What to measure when adjusting clutch pedal bolt?

You want about an inch of play AT THE PEDAL regardless of anything else, unless it is a very weird design.

A self adjusting one should do it automatically when you put your foot under the clutch pedal and pull up instead of pushing down.You didn't mention make and model of the car so that is not for sure, but most of them are like that.

Such things can be found out online sometimes. There may be a youtube on how to do it, or you might get lucky and find a manual for it. Sometimes auto parts stores also put out the information.

The rod (bolt) needs to be adjusted so that there is about 0.1" clearance between the end of the rod and the clutch master cylinder piston with the pedal 'up' (not pressing it). You can't see the piston or where the rod contacts it, so you have to do it by feel. Push the pedal gently by hand* until the space is taken up. If you can't feel any space, you might have it too tight. Back the rod out of the master cylinder until the clearance is obvious and then gradually extend it. When it's correct, tighten the jamb nut to keep it in place.

The idea is that the clutch master cylinder has to be able to 'relax' all the way rearward when not pushing on the clutch. At the last point in it's travel, the piston opens up the port to the fluid reservoir and lets fluid in to make up for leakage.

*Feeling the rod clearance is easier by hand. Your foot isn't sensitive enough to judge the small amount of play.

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Paul Hovnanian     mailto:Paul@Hovnanian.com 
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Never put off till run-time what you can do at compile-time. -- D. Gries

It's not my vehicle, and the "feel" stinks no matter what position it's in.

What changes is that it engages early, or late, but not in a way that I like either way.

So I can't adjust it by feel because there is no position that feels right to me.

Therefore, I just want to adjust it by the book.

If only I knew what to measure as I think it's for a millimeter or two of 'slop' between the rounded end of the bolt and the master cylinder piston cup.

But I don't feel that slop in any case. And I don't know where to measure it either.

Hence the question.

You might have a sprung (defective) pressure plate. Been known to happen.

The feel doesn't stink just because *you* don't like it.

It will either take up early or it will take up late. It cannot do both, either one or the other. Clutches simply cannot work the way you are imagining they do.

This is a situation where pedancy will stuff you up right royally.

Do you have the *book* handy? If not, you are lost.

The method used to adjust a clutch will depend entirely on the mechanism employed. There are 3 general possibilities in common use; hydraulic, cable, mechanical linkage. Each of those will have variants and the differences will make a difference to how and where it is adjusted.

Best you get to it and RTFM.

If you can't feel the play, it doesn't have any.

If it is meant to have play, then fix it so it does.

For master cylinder clearance - At the pedal pushrod in most cases. For slave cylinder clearance - at the slave cylinder in most cases.

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Xeno

I think the problem is mostly that I don't feel any free play.

Here's a screenshot of the manual process.

And the spec.

But you have to *feel* that slop in order to measure it. I don't know why I don't feel any slop.

Normally, there should be about 1/2 inch between the resting position of the pedal annd its thrust position (completey up. This is for preventing continuous fricton inside the clutch.

The Troll is back. Please don't feed the troll.

Please advise the troll to do the following:

a) Purchase and read the owner's manual for the vehicle in question. b) Re-read the relevant sections of the manual until well understood (unlik ely, even if possible). c) Then, find a competent mechanic to execute the proper procedure utilizin g the correct means and methods, with the correct parts.

None of the above is likely to happen, so this waste of air and water would prefer to take its detritus into an electronics group so as to discuss clu tch bolts. How apt!

There are no 'generic' clutches. What is correct for an old VW with a clut ch cable will not be correct for a BMW with a hydraulic clutch, nor a DSG w ith dual electronic clutches.

As it has carefully concealed the age, make and model involved, it has deci ded to waste the time of actual people by providing deliberately misleading , limited and incomplete information as a means to start on a 200+ post thr ead by splitting more and more hairs.

If the rest of you feel that this is a productive use of your time, have at !

Peter Wieck Melrose Park, PA

It is actually there to guarantee that the piston can fully return to its stop (circlip usually) and fully uncover the compensating port allowing pressure in the slave cylinder and lines to release and fluid to return to the master cylinder reservoir. If this does not happen, the system may pump up and slave cylinder will not return thus not applying or only partially applying the clutch. The most common symptom of this, apart from a lack of pedal clearance, is a clutch that slips.

Also, it is wise not to dick with the pedal height adjustment as you may end up with more MC travel than previously existed. That can result in a torn or damaged primary seal if the piston is now traveling over an unworn part of the cylinder or, worse, a part of the cylinder that has corrosion buildup on the unworn part.

Frankly, if Roger needs to find out how to do the job from advice here, he'd be well advised to hand the task over to someone with a clue. This is basic stuff, hardly high tech, and he's *struggling*.

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Xeno

Here's a screenshot of the manual process.

And the spec.

The measurement is about 160 mm in the resting position.

Pushing gently with my finger, I can measure the lower position.

This #2 measurement seemed to be about 5mm but my only confusion left is that these two things seem to be the same thing: A. Pedal freeplay B. Pushrod play

The reason they seem to be the same thing is that, with one finger on the pedal, you can push the pedal down about 5mm until you hear and feel the pushrod hit the master cylinder piston cup.

I can't yet distinguish between the two (freeplay & pushrod play) with my finger or measurement at the top of the rubber part of the pedal position.

Clare Snyder posted for all of us...

Sharp as a marble aye?

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Tekkie

Too much free play causes the clutch pedal to "bounce". e.g. The difference between the pedal at the up stop and start of engagement.

Push rod play is contact to resistance.

A bad throwout bearing will totally mess up the feel you expect. It will feel sloppy.