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Discussion Starter #1
My new CM eyeballs out to be very close to same total length than my old CM. Do you guys know if these are usually factory set to the application? Should I adjust and take measurements?
 

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They should be the same. The Alfa hydraulic clutch is non adjustable. (yes, I know you can effect a change mechanically by lengthning/shortning the slave push rod or putting a nut in the V-ed out end of the slave piston, but these are desperation remedies, not correct maintenance) The hydraulic clutch is really self adjusting until you end up with a completely worn out clutch assembly. Then it is time to replace the entire clutch assembly and start all over again with your old ,or a new set of hydraulics.

Robert
 

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My new CM eyeballs out to be very close to same total length than my old CM.
Sorry, I don't understand what you are talking about. What dimension of the CM "eyeballs out to be very close to same total length..."? The length of the pushrod? The overall length of the outside of the cylinder?

As vf31rhill wrote above, a hydraulic clutch tends to be forgiving for minor dimensional differences, since the system is designed to self-adjust as the clutch disk wears.
 

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If you mean the pushrod at the master cylinder - it is meant to be set to the specified length and not 'adjusted' in service. I don't know why they made it like that - perhaps so that the same master cylinder/push rod can be used in more than one application by simply varying the push rod length?
 

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I just bought a clutch master from IAP and I planned to adjust the new one to match the dimension "A" (see Eric's drawing above) of the one I am removing (because the old one leaks!).

If I understand Jay's post, getting "A" exactly 5.28 inches is not a requirement.

If anyone wants to advise me differently, I would appreciate the feedback.

Thanks.

jeff
 

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If I understand Jay's post, getting "A" exactly 5.28 inches is not a requirement.
Well, you don't want the piston to max out at either end of its travel. So the pushrod length can't be 4-7/8 or 6". But somewhere around 5-1/4" should work just fine. Adjusting it to the nearest .01" is unnecessary, as the tolerances on the bracket welded to the booster, pedals, etc will be >> .01"

As the pedal is depressed, the rod is going to move X inches, displacing (Pi x D x X) of hydraulic fluid. Whether the clutch MC piston moves those X" in the front, middle, or rear portion of the cylinder's bore doesn't matter a whole lot; all the clutch slave knows is what volume of fluid it receives.
 

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Discussion Starter #7
The fact that the CM has an adjustable rod eludes to the fact that it needs to be 'set'. Plus, the nut was loose on the new unit. Thanks for the info, alfajay and Eric. I replaced mine only because they are cheap, and the the clutch fluid was horribly black. In past experience that was the result of internal seals that broke down...Instead of just bleeding it out again and continue to put up with an off and on again clutch, I decided to replace the CM. The slave was done in 2013, according to the PO, so I'll keep that for now.

Plus now my brake and clutch master match. And that's important, I guess :thumbup:
 
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