Ur MB hydraulic clutch adjustment - Page 5

BackintheFold · 25-05-23, 12:25 PM

Final thoughts. If I was doing it again..and had two identical slaves/rods, I would cut one of the rods down by 5mm and try that. It would make fitting easier. It would lower the bite point of the pedal a little bit and provided the clutch plate still disengaged there is no drawback.

If I had two spare rods, I’d cut another down by 10mm. That would make fitting a piece of cake. It would still need to be tested to ensure the clutch disengages, but if it didn’t it would only be a few minutes to swap the 5mm shorter one back in. You only need to bleed it once and shortening the rods makes fitting simple. In fact, I’d be tempted to try the 10mm shorter one first for this reason.

I do wonder if the standard setup has the release bearing being pushed against the clutch fingers. That would explain why the last 5-10 mm of fitting the slave is so difficult-you are operating the clutch with your hand!

sinbin5t · 26-05-23, 08:20 PM

I admire your perseverance with this

BackintheFold · 29-05-23, 01:32 PM

Quote:

Originally Posted by sinbin5t

I admire your perseverance with this

Yup. That’s me. I like to get to the bottom of things, and record the info here in case it helps anyone else (or me again) in the future.

BackintheFold · 04-08-23, 05:17 PM

Ok.
So I got a lathe-ist from eBay to make me up three rods.
The longest is 73mm, and that is now fitted. (The one that came with the Sachs slave is 84mm)
The clutch bite point is mid-range on the clutch pedal. Perfect. Feels similar to my A3 now.

So it is important to get the right rod length. If you change your slave cylinder the length of the rod and cup may change to what you have had.

tractor Dave · 04-08-23, 07:03 PM

Quote:

Originally Posted by BackintheFold

Ok.
So I got a lathe-ist from eBay to make me up three rods.
The longest is 73mm, and that is now fitted.
The clutch bite point is mid-range on the clutch pedal. Perfect. Feels similar to my A3 now.

So it is important to get the right rod length. If you change your slave cylinder the length of the rod and cup may change to what you have had.

Well done! Perseverance has paid off

BackintheFold · 09-08-23, 01:10 PM

Bloody-mindedness more like!

For the record, I estimate that 2.5-3cm on the slave rod would cover the entire range of the clutch-that is, if the bite point is at the floor, using a 2.5-3cm longer slave rod would put the bite at the top of the pedal travel.

I'd suggest that when you remove the old slave, you put the old rod in the old slave piston cup and see how far it sticks out of the top of the slave, effectively with the slave rod extended to its maximum.
Then ensure the replacement slave has the same length protruding. If it is shorter, the bite point will be lower. If it is longer, the bite point will be higher.

None of this will fix a worn out clutch, although I suppose you may be able to get a little bit more out of a clutch by using a shorter rod, if the bite point is at the top of the pedal (resting) and the clutch is slipping, but only if the slave rod was the wrong length originally.

25-05-23, 12:25 PM	#41
BackintheFold Senior Member Classic Audi Club Member Join Date: Feb 2019 Location: Near an MB ur Quattro Posts: 1,188	Final thoughts. If I was doing it again..and had two identical slaves/rods, I would cut one of the rods down by 5mm and try that. It would make fitting easier. It would lower the bite point of the pedal a little bit and provided the clutch plate still disengaged there is no drawback. If I had two spare rods, I’d cut another down by 10mm. That would make fitting a piece of cake. It would still need to be tested to ensure the clutch disengages, but if it didn’t it would only be a few minutes to swap the 5mm shorter one back in. You only need to bleed it once and shortening the rods makes fitting simple. In fact, I’d be tempted to try the 10mm shorter one first for this reason. I do wonder if the standard setup has the release bearing being pushed against the clutch fingers. That would explain why the last 5-10 mm of fitting the slave is so difficult-you are operating the clutch with your hand! __________________ 2006 A3 (daily drive) 1987 MB ur Last edited by BackintheFold; 25-05-23 at 12:27 PM.

04-08-23, 05:17 PM	#44
BackintheFold Senior Member Classic Audi Club Member Join Date: Feb 2019 Location: Near an MB ur Quattro Posts: 1,188	Ok. So I got a lathe-ist from eBay to make me up three rods. The longest is 73mm, and that is now fitted. (The one that came with the Sachs slave is 84mm) The clutch bite point is mid-range on the clutch pedal. Perfect. Feels similar to my A3 now. So it is important to get the right rod length. If you change your slave cylinder the length of the rod and cup may change to what you have had. __________________ 2006 A3 (daily drive) 1987 MB ur Last edited by BackintheFold; 09-08-23 at 01:11 PM.

09-08-23, 01:10 PM	#46
BackintheFold Senior Member Classic Audi Club Member Join Date: Feb 2019 Location: Near an MB ur Quattro Posts: 1,188	Bloody-mindedness more like! For the record, I estimate that 2.5-3cm on the slave rod would cover the entire range of the clutch-that is, if the bite point is at the floor, using a 2.5-3cm longer slave rod would put the bite at the top of the pedal travel. I'd suggest that when you remove the old slave, you put the old rod in the old slave piston cup and see how far it sticks out of the top of the slave, effectively with the slave rod extended to its maximum. Then ensure the replacement slave has the same length protruding. If it is shorter, the bite point will be lower. If it is longer, the bite point will be higher. None of this will fix a worn out clutch, although I suppose you may be able to get a little bit more out of a clutch by using a shorter rod, if the bite point is at the top of the pedal (resting) and the clutch is slipping, but only if the slave rod was the wrong length originally. __________________ 2006 A3 (daily drive) 1987 MB ur Last edited by BackintheFold; 17-08-23 at 10:47 AM.

26-05-23, 08:20 PM	#42
sinbin5t 4 ring whore! Classic Audi Club Member Join Date: Jan 2010 Location: Where a spike points skywards Posts: 12,960	I admire your perseverance with this