Hello everybody.

Been struggling with this ever since putting it all back together after a tranny rebuild.

I have an 84 se with a 5-speed tranny out of an 86. Thought it was the tranny at first, but clutch will disengage fully if I pre-load it a bit.

I have an inch of travel, all new components, steel pedal, very little top-play, no leaks or sagging. I bled it 3 separate times using the front end lifted with the slave compressed and bleed valve at the top.

My next idea is to get an adjustable master rod and pull the clutch pedal towards me somehow. all I need is about another 1/4 inch.

What am I missing? I have studied this site and everyone says the steel pedal fixes 95% of the problems. Am I the 5%?

Thanks

Ty

Ty,

Is the clutch pedal about 1" higher than the brake pedal? You NEED that for full throw.

Can you get release if you 'pump' the clutch? If so you STILL have air in the lines.

Larry

Is your banjo sitting the right way? The loop in the arm should be facing up. I've heard even that small thing can be the difference between it disengaging and not.

Clutch bleeding prodeedure
You can do it your way, But this method always works for me.
After checking to be sure there are no leaks in the Clutch Hydraulic system.
Complete ALL of the following steps before test driving the car:
1) Install a helper in the drivers seat to push in and let out the clutch pedal on command.
2) Remove the cover from the Master Cylinder reservoir.
3) Top off fluid in the reservoir.
4) During the course of this procedure DO NOT allow the "helper" to "pump" the pedal. The "helper" is to depress and release the pedal on command only, DO NOT PUMP THE PEDAL. (See theory below)
5) You will be opening and closing the bleed screw on the slave cylinder as instructed below. CAUTION: During this procedure protect your eyes from squirting brake fluid.
6) (Helper) Press clutch pedal in fully and hold.
7) (You) Open the bleed screw to allow fluid to escape.
8) (You) Close bleed screw.
9) (Helper) Release pedal completely
10) (You) Top off fluid in reservoir.
11) Repeat steps #6 thru #10 no less than 5 times before going to #12 below. NO PUMPING!
12) You have now bled the Master Cylinder and the hydraulic line. YOU ARE NOT DONE YET!!!!! We must now bleed the Slave cylinder. (This is what the manual doesn’t tell you)
13) With no further action to be done with the clutch pedal, you can no remove the "helper" from the drivers seat and have him (her/it) help you do the following.
14) After topping off the Master Cylinder, completely remove the bleed screw from the slave cylinder.
15) Have the "helper" stand at the ready with the bleed screw and the appropriate wrench for installing the bleed screw.
16) PROTECT YOUR EYES!
17) With the bleed screw removed. With both hands grab the push rod coming out of the slave cylinder and push it into the slave cylinder as far as it will go AND HOLD it in.
18) Your "helper" will now install and tighten the bleed screw while you hold the plunger in.
19) When bleed screw is tight release the rod and as it comes out guide it into the proper position on the clutch arm.
20) Top off the Reservoir and the job is complete.

Theory:
Why do I insist that you REMOVE the bleed screw when pushing the plunger in on the slave cylinder? This is simple hydraulics. Fluid or air will always go the direction of least resistance. When you are pushing the rod into the slave cylinder you will find that it is impossible to push it in at a slowly and steadily pace. If you push it in too fast with the bleed screw still in and just unscrewed a few turns some of the brake fluid and/or air in the slave cylinder will go back up the hydraulic line that you just bled, thus necessating your starting over.
When bleeding your clutch....The biggest mistake or miss-conception a person can make is to pump the pedal.
The clutch Hyd. system, unlike the brake Hyd. system SHOULD NOT BE PUMPED. The only thing that happens when you "pump" the clutch is that you make any large air bubbles in the hydraulic system into a bunch of small air bubbles. BTW these small air bubbles are harder to bleed out than larger bubbles.
You cannot "pump up" a clutch. If you have to "pump up" the clutch to make a shift then you have a leak and you can bleed the system a dozen times to no avail.
On the clutch, think about it now, if you could "pump-up" the clutch wouldn't the T.O. Bearing tend to invert the clutch diaphragm and travel toward the engine until it met up with something solid like the flywheel. On a braking system, when you "pump-up" the brakes you force the brake pads into the rotor until the line pressure builds up enough that the resistance you feel when pumping the pedal increases. Further, as you press harder and harder on the brake pedal the pads just increase their pressure on the rotors.
GM Thought this through when they designed the system. To avoid "pumping up" the clutch hyd. system, GM put in a small bleed back hole in the master cylinder. (BTW not an original idea, all Hyd. clutches have it) This bleed back hole relieves line pressure every time the pedal is at the top of the stroke. Didn't you notice when you "pumped up" the clutch pedal that it doesn’t firm-up like the brake pedal does?
The only thing you accomplish when "pumping up" the clutch pedal is to take any air bubbles that are in the system and atomize them into smaller air bubbles, thus making the problem worse. Remember when you were at the soda shop, as a kid, and your parents kept giving you hell about playing with you soda and straw? Same theory here! The more you move that soda through the straw the smaller the air bubbles become.
BTW the "hand pumps" work ok but I’ve never needed to buy one yet. With the hand pumps you still need to ensure that the slave cylinder gets completely bled.

Archie

[This message has been edited by Archie (edited 12-11-2013).]

Wrong TO?

Archie, you’re dead on with bleeding the slave out. I tried to bleed the slave by pulling it in and only slightly opening up the value. After 2 pulls the slave had no fluid left and I couldn't get anything to flow by pressing the master. I lost all compression on the system. I had a heck of a time trying to bleed out my system. I probable could have got it to work if I had done your steps 6-10 enough times. Finally I got a pump and when I first started to pull though the system I got a ton of air from the line next to the slave. The only way it could have gotten in would have been how you described.

Thanks everybody.

I ordered an adjustable banjo from Rodney. Actually talked to him - great guy.

I am gonna bleed it again this weekend with Archie's advice once I get my helper over.

How can a bad throw out bearing be the cause? I have been thinking about everything that could be wrong inside the bell housing once it was all together, and can only come up with broken forks on the TO bearing. Rodney said a loose pressure plate could be the cause - so I may open the bottom plate and check, but am really sure they are tight (unless I am a victim of sabotage).

Hold on.

Ty

quote Originally posted by tywhitaker: I have an 84 se with a 5-speed tranny out of an 86.

quote Originally posted by tywhitaker: How can a bad throw out bearing be the cause?

Each tranny has it's own particular throw out bearing.

You can't use a throw out bearing from a 4-spd Muncie with a 5-spd Isuzu... if that's what you've done.

Awww, yes. Patrick

I do have a TO bearing for the 86 Isuzu. Thanks.

Ty

Since the 84 used a different slave than the Isuzu, I'm wondering if the bore of the 84 master and slave are different from the 85 and later Isuzu equipped cars. Could it be that with the Isuzu slave Ty has to use, it's that the master can't push enough fluid to make the slave travel the required distance? I know that the rebuild kits from auto parts stores are specific to the 84 slave.

quote Originally posted by fierofool: Since the 84 used a different slave than the Isuzu, I'm wondering if the bore of the 84 master and slave are different from the 85 and later Isuzu equipped cars. Could it be that with the Isuzu slave Ty has to use, it's that the master can't push enough fluid to make the slave travel the required distance?

You bring up a good point, but as far as I know, all Fiero clutch masters move the same volume of fluid.

I did the same swap as the OP has done. I put a 5-spd Isuzu in my '84. Works fine, but I did eventually make my own adjustable clutch banjo to increase the throw a bit (because the original banjo was shorter than others I have seen).

2nd that... the bores are the same, but the banjos are different. i couldn't get mine to release because the banjo was installed upside down. A mm here and a mm there can make ALL the difference in the world!

It just hit me last night (this morning) thinking about the TO bearing. What if one of those retaining clips popped off and if now in front of the fork?

My thinking is that it would push back against the arm and push the rod a bit into the slave cylinder. If this is the case, I should be able to push the arm a bit towards clutch disengagement, right?

I does move, about 1/8 inch and spring back when released. **** !

Ok. My thoughts are now on how to keep the TOB engaged to the pressure plate without splitting the tranny. Any idea if I can get to the TOB through the inspection plate?

Thanks

If the 84 banjo is shorter, then wouldn't that take away from the "1 inch above the brake pedal" standard? It would be allowing the MC internals to bottom out at the back end of the bore?

I'll try to find one of my banjo rods so Ty can begin with a known length with his adjustable rod.

You can't get to the TOB without removing the trans. That is, unless you cut a hole in the bell housing. The hydraulic system is self-neutralizing. The small spring in the slave keeps a very slight amount of pressure on the pushrod and release fork for the purpose of keeping the pushrod captured.

[This message has been edited by fierofool (edited 12-12-2013).]

I have an adjustable banjo ordered from Rodney. Should be here next week.

Ty

I couldn't get the banjo out of the MC, but as best as I can measure, the length from where the shaft meets the mushroom end to the center of the banjo eye is 5 7/8 inches. This is measured on an 87 MC. This picture is from my files.

[This message has been edited by fierofool (edited 12-12-2013).]

FYI:

Progress.

My suspicion about the springy thingy on the TO bearing is plausible. I simply put a spring over the slave linkage to load the shift fork back onto the back face of the TO bearing and the to bearing against the PP. Not a big spring, i could compress it with the fingers of my right hand.

Finally....disengagement! I could drive this thing now. It still makes a slight growl going into reverse, so I am gonna wait for the adjustable banjo and hope it gives me just a bit more. This will probably require a bleed, so I can follow Archie's procedure above.

OK, like all good theories require before acceptance, can anyone poke any holes in this?

Thanks,

Ty

For bleeding the clutch I replaced the stock bleed nipple with a one man one and adapter, part number SB-BMW-S which I got from http://www.racerpartswholesale.com
Adapter goes into the slave, nipple goes into the adapter. Dead easy.

------------------
Anything I might say is probably worth what you paid for it, so treat it accordingly!

Dave

www.ltlfrari.com

When I had mine way back when, I could never get the thing to work right until I installed a Wilwood 2lb Residual Pressure Valve. For normal driving, it was fine. If I did light-to-light runs 1-2 would be fine 2-3 might sometimes slip a bit.

Archie is dead on with the bleeding of the slave cylinder. I had to make about 3 attempts at it and I finally got all the air out. I would jack the rear up and you could see small bubbles come out. I actually bled it myself with the car window down and a long stick.
Sometimes the bleeding is frustrating but remember never let the master cylinder get low on fluid when bleeding or it's back to square one....experience.
Also I have 1" travel on my slave cylinder and it goes in and out of gear.

Good luck and I hope that is all your troubles is air!!!