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Clutch problems...please advise...

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Old 05-15-2012, 12:05 PM
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Vonov
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Default Clutch problems...please advise...

Rear main seal was leaking at the rate of about ten drops of oil per minute, so I decided to replace it. I was amazed at how nice the car is to work on (50k miles, 1981), everything seems logically laid out, and relatively easy to access. (These cars really seduce you, don't they?) Since the clutch disc was oil soaked, I replaced that as well. I did not crack open the clutch hydraulics, seeing no need to do so, as it was working fine prior to replacement of the the seal. I've become VERY proficient at taking the car apart, as I've now had it apart and back together THREE TIMES over the past week. The car starts in neutral, but will not go into any gear; to get the car into gear, it has to be started in gear. I noticed the plastic ball cup piece at the top of the clutch lever in the bellhousing had disintegrated, so I replaced that, with no difference.

Can someone please advise me as to what areas I should be looking at to solve the problem? I've tried bleeding the clutch hydraulics as well...it acts as though there's a check valve in there somewhere, as the power bleeder barely passes fluid into the system, even under ten PSI.

(BTW, for those contemplating a clutch replacement, GearWrench's new pivoting head ratchet-type box wrench is the bomb for those upper TT bolts on the inside of the TT. Lock the head to break loose the bolts, and then unlock it to use the wrench in a piston motion in conjunction with the ratcheting feature of the wrench to back the bolts out once they're loose.)
Old 05-15-2012, 12:10 PM
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Lizard928
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You must have preload on the master cylinder. Adjust the clutch master in cockpit to release.
Also adjust the intermediate plate for proper release and your problem will likely go away.
Old 05-15-2012, 12:14 PM
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Mrmerlin
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how old are the clutch hydraulics?
if original you should replace the whole system including the flex hose,
do a search for modifying the master cylinder,
you could remove the old piston and spring and swap over the seal then fit to the new MC , the flex hose swell over time this may be the issue, the slaves will leak,

the pushrod adjuster at the MC may need to be adjusted you should see about 4Mm of pedal travel before the rod moves the piston
Old 05-15-2012, 09:12 PM
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Vonov
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Thanks for the quick replies.

Still struggling with it, going to try power bleeding from the slave end before replacing master...if that becomes necessary, is it necessary to bench bleed master? Any other tips pertaining to replacing the master?

Thanks in advance, you folks are great.
Old 05-16-2012, 10:34 AM
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Mrmerlin
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replace the flex hose when you open the system
as well as fitting a new blue hose Roger sells new Brembo blue hose
Old 05-16-2012, 12:44 PM
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Lizard928
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Don't replace anything yet!
Remove the preload on the master and adj the intermediate plate!!!
Old 05-16-2012, 12:51 PM
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Lizard928
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To remove preload,
Go under dash to clutch pedal,
You will see a rod which connects the pedal to the master.
It has a 13mm nut on it, back this off and then thread the rod more into the block.
Do this until there is a tiny bit of freeplay in the rod to master.

To adjust the int plate,
Drop the lower bell housing cover (what the slave bolts to),
Then locate the 3 adjustment tabs on the intermediate plate, adj towards the engine leaving about a 1mm gap.
Pry the release arm back with a rachet strap and turn crank with a 27mm socket on front of crank to access all 3.
Adjust these down with as little tolerance as required to allow free movement of the discs ( you can reach up and turn the stub shaft by hand, or rotate engine and ensure discs don't turn.

Once this is done report back.
You needn't do anything to the rest of the system!!!
Old 05-22-2012, 09:46 PM
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Vonov
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Thank you, Lizard, (and all) for the detailed instructions...now I have another problem. My best friend has a (very much minority) business partner who sort of wormed his way into partnership at my friend's shop. My friend told me to leave my car on the lift (there are three others in the shop), and we would button it up in the morning. The partner likes to play the "Big Cheese", and when he came in, without bothering to ask me (I was in the front office at the time) if the car was safe to move, took it upon himself to take the car off the lift and rolled it outside...with the transaxle unbolted from the mounts and moved to the rear four inches. I'm hoping when this weekend rolls around, and I get the car back on the lift, I won't find any damage. What a prize jerk.
Old 05-22-2012, 10:36 PM
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Dick move right there but you may be ok. Only way to know is get it back in the air.
Old 05-27-2012, 03:57 AM
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Huzzah!!! It's fixed, and no damage due to unscheduled move, thanks to torque tube still in place. The intermediate plate adjustment was indeed what was needed.
Many thanks to all; the clutch works better than it ever has, and the trans shifts like velvet (it was a little balky before, especially when cold), which leads me to suspect it needed the adjustment all along.

Old 05-27-2012, 04:17 AM
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Podguy
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One of the best ways of bleeding the clutch is to disconnect the slave from the bell housing and push the rod back into the slave cylinder a few times. If the clutch pedal is not fully cleared then it will not allow you to bleed the clutch this way.

Glad you got your problem fixed.
Old 05-27-2012, 01:13 PM
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Lizard928
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Thank you for posting the final results on this!

And glad you adjusted before starting to replace parts.



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