Clutch Problems

[Budgetman72]

Hey folks,
I’ve replaced the clutch pedal, master cylinder “banjo string loop up”, slave cylinder which was leaking and bled the lines several times and it still wont release the clutch fully on my 85 GT!  The slave cylinder seems to be traveling full extension which i believe should be 1.2 inches but haven’t been able to measure due to heat shield blocking. All replacement parts are from Fiero Store. What am i missing?


Thx

[f85gtron]

Make sure banjo hole is “down”. Same thing happened to me.
Also, bleeding is tricky. Use every trick you read online.

[Budgetman72]

That may be my problem then i thought banjo string loop was supposed to be up! I’ll flip it over and hope that will fix it.

Thx

[TopNotch]

Try 2-person bleeding.
1. Open bleed valve.
2. Press clutch pedal.
3. Close bleed valve.
4. Release clutch pedal.
Repeat until no bubbles come out.

[Fierofool]

That may be my problem then i thought banjo string loop was supposed to be up! I’ll flip it over and hope that will fix it.

Thx

The banjo rod should be positioned in this manner:

[Budgetman72]

Thanks for the photo, thats the position I have the banjo in and i’ve done the vacuum bleed, then the 2 person bleed, then the slave cylinder bleed to a point the fluid coming out is as clean as going in. What’s next?

[Fierofool]

I have had the most luck with bleeding a good system by using the gravity bleed method.  Pumping the pedal can break up air bubbles in the system, only to have them coagulate again.  This is a one-man operation and can be a blessing if you have trouble when on the road.  Learn how to do it. 

Jack up the left front wheel just enough to get it off the ground.

Fill the clutch reservoir to the top.  Leave the reservoir cap off and the can of fluid open and nearby.  DOT 3 fluid only.  DOT 4 in an emergency.  Never DOT 5, or transmission fluid.

Using a heavy metal tool, whack the side of the slave several times.  This should dislodge air stuck at the pushrod end and allow them to flow up to the bleeder valve.  This is the purpose of raising the front wheel off the ground as it also tilts the slave cylinder upward. 

Open the slave bleeder valve and notice if there are any air bubbles that come out. 

Allow the fluid to flow, keeping watch on the fluid level in the slave.  On occasion, whack on the side of the slave again.  As it nears the bottom, refill it.  At the 2nd refill, allow the fluid to drop to the FULL level, then close the bleeder valve. 

If the system is good, you should have a good clutch pedal. 

Because the slave fluid line passes close to the coolant hose and exhaust, I insulate it with a length of split plastic wire loom, extending from the flexible portion all the way down to where the line is mounted to the frame.  The ribbed plastic acts as a heatsink to keep the fluid from boiling. 

[Raydar]

Did you install Rodney Dickman's master cylinder?
If so, you will probably need to extend the pushrod (it's adjustable) in order to get full extension.
I know of at least two installations (one of which was my own) that required this.

Edit - Ooops... I overlooked the Fiero Store comment.

[Fierofool]

Even with a TFS slave, Rodney's dual seal kit will fit, or pick up one for an 85 or 86 MR2 at your local Toyota dealer. 

[Budgetman72]

I believe I’ve done it all now! The pedal feels a lot better now, however still no release. I noticed while pressing the clutch with engine running slowly trying to put in first the car starts rolling no grinding the gear like it does in reverse, is this still clutch hydraulic issue or something else? Will the Rodney Dickman slave cylinder really make the difference or is there something going on machanicaly?

Thanks for all the feedback!

[Fierofool]

If you can put it in gear, start it and while holding the clutch in, it gradually starts to move, then you have a hydraulic seep.  It's probably in the master cylinder.  Run your finger way up (Edit)along the banjo rod to see if you might have fluid leaking from the back of the MC.  It can run down the firewall and be near impossible to see. (End edit) You can get master cylinders at some of the auto parts stores, but it may be worth the cost of a Dickman unit.  The double seal piston on the slave is mostly to reduce the possibility of air being pulled back into the slave.  Since you have a new slave with a good bore, you could replace the piston yourself.  I think I paid under $10 at O'Rielly.  You'll have to use the spring that's in the slave.  The Toyota spring is too short. 

Reverse isn't synchronized and it's not unusual for it to grind on the 4-speed. 

Something just occurred to me.  I had a release problem and it turned out to be a cracked slave bracket on my first 85GT.  On the second 85GT, when I had the problem, it was the big horizontal bolt that bolts it to the engine.  It had worked it's way loose.  Observe the slave bracket for movement while someone operates the clutch.  If it turns out you need a replacement, I have a couple. 

Does the pedal sit about an inch above the brake pedal?   

[Budgetman72]

Well here’s the update, I've replaced the new master cylinder with Rodney Dickman MC and Still haven same problem! I jacked up the rear end and crawled under to get a better look at the slave cylinder action and noticed what looked like some play in the Clutch Arm where it mounts to the Clutch Fork, i tightened the bolt but  looks like there is still movement before the Clutch Fork rod begins to turn. So with that looks like i need to change the arm or the fork or both.

[Fierofool]

The release shaft is splined and has a place where the pinch bolt passes through the side of the shaft.  When tightened, there should be no play.  It might be that the bolt has been loose for a while and has allowed the splines to wear a little.  Some of the release arms were a problem and were later replaced with cast metal arms.  I don't remember what years or transmissions, though.  I had 2 85's, but don't remember what style arms they had on the 4-speeds before I changed to an Isuzu transmission in them.   

MikeMac has an Isuzu trans that he has removed from his car.  The release arm on it is good.  He may be willing to sell it to you.  I can't help you with the car before the meeting, but if you're available in the morning of Tuesday, the 14th, I am available. 

[TopNotch]

I have a good Isuzu transmission clutch arm in my garage. It doesn't have the pinch bolt, though, because that was missing on the "new" transmission I got from ThaDriver.

[Budgetman72]

Final update! Found the culprit the factory clutch arm was cracked in several places so we replaced it with cast iron from The Fiero Store. See photo