Mk6 6 speed slave cylinder

Over the weekend I change the clutch, flywheel and slave cylinder on a mk6 Jetta tdi. Car has around 56k on it. The clutch hydro kept losing fluid and pressure. I guess there isn’t much out there about this problem yet so I figured I’d post this. The internal slave was leaking badly by the time he brought the car to me. For anyone else have problems with the 6 speed losing pressure/fluid it is likely the internal slave. Job wasn’t too too bad in all.

all it is, is a few orings and a piston.
easily rebuildable.
for futur note, put a block of wood down underneath the pedal. keeps it from traveling pasts its normal range and from putting those seals into the muck and rust in the cylinder.
change your fluid often and this wont be a big deal.

Rebuild the slave?

Most of these cars that are having the problem that I see are ones that sat waiting for VW to do the emissions update. Not saying all will do it. Trans has to come out to change the slave regardless.

Mongler98 said:

for futur note, put a block of wood down underneath the pedal. keeps it from traveling pasts its normal range and from putting those seals into the muck and rust in the cylinder.

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uh, plastic doesn't rust
and clutch master cylinder sees full stroke every time, brake master cylinder is what doesn't see full stroke except while bleeding

please no more bad info

I would hate to rebuild a slave clutch cylinder to find its leaking when all fitted... As above, plastic doesnt rust but there are alloy ones about as well...

there are other parts that are metal, some steel, some not, rust happens if you don't change the fluid, even if the lines are copper, you still get that green oxide and it sits down at the bottom of the throw that does not get nearly as much use, when you flush it, it stirs it up and it gets into the seals and they wear down.
change the fluid properly often enough and it's never a real problem but don't and i don't care what its made of, you will have sediment and what not down low just sitting there, waiting for you to make your move, then BAM! ITS LEAK TOWN BABY
and btw, its really easy to test them with a hydraulic jack and a vice and a few fittings (if you have those tools)

Just for reference mongler. The only part that is steel is that throw out bearing section. The lines are all hard plastic and unions are plastics bleeder is plastic. The problem is the cars sitting and waiting at the vw graveyards for the emissions fix....o rings Seem to dry out and end up leaking over time.

I only posted this for any CR 6 speed owners that are have problems with slave pressure or losing fluid.....

Do not bother with Mongler, he has no idea what he is talking about.

The 6sp internal slave cylinder is a pretty common failure point. Remember, VAG was using these in other cars long before they sold them here with a TDI. The GTIs, GLIs, NB Turbo S, TT, etc. all used it more than a half decade before the 2009 TDIs got them. So this issue was pretty well known.

Thanks oilhammer. Much appreciated info.

I do not think it is quite an epidemic level, but like so many things on the earlier cars that just rarely failed (like the clutch hydraulics), we tend to have been spoiled. I have never, ever, seen even one bad slave on a 5sp 02J, which would be super easy to replace. But I have probably seen about 30 leakers on the 6sp.

There are other cars that use the internal type as well (like many Fords).

If only things were so simple like the 02j. I could tear one of those apart swap new gear sets in and reseal the case in about 40 mins in one of those. Miss those days.

Yourbuddysatin said:

If only things were so simple like the 02j. I could tear one of those apart swap new gear sets in and reseal the case in about 40 mins in one of those. Miss those days.

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Some of us are still enjoying those days.

My mk4 has been under construction for over 2 years now. I’m sure once it’s back on the road I’ll be back at ripping it down every so often.

Yourbuddysatin said:

Just for reference mongler. The only part that is steel is that throw out bearing section. The lines are all hard plastic and unions are plastics bleeder is plastic. The problem is the cars sitting and waiting at the vw graveyards for the emissions fix....o rings Seem to dry out and end up leaking over time.

I only posted this for any CR 6 speed owners that are have problems with slave pressure or losing fluid.....

Click to expand...

well, ill be a sonofagun
open mouth, insert foot,
dang these new cars and they finest Chinese Plasticium parts.

O.H., don't give up on me yet, Thanks Satin, your my buddy.......