I have an 84 2.5 5 speed and the clutch is not fully disengaging. In the past year I've installed a new Isuzu trans, Stage II clutch, pressure plate, TO bearing, master/slave cylinders. I drove the car for about 2 months after this rebuild and the clutch recently got worse. I tried bleeding the clutch (according to Archies instructions) and this did not help the slave cylinder travel, which is only 1/2" with the pedal fully depressed. I understand it must travel 1-1/4" to fully disengage and I am pretty stumped on where to go from here.

I've read that the stock pedals can bend. This is my last hope (besides the line, which seems unlikely). My question is how can I tell if the clutch pedal is bent? It appears to be slightly higher than the brake pedal but only so slightly. Can someone measure how for the top of the clutch pedal travels (moves the master cylinder rod) so I can check if this is the problem. Anybody have any other ideas on what could be happening here?

Take a look at this thread

https://www.fiero.nl/forum/A...060206-2-062105.html

and this one

https://www.fiero.nl/forum/A...030819-2-035220.html

Well it if finally Spring and my fiero is still sitting in my garage. I cannot seem to figure out this disengaging problem. Let me retrace my steps...

* Had a shop install a new Isuzu 5 speed trans with stage II clutch, pressure plate, throw out bearing from the fiero store. Also put in a new slave cylinder. Drove the car for 2 months with no problems.

* The car starting having trouble getting into gear one night and the next morning it wouldn't disengage at all.

* Got it home, bled it (gravity and pressure). Only 3/4" of slave travel.

* Replaced the master cylinder, no additional travel.

* Pulled the line out to inspect for leaks and there do not appear to be any. Pulled the master/slave cylinders and pulled the boots to check for leaks, none there either.

* Installed a steel clutch pedal and reinstalled my master/slave & line. Gravity bled it with a one man bleeder (kept master cylinder full and I pushed in the slave rod to rid air). No air bubbles whatsoever, but still 3/4" of travel.

I observed two odd behaviors of the clutch hydraulic system. The master cylinder rod travels 1.55" fully pushed in. The slave cylinder is only moving .7". I understand that there are two different master cylinder designs. Is it possible that I have a mismatch of slave and master cylinders? I.E. the master cylinder bore is smaller than the slave cylinder bore.

The other thing is the bracket holding the slave cylinder flexes ever so slightly with the clutch fully depressed. Not much movement but I wouldn't expect any. Everything is torqued down hard. Does anyone with a working clutch see similiar behavior at the slave bracket?

I am really stumped on this one. I would take it to a local shop but I don't think that they could solve this problem once and for all.

OK, look at your clutch pedal. It should rest slightly higher than the brake pedal. If it does not, you are hitting the floor with it before your master cylinder has gotten a full stroke. If so, take out the master cylinder rod and straighten it a tad, until it pushes the clutch pedal up high enough. All the bleeding in the world won't help if you aren't stroking fully. I've straightened out 3 Fieros this way so far without a hitch. This also assumes that your pedal is not bent. If it's bent, it should be obvious.

I used a washer on the right hand side of the clutch pedal to straighten out the master cylinder rod. I measured the travel of the original master cylinder rod (out of the car now) and it is 1.55". The installed master cylinder has the same travel 1.55", so I do not think that this is the problem. Thanks for the suggestion!

I had the same problem after recently replacing the clutch. I bled and bled and could not get it to disengage. One thing I discovered is that I could get about 1/4-3/8 of an inch extra stoke in the master if I lengthened my banjo. So i fabbed up my own adjustable banjo by cutting it in 2 and threading each piece 5/16 18 NC and adding a similarly threaded coupler between them. This did not entirely solve the problem but did allow me to be able to get it to disengage but only just (my problem is actually related to the clutch I installed). I think next I am going to swap in this http://www.wilwood.com/Prod.../005-CSBMC/index.asp master from Wilwood that has a larger bore than stock. Larger bore means more fluid moved and more travel at the slave.

Dave

[This message has been edited by Dave E Bouy (edited 04-04-2009).]

Good ideas Dave! Does anybody know what the bore sizes on the master/slave cylinders are? Still wondering if I have a mismatch of parts....

Make sure the bracket is installed corectly on the slave cylinder. If it is backwords it will not disengauge fully. I hope this helps.

How much effort does it take to push the clutch arm? Should I be able to do it by hand?

I believe that all master cylinders have the 17.75 mm bore, that translates into .69 or so inches the Wilwood mc comes in three different bore sizes the largest being .750. As far as the slave goes the isuzu and the 4 spd have 13/16 in bore. The getrag slave is a different beast all together.

Thanks for replying again Dave. I was asking about the clutch arm because the clutch slave is flexing at full push. So I was thinking mechanical interference with the clutch arm/fork. Not sure if this is worth exploring though due to the effort involved.

As far as the bore sizes, I did more research last night to determine if I had mismatched parts. Since I am positive I have a Isuzu slave (bleeder screw 120* from the line) there is really no way that I do. To clarify, the slave cylinder bore is the smaller of the two designs and the master cylinder bore is the same in either case, just like you said Dave.

My last two hypothesis were, bellhousing separating from the block when disengaging the clutch (which it wasn't) and problems in the line somewhere like swelling at the braided peices (which do not seem to be swollen). So what else should I check? I've pulled up probably 15 different threads on this same subject (4cyl / 5 spd, not enough slave travel) and few had conclusions or were solved by bleeding / clutch pedal replacement.

I think that I am going to roll it to a shop up the street and pay for a diagnosis because I've wasted a lot of time with no results. Thank you for all of your reponses. I PROMISE that I will post my final fix to this problem to hopefully help others in the future.

Bad slave cyl, or dry master cyl.

Hmm.... Just wondering here... If you replaced an 84 4-speed with an Isuzu, you would have had to get a new clutch slave, because the 84 slave can't be used with the Isuzu. So I'm wondering if you might have got a Getrag slave by mistake. It has a larger piston, and therefore travels less when the clutch pedal is pressed.
An Isuzu slave looks like this:

If you have an Isuzu slave, you can take it apart and put in a Toyota piston to improve it, like this.

[This message has been edited by TopNotch (edited 04-05-2009).]

My slave cylinder looks quite similar to the above picture. What does a getrag slave look like in comparison?

It is shorter and fatter, and does not have the threaded rods pre-installed.

According to Josef644, if I remove the slave from its bracket and let hang I should only be able to push the clutch pedal 1/16" before it gets hard or there is air in the line. Well I can push my pedal 2.5" before it resists. So I guess I am another person who cannot bleed a fiero clutch properly.

I disconnected the slave and let hang. I wedged the slave between the tire and wheel well to make sure that the slave piston was all the way in and couldn't hold any air. Next, I bled well over a pint of fluid without any bubbles at all. I pushed the pedal few times to help move more fluid and a few bubbles appeared at first but went away after another pint. This didn't help the slave travel. I am at .6" (from .75").

Could something in my system be pulling in air? I can bleed brakes on any car without this kind of hassle. I've tried Archie's method, gravity bleeding and this last "creative method"... What am I doing wrong? How can I get all of the air out and get a hard pedal throughout the entire pedal stroke???

Here's something I did to at least ascertain that the clutch would at least disengage mechanically. I took a length of 1/2 in square tubing and a chunk of 3/8 in threaded rod. I threaded a nut onto the rod and inserted the rod into the tube. I the end of the threaded rod into the clutch arm and the end of the tube against the inside of the lower frame rail. I then began to spin the nut so that it backed up against the tube. As I tightened the nut against the tube the rod was forced out against the clutch arm. When I figured that I has moved the clutch arm enough I got in the car, fired it up and it shifted into every gear no problem. This at least helped me determine that the problem was in the hydraulics and not a problem with the clutch itself. Keep pluggin away.

Dave

[This message has been edited by Dave E Bouy (edited 04-07-2009).]

Did I screw up my slave with the last test? In my fiero repair manual it says...

"Prior to any vehicle service that requires removal of the slave cylinder, the master cylinder pushrod must be disconnected from the clutch pedal. If it is not disconnectred, permanent damage to the slave cylinder will occur if the clutch pedal is depressed while the slave cylinder is disconnected."

Does this mean that it will damage the seal on the piston within the slave? I'm thinking of swapping in the MR2 slave piston just to be sure that it seals. It is only $10 at Autozone. Something has to be sucking air into the system. Just not sure how to troubleshoot which peice is causing it.

If you did my test , you did not damage anything. 2 1/2 " of travel is air in the line. Plain and simple. You might damage something by stomping on the peddle with the slave off and hanging down, but not by just pushing in with your finger as I instructed.
Joe Crawford

What I don't understand is if I have 2.5" of air in the line, why am I getting only a few bubbles when I bleed it? How is it getting in there? Which part of the hydraulic clutch system is the problem? I've bled this clutch to no end and still can't rid all of the air in it!!

Yesterday I think that I narrowed my problem down coniserably...

I bled the clutch system with about three master cyliners worth of fluid. NO BUBBLES! I detached the slave from its bracket and depressed the clutch pedal (with my finger), it moved all the way to the floor ON THE FIRST PUSH. On the second (or third or fourth) time I pushed the pedal it traveled only 1/4". This means that the system has a leak in it somewhere because it dispelled the air on the first push.

I double checked for fluid leaks but there do not appear to be any. I am assuming that this is a leak at the slave cylinder bled screw. I don't think it is sealing completely. It has always felt "loose" when I bled the clutch. Has anyone had success with the fiero slave cyilnder? Does anyone know where to get a better quality one such as AC Delco? Part numbers?

Thanks again for all of the help so far!