Okay, I've checked | Posts 16+

hi,
In my Trapo machine, the ...261 receiver cylinder is installed.
Can someone please check if this receiver cylinder has actually been installed?
My birth year is 1999, my graduation year is 2000 (high school diploma: AJT, university degree: DUJ).
According to the catalog from 2003, the part number should be ... 261 H.

It would be better to have pictures of both intake manifolds for a visual comparison.

You're welcome.

Hi Leo,

ulf wrote:

... Do you have any ideas or suggestions as to where the "variations" in the clutch engagement point might originate in 6-speed transmissions (with the slave cylinder located on the release bearing)? ...

Unfortunately, I'm not a fortune teller .

leo_b wrote:

hi, In my Trapo machine, the ...261 receiver cylinder is installed. ... According to the catalog from 2003, the part number should be ... 261 H.

Both are possible. I also have different information.
For safety, please check the online catalog at ZF-Sachs. You can correctly match the cylinders there.

hi,
Both intake manifolds are technically identical! (part numbers 1J0 721 261 D & H)
According to the manufacturer's specifications.

Okay, who's going to prove me wrong?

Hi Leo,

leo_b wrote:

Okay, who's going to prove me wrong?

According to a ZF Sachs employee, the cylinders differ in the pressure spring and the valve lifter.
According to the Sachs electronic catalog, they are supposedly the same.
The VW catalog also claims that they are different.

I haven't become any smarter either. "However, in my case, the slipping issue disappeared after replacing the cylinder."

By the way, this doesn't only apply to the 74kW engines. I know enough drivers with 96 + 110kw engines who have the same problem.
But they still have some additional reserves beyond the nominal maximum of the input torque, which is 350 Nm:
96 kW = 310 Nm
110 kW = 320 Nm
117 kW (Ibiza Cupra) = 330 Nm, which on paper still provides double the reserve (20 Nm) compared to the AXR (10 Nm).

By the way, according to the documentation, the 6-speed transmissions use a hydraulic release bearing instead of an external clutch release cylinder and release lever.

But, in the 96 + 110 kW drivers you know, does the clutch also slip noticeably early on, perhaps? Assembly error?

Regarding this issue: The clutches are smoking, and it's not stopping - whether it's the 130 model or the 150 model, but mostly the 150 model.

For me, it continues.
I will have the opportunity to visually inspect both sensor cylinders next week.
Both will be measured and photographed in detail.

I'm curious to see the translation too.

Hi Leo,

Hi,

After having a full four weeks of peace, the clutch started acting up again. So, in desperation, I ordered the slave cylinder. To my surprise, it was a different part. The new one has a much longer, two-piece pushrod. Since there's a joint in the middle of the rod, I assume it's designed to keep the vertical movement away from the piston. I haven't seen any other modifications that might be related to my issue.
And as often happens, I discovered that the old cylinder was leaking. So, I would have ended up with wet feet in just a few weeks.
During the bleeding process, the final disaster occurred... the expansion tank is drawing air... right at the threaded hole for the clutch cylinder connection. So, I had to replace that one too. Unfortunately, it had to be ordered. Then, on Friday, we'll continue...

... I'll definitely take another look at that.

Hi Leo,

Okay.
I also had a new clutch installed in my AXR today because it started slipping after 137,000 km. The receiver cylinder was still sealed and remains so.

It actually started right from the beginning, when I bought it from the VAG dealer. The clutch also started slipping very early on. In addition, the pedal was very difficult to press down throughout its entire range of motion.

The new (Sachs standard version) makes the pedal feel very smooth. However, the clutch now disengages very late, even though the slave cylinder (1J0 721 261 D) remains the same. However, this contradicts Bertil's assumption that the sliding might be a problem related to the cylinder.
Okay, let's see how it holds up for the next 100,000 kilometers.

Hati wrote:

... The new (Sachs standard version) makes the pedaling incredibly smooth.

Just like with mine... after 8,000 km, the next clutch was already scrap. After approximately 3,000 to 4,000 kilometers, the old conditions returned.

Quote:

... However, this contradicts Bertil's assumption that the sliding might be a problem related to the cylinder. ...

That's exactly what I thought too... unfortunately, it seems that a hydraulic clutch doesn't function quite as trivially as one might expect...

After experiencing the third clutch slipping again after only 10-15,000 km, I started to have some serious concerns.
Initially, I suspected the receiver cylinder. Unfortunately, it turned out to be incorrect after a few weeks.
"I've now replaced the master cylinder, and the third clutch, which used to slip, can no longer be made to slip. Even with a tuning chip, I have to actively try to make it slip (but it is possible). Unfortunately, the clutch seems to have suffered some damage and it's slightly glazed." However, a noticeable improvement in the situation can be felt.
Suddenly, a VW workshop also wants to recall having seen a similar type of damage before...

P.S.: The last clutch was driven completely without any clutch pedal usage!

Quote:

Hati wrote the following:: ... The new (Sachs standard version) makes the pedaling incredibly smooth. Just like with mine... after 8,000 km, the next clutch was already scrap. After approximately 3-4 thousand kilometers, the old conditions returned.

I imagine it like this: If the clutch becomes difficult to depress after a few thousand kilometers, it's often a sign that the clutch disc is worn out. Due to this circumstance, the pressure plate's diaphragm spring remains extended in the engaged state, so that when disengaging, it no longer passes its neutral point (where spring force decreases).

The cause is likely to be found in the hydraulic system, possibly due to blockages in the sender or receiver cylinder, or the follow-up hole may not always be fully opened, which can result in incomplete engagement.
If the clutch starts to slip gradually, it will naturally wear out within a few thousand kilometers.

The cause of different engagement points in a clutch, as long as it's reasonably mechanically sound, is almost always found in its actuation system, and not...
within the clutch itself.

BM wrote:

... I imagine it like this: If the clutch becomes difficult to depress after a few thousand kilometers, it's often a sign that the clutch disc is worn out. Due to this circumstance, the diaphragm spring of the clutch pressure plate remains extended in the engaged state, so that when disengaging, it no longer passes its inflection point (where the spring force decreases).

Unfortunately, all of my clutch plates were the same thickness, except for two, which were 2/10mm thicker. Whether new or old.
By the way, the spring force of the pressure plate is strongly counteracted by a dead-point spring on the pedal in the upper half, which severely distorts the pedal feel. Therefore, I no longer (or not much anymore) pay attention to the pedal forces with the G4 system.

Quote:

...or the pilot hole may not always be properly cleared, which can result in incomplete engagement.

After successfully replacing the donor, I share the same opinion.
By the way, the new sensor is completely different from the old one.

Quote:

If the clutch starts to slip gradually, it will naturally wear out within a few thousand kilometers.

That's the joke... it didn't wear down, but rather "only" became glazed while maintaining the full original coating thickness.

Quote:

The cause of different engagement points in a clutch, as long as it's reasonably mechanically sound, is almost always found in its actuation system, and not... in the clutch itself.

That's exactly why the thread title is what it is. But many people don't want to accept that. Neither does my workshop... yet... but it does now .
I even replaced the clutch, pressure plate, and dual-mass flywheel every time... so a completely new system. Fortunately, the third system didn't cost me anything.

Quote:

Incidentally, the spring force of the pressure plate is strongly counteracted by a dead-point spring on the pedal in the upper half. It severely distorts the pedal feel.

Not quite, it's only meant to have a supportive effect.
What could be possible is that VW may not have perfectly calibrated the spring force of the Belleville washer in the pressure plate, so that a proper reversal of force may not occur there for very long (even with very little wear). (See a technical manual for automobiles or...).

Otherwise, we agree.

... I have come to the same conclusions.
and I can only agree with that.

Okay, so, who has a master cylinder for me?


Hi Leo,

Bertil wrote:

. And as often happens, I discovered that the old cylinder was leaking. So, I would have ended up with wet feet in just a few weeks. During the bleeding process, the final disaster occurred... the expansion tank is drawing air... right at the threaded hole for the clutch cylinder.

It could also be a reason for the wandering print point... I once had a leak, but it didn't cause a slipping clutch; instead, it resulted in a wandering engagement point.

I wouldn't have noticed the air leak; I always bleed the brakes using pressure, so I would have only seen any escaping brake fluid.