Clutch advise/help

Brett

Brett

True Classic
I've read all the threads, but still want to pick brains... :)
My son's ('87 X) clutch failed while driving, he quit being able to select gears while the engine is running. You can easily select any gear with the engine off. If you put the car in gear, engage clutch and try to start the car, it will roll in the direction of the gear (forward for first, backwards if starting in reverse). If you go ahead and start the car and then lightly hit the brakes the roll will stop and you can rev the engine without the car moving, but you can't change to any other gear. Clearly not getting enough clutch activation. But since you can rev engine without car moving, the clutch can't be completely stuck either (right?). Measured travel of clutch pivot arm is about 3/4", which is much less than other posts suggest I should have (1" to 1.25"). But not too far off from the X I'm driving ('86 X) which has also less than 1" travel. There was some wetness at the master cylinder so we replaced that (new, from Midwest Bayless) than I reverse bled the system. Didn't seem to have any effect, so we replaced the slave as well (also new, also from Midwest Bayless) and I again reverse bled (only one small air bubble observed at reservoir, which doesn't seem right but it meant using a syringe to empty the reservoir multiple times and I pushed about 10 oz of fluid through the system, this being the slave only, I didn't track how much I'd already done when replacing the master) . Still no change in travel and lack of full clutch engagement. I tried normal bleeding (clutch down, release bleed screw, tighten bleed screw, clutch up) and observed a couple more small bubbles, but still no change in travel nor clutch operation.
So, do I have insufficient bleeding? How much do you really have to push through to bleed the clutch? A problem inside the bell housing? Something else I haven't considered?

(BTW, I site source for parts not because I suspect an issue, but just for completeness in diagnosis).

Also, all bleeding was done with the car level. I was thinking since I was pressurizing the system with the oil can trick for reverse bleed that was sufficient, but maybe I am wrong there??

Thanks for any/all help and suggestions! :)
 
Update - out of desperation I tried one thing I hadn't. I pulled the clutch stop off the floor. I now get full clutch operation now (about 1" of travel in pivot arm). I can start the car in gear without it moving and can select all gears with the engine running.
I think this effectively rules out anything internal to the bell housing (yes?)
So, it is really an insufficient bleed?
The pedal feels firm for entire travel after a small amount of free play at the top. FWIW, if I adjust the top stop it changes where the pedal is in relation to the brake pedal (i.e. higher or lower) but doesn't seem to affect where the pedal is when it actually starts moving the clutch pivot arm (about 6.5" from the firewall/floor). In other words, adjusting the top stop just gives more free play, not more effective travel. More effective travel was enabled by removing the floor stop, but that seems a method for troubleshooting, not something I should leave off.
 
I would pull back the boot on the slave, and make sure the additional push provided by the extra throw is not bringing the seal out of the seat area. This would be indicated by a small amount of seepage around the seal, and possibly into the slave boot. If this is the case, it would be the same circumstance I encountered, which was caused by a sheared clutch fork retaining bolt.
 
Hmm with you have two X's can you compare the two to see if the travel is the same.

We have nothing going on this weekend. We could bring our two X's over to compare the 4.

From my trany mechanic day's I am leaning toward a clutch problem. But you getting it to work with the travel limit removed makes Me also think there could be a problem with the clutch arm.
 
I'd be suspecting either:
1) Something went wrong in the linkage between clutch pedal and master cylinder, so the geometry is no longer right. You can remove the pedal box and investigate without opening up the brake and clutch hydraulic systems - and good thing too, because you do not want to redo the bleeding you've done.
2) The master cylinder piston is sticking in its bore on the return stroke.
 
Jeff VanDyke had an issue with the placement of the throw out bearing in the past (it was upside down) but I can imagine one coming unclipped on one end.

Could it possibly have gotten unclipped and now won't travel the full amount?

Any new noises from that zone with the clutch engaged or disengaged?
 
I have the exact same issue currently. Car was parked for winter and I have not investigated other than watched the throw at the slave and did a little bleeding. I suspect hydraulic failure in the master or slave, both of which are new, well 7 years but 50,000 miles. I'll pull my pedal stop and see if it helps although I don't even know if I'm running one at the moment.
The upside down T/O bearing was a fluke perpetuated by inattentive mechanics. That was a PITA and all sorts of hijinks were performed to compensate for it until I figured out what was wrong.
 
THANK YOU ALL for the suggestions - I love this community :)
I'll check on the pedal assembly, but it "feels" normal - normal travel feel, normal pressure/firmness, etc.
And I'll check the seals on the slave during operation per Hussein's suggestion.
And no noises from the clutch area, which I would think there would be with bent pressure plate fingers, or a loose T/O bearing.
Hoping to figure this out before pulling the trans just to check. At this point where we've already replaced the master and slave I want to eliminate everything else before the work of pulling the trans. For one thing the alignment on this car seems to be perfect and I fear messing it up with the coilovers being pulled to allow trans to come out. Ah well, what must be done must be done and of course I will if I have to... :p
 
I would also go back and bleed the clutch system a few more times. It is not at all unusual to have air in the system.

Despite following all the best directions and intentions
 
I wonder if it could be internal seals on master/slave, initial push is good but then fades a bit as pressure leaks past the seals. My slave showed a tiny bit of moisture under the boot.
 
Not good news but it's not unlikely that the throwout brng is toast.
On the later model cars it is always in contact with the pressure plate.
Always spinning.
Not sure why anyone would design this into the system, but Fiat did.
When you replace it, and most likely the pplate and disk, use a spring to pull the throwout brng away from the pplate like the earlier cars did.
 
A LOT of the new car's do this as well.

They also have moved the slave cyclender inside the bell housing (so you have to remove the trans to work on the cyclender).
 
MikeHynes said:
Not good news but it's not unlikely that the throwout brng is toast.
On the later model cars it is always in contact with the pressure plate.
Always spinning.
Not sure why anyone would design this into the system, but Fiat did.
When you replace it, and most likely the pplate and disk, use a spring to pull the throwout brng away from the pplate like the earlier cars did.
Click to expand...

Actually, I think the clutch manufacturers designed it this way & sold it to all applicable vehicle manufacturers - Volvo also went to constant-contact T/O setup in late 70's :)
 
Rod Midkiff said:
A LOT of the new car's do this as well.

They also have moved the slave cyclender inside the bell housing (so you have to remove the trans to work on the cyclender).
Click to expand...

The advantage is simplified design & less moving parts - Volvo went to this design in 1998 - removes the need for throwout fork, pivot arm, and bushings - all parts that wear & introduce play into the clutch. Typically the combined slave T/O's last well over 100K miles, especially if the fluid is serviced. Most cars also went to Dual Mass flywheels around the same time - that I can do without. Makes using a clutch virtually idiot proof though ...
 
Well that might be the excuse they used (less parts) but from my tranny shop day's We saw a LOT of fail's that went from a minor change the slave to a major do a clutch since your their anyway.

Oh and don't get the started on that DUMB dual mass flywheel. %100 Percent that we saw needed a NEW flywheel with every clutch, and a lot of them where the clutch was still service able if the flywheel had not came apart. We pushed to back date the clutch to do away with the dual flywheel thing.
 
kmead said:
I would also go back and bleed the clutch system a few more times. It is not at all unusual to have air in the system.
Click to expand...
Yep, I totally agree with Karl's suggestion. I recently went thru the same agonising procedure (fit new clutch and brake master cyls + clutch slave cyl) that you have experienced, on my '78 1300 X1/9. After bleeding the clutch system (to what I though seemed to feel OK at the pedal) I then tried to shift into gear with the car on the ground - NO LUCK! I then jacked the car back up, high at the rear, and then AGAIN reverse bled the clutch system, using the oil-can trick pumping fluid from the slave cyl thru to the master cyl. I pumped fluid thru until there was absolutely NO sign of bubbles in the reservoir! Lowered the car to the ground, started the engine, depressed the clutch pedal and tried putting into 1st gear. Halleluyah - easy to get into all gears!! It seems that the clutch hydraulics need EVERY mm of pedal action to fully free up the clutch! Best of luck!! :D

cheers, Ian - NZ
 
ianlawson said:
... I then jacked the car back up, high at the rear, and then AGAIN reverse bled the clutch system, using the oil-can trick pumping fluid from the slave cyl thru to the master cyl.
Click to expand...
I thought you tried to push the air bubbles up, the direction they should try to travel anyway, so if reverse bleeding, shouldn't the FRONT be high, rather than the rear, to push air towards the reservoir?
Finally back home, so hoping to do this tonight and really really hoping for positive results :)
 
Last edited:
Brett said:
I thought you tried to push the air bubbles up, the direction they should try to travel anyway, so if reverse bleeding, shouldn't the FRONT be high, rather than the rear, to push air towards the reservoir?
Click to expand...
I had already tried the traditional method of bleeding the clutch with the front of the car jacked up (prior to trying the oil can "trick") - no luck! So, in desperation, I decided to try the oil can pumping method. I was PRAYING that this would work, so I thought that a bit of help from the "force of gravity" may help. :rolleyes:. After a few minutes of using this method, and using quite a bit of fluid in doing this, all "bubbling" stopped! I tightened up the slave cyl bleeder, hopped into car and worked the clutch pedal - wholaaah, fully working clutch!! YAY!
 
what about a stuck clutch disk? Recently had another vehicle that gave me clutch troubles after sitting...didn't want to dis engage, after taking the tranny out, I found the input shaft dry and rusty....last guy didn't grease it, so the clutch plate wouldn't slide to and fro. this particular vehicle is also notorious for being hard to bleed....maybe you had the combination of not a lot of clutch arm movement, accompanied by a stuck disk. has the car been exposed to a lot of moisture lately?
 
interesting, I've started tearing the A arm off in prep to drop the tranny but it sure seems like MY problem is just hydraulics after reading this again. My symptoms are identical and similar problems in the past were solved by bleeding. I wonder how Brett made out. I don't get why it can be fine for months, then go south with no evidence of fluid loss. Maybe an existing bubble finally gets to a certain critical spot?
 
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