DSM's in general; but to my knowledge the sweet spot in a hydralic clutch set-up should not move up or down in the pedal stroke. Every time I fire the car up and press the clutch pedal to shift I find the sweet spot is at either the very top or the very bottom of the clutch pedal stroke. And at times while driving it moves so far to the beginning of the stroke, the clutch barely engages when the pedal is completely released. The clutch pedal makes a full stroke every time I press/release it, but the sweet spot is different about every four times I press it while driving.

The reservoir is full and the clutch pedal is firmly bolted to the fire wall. I'm thinking bleed the system, but the clutch will disengage and engage fine most of the time. It's just the sweet spot that keeps moving. Any help is greatly appreciated.

 

[98talonblack]

My bet is a tiny hole somewhere in the hydraulic system i had a fiero that did the same thing turned out to be a pin hole in the brake master cylinder rubber gromet.

 

[SleepingTSI]

Have you bled the clutch?? I've had the same weirdness from needing to bleed the system. Might also want to make sure the clutch adjustment rod locking nut is tight...

 

[Tunerbuilder]

I have not yet bled the clutch, but I will bleed the system as well as check for leaks on monday.

 

[Fullthrottle7]

Sounds like the 2g "pump up" issue to me. As the clutch rod is adjusted farther and farther out, it eventually reaches a point where the bleed hole doesnt get included in the piston stroke anymore so as you press in the pedal more and more times it keeps building more and more pressure without actually moving like its supposed to. Does it feel rock hard after a few times of engaging/disengaging, or does the effort it takes to push it to the floor stay consistent and also linear? Also, when you say "beginning of stroke" are you referring to when you first start pressing it toward the floor or as it first begins to come back up?

 

[1G Eclipse94928]

I have not yet bled the clutch, but I will bleed the system as well as check for leaks on monday.

Clutch Drag Kills Synchros! – Jacks Transmissions LLC

Check for all of this as well if you think he installed the clutch.

Actually its probably a good idea to test just from the condition of the rest of the car.

 

[Tunerbuilder]

Sounds like the 2g "pump up" issue to me. As the clutch rod is adjusted farther and farther out, it eventually reaches a point where the bleed hole doesnt get included in the piston stroke anymore so as you press in the pedal more and more times it keeps building more and more pressure without actually moving like its supposed to. Does it feel rock hard after a few times of engaging/disengaging, or does the effort it takes to push it to the floor stay consistent and also linear? Also, when you say "beginning of stroke" are you referring to when you first start pressing it toward the floor or as it first begins to come back up?

It's pretty consistent pressure, never gets rock hard or really soft. By beginning of stroke I mean when I start to push the pedal down.

Clutch Drag Kills Synchros! – Jacks Transmissions LLC

Check for all of this as well if you think he installed the clutch.

Actually its probably a good idea to test just from the condition of the rest of the car.

Good read! I will definitely try the drag test today.

 

[Lou98GSX]

make sure your crank thrust bearings aren't worn . you need 2 people to check one pressing against the crank pulley and the other inside and ready to press on the clutch pedal . if the pulley moves out a lot then that will change your clutch pedal position .

 

[Tunerbuilder]

make sure your crank thrust bearings aren't worn . you need 2 people to check one pressing against the crank pulley and the other inside and ready to press on the clutch pedal . if the pulley moves out a lot then that will change your clutch pedal position .

I'll try that right now. So I just tried that, and there is no visible movement of the crank pulley inward or out ward when the clutch pedal is pressed and released multiple times. Thank god for that.

I also tried the drag test from the link on 1G's post. And my car stayed perfectly still all the way up to 6500 rpm's. So the drag is non existent. I also inspected the clutch fluid lines from master cylinder to slave and they are all dry. I went for a quick spin to see if the clutch was still acting up; and the sweet spot was 1/3rd of the way down the pedal stroke for about 7 shifts. Then the sweet spot slowly started to move to the top of the pedal stroke when fully released. My tools are all locked up at work for the weekend, but on monday I will bleed the slave and master cylinder. Hopefully a good bleed will fix this issue.

 

[Tunerbuilder]

I bled the master and slave cylinders, and it still moves but not as much. The sweet spot goes from 2/3rds of the way down the stroke from the top, to almost right at the top the stroke. I did notice there is a small metal cylinder shaped object about 2 feet away from the slave cylinder. The clutch line goes into one end from the slave and out the other end to the master cylinder. Could that metal cylinder shaped thing be an issue as well? I'll try to get a pic of it tomorrow.

 

[nelliott500]

In regards to the cylinder near the clutch slave:

Clutch Restrictor Removal FAQ

 

[Tunerbuilder]

Well, I will be removing this "Clutch restrictor" as soon as my SS clutch line gets here. Thanks for the link, hopefully that fixes the issue.

 

[GofaST4life]

A few things, as I have had my fair share of Clutch issues.

Where does your clutch fork end sit in the tranny window? Take a picture and post it up.
Have you adjusted the Master Cylinder per Jacks Trans instructions?
How did the drag test work out?

The SS line is an awesome upgrade. Once you get that installed, bleed, bleed, bleed, then bleed again.
If your still having problems, AND you've check your clutch fork. I would recommend a new Master and a new slave. They are not expensive and easy to replace.

Report back when you can.

 

[Tunerbuilder]

Alright, so I've installed the ss clutch line and bled just over 4 liters of fluid through the system. I also adjusted the master as per jacks awesome vid. But, I found the master cylinder is leaking ever so slightly inside the driver side footwell. I think that could be the cause of my problem, but the grab/release point did get a bit better after adjusting the master via jacks vid. hopefully a new master cylinder will fix this issue. Ill post a pic of the fork position in a few minutes.

 

[nelliott500]

That would definitely be your issue. That leak is allowing air past which is limiting the amount of pressure the hydraulic system can put on the clutch fork.

 

[Tunerbuilder]

This is the clutch fork before I installed the ss line.

 

[jettster91]

I had a simpler problem once on my 2g, I ended up having to Bleed the whole system change out the fluid, and bleed again Finally was normal, A bubble musta been stuck in the right place,

 

[d1978]

I would also inspect the clutch pedal bushing for wear,... its just preventive maintenance.

 

[Lou98GSX]

i think 70% of our problems with clutch issues is that we are not getting all the air out . we had in the shop a mini cooper that we had to change the transmission and after that we couldn't get the clutch to release because air got into the system . after looking online and finding a procedure to get the air out we finally were able to get it to work right . this procedure might even work for are cars . what happens is some of the air gets trapped at the slave cylinder . what the mini cooper techs do is they have a tool that keeps the slave cylinder rod all the way in so its bottomed out then they bleed the system . if we had a way to hold the slave cylinder rod in it might also work for us.

 

[Tunerbuilder]

what happens is some of the air gets trapped at the slave cylinder . what the mini cooper techs do is they have a tool that keeps the slave cylinder rod all the way in so its bottomed out then they bleed the system . if we had a way to hold the slave cylinder rod in it might also work for us.

That's a good point, if I still have issues after changing the master cylinder ill try that.

 

[curt-s]

i think 70% of our problems with clutch issues is that we are not getting all the air out . we had in the shop a mini cooper that we had to change the transmission and after that we couldn't get the clutch to release because air got into the system . after looking online and finding a procedure to get the air out we finally were able to get it to work right . this procedure might even work for are cars . what happens is some of the air gets trapped at the slave cylinder . what the mini cooper techs do is they have a tool that keeps the slave cylinder rod all the way in so its bottomed out then they bleed the system . if we had a way to hold the slave cylinder rod in it might also work for us.

You mean like a zip tie over the rod end and around the slave so that it will keep the cylinder compressed?