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997.2 PDK bleeder screw slight leak?

As a side note, That cutaway doesn't show how an internal seal would fail? The entire of that section of the gearbox (odd and even gear rails) is constantly lubricated/submerged in oil. I'd understand if it was in the clutch section where oil pressures are more vital.

Maybe it stops air locks when initially servicing the PDK system from build? Maybe they're built up on a jig, pre serviced and a bleed plug helps when setting levels before installation in a car on the production line? Or maybe its a boroscope port to make sure everythings lined up after build up?


The OPC "internal seal failure" sounds like a very safe "we don't want to get involved with that" answer. I know volkswagen don't really go any deeper than changing clutch packs, drive shaft seals (common fault) and mechatronic units.
 
Just to clarify, I did not replace the bleeder screw even though I was able to buy a new one, see snaps. NB there is a hole down the middle. I just smeared sealant around top and sides of the existing bleeder screw. I had been told if I remove it something might fall off inside the gearbox.
 

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Forgot to say I did email ZF earlier this week about the purpose of the bleeder screw. They refused to comment as they said it was a Porsche issue. Oh well, not really surprised they have to defer to Porsche.
 
Yeah i'm sure i read someone mention something about possibly dislodging something internally. (Although i think its highly unlikely)


Judging by the shape and size of the bolt, It's got quite a large plain portion which makes me think this is the "internal" seal people are talking about.

Does that central hole look to run the full length of the bolt? This is what i think the "bleed" part of it is. So theoretically it's just cracking it off to start a bleed procedure, but the bolt shank remains sealed (against the internal seal they mention)

I don't see a reason why the external seal (the rubber bit under the head) shouldn't function as a serviceable seal for years to come. But maybe after nearly 10 years of heat and pressure cycles starts to weep.

In which case, your cap seal will probably suffice. I'm gonna look into replacing it.
 
Yes the screw is hollow the full length. Very strange. NB the yellow sealing type tape which is on most of the length of the thread of the screw. It got a bit grubby with the OPC people handling it when I asked them to examine it.
 
Yeah, so as i thought loosening it slightly would allow it to be bled, Then re-torqued onto the rubber seal under the head.

The yellow tape will be a thread lock.


I've noted your part number, hopefully get down next week (cars at a unit with a ramp). See what i find out!....
 
i recently noticed a leak from my PDK. I used a small camera and figured out the 2 places its leaking from. No clue what to do regarding the leak besides replace the PDK
using pictures found online i have marked the leaking area

driver side vent valve (circled)
2u5t92t.jpg


passenger side its leaking slightly from the blue cap like thing on top right of pic
2ujt9ia.jpg


as there is hardly any info about the PDK online, i cant figure out what those 2 parts from which its leaking and their purpose.

no error codes on piwis, pdk shifts are perfectly fine. no other error codes whatsoever on the car. Just the undertray and transmission housing with oil splatter.

2010 C2s with 60k kms
 
Hi Mate,

Are you certain its leaking from those points? The blue cap is the filler right?

I'd imagine if you call porsche there might be an o-ring replacement for the filler port and maybe the breather.


It does tend to blow around abit under there, so you may have to clean it all off and run it back up to temperature to observe further. The bleeder screw on mine was the culprit, But due to the oil blowing around abit it looked like something else! - Even an indy had replaced the sump pan assuming it was that leaking and it wasn't!

I replaced the bleed screw on mine the other week....so far so good
 
The blue cap is not the filler. No idea what it is. The cap just turns, I could not get it to open. Anyway it's a very small leak there, almost like just a sweat.

The main leak is from the vent valve I have circled in blue. It's for sure from there. As per Porsche none of those are replaceable parts so no idea what do do. I have cleaned it up as best as possible in the limited room there. Will monitor regularly and see.
 
Im not totally sure but there will be 2 breathers , one for the clutch fluid chamber and one for the gear oil chamber .. the blue one might be one of the 2 breathers in other words .

Every gearbox .. manual or auto will have a breather to vent / allow in air .

They dont leak though ... the oil lvl is no where near them so if you do have a leak from there then its a little worrying .

i know very little about these boxes but i do know there have been a few issues .

It might be worth getting it looked at .. a sweat is no big deal but it seems to me you actually have a leak .
 
Possible the blue cap is the pdk clutch fluid breather as the clutch fluid is towards the back of the transmission. It's merely a light sweat there.

It's the breather for the differential that's leaking especially under hard driving or when it heats up more than normal.

Absolutely no transmission issues, no error codes, no warnings. Shifts are quick and smooth.
 
More information about that screw?

I was changing the transmission fluid in my PDK and removed this screw by mistake. There was a mislabeled picture online.

Anyone figure out what the screw is about? Do things fall into the transmission if its removed?

I stuck a little camera in there to take a picture. Definitely looks like there could have been something filling that gap at one point.
 

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I started this post back in 2017.
The part is still in my glove compartment.
Thoughts were that it is a type of internal seal.
I didn't want to chance replacing the original.
No issues so far after 4 years and about 35k.
 
Sorry to bring up an old topic here, but I have a sweating PDK gearbox on a 981. I believe that much like Cy00 that this is coming from the blue bleeder valve on the top of the gearbox.

Originally I thought it was coming from one of the old cooler lines, but I have cleaned them up and within 1k miles added since doing this I see no new sweating in this area. Hence, does this bleeder valve only sweat under hard driving? Someone posted on Rennlist that this may be the case?

Cy00 if you still have the car, did you get it sorted (new pdk), or is the car still running ok?

Any other feedback welcome. Photo attached and vehicle to go in to local OPC to investigate, but I don't want the standard response of a new box required :sad: :sad:
 
The blue cap is the filler point.
I think you were right that it only weeps under extreme pressures.
My weeping was noticed a few weeks after I first got my car and I had been fully exploring the red line. It was noticed when in with the local OPC to get the 6 year clutch oil change (2 years late) and I was told new gear box was required as no fix was available.
I decided to just keep an eye on it. That was back in early 2017 and 35k miles later the car is driving great.
The issue has always been a constant annoyance but I live with it.
Car is driving grate.
Regards all.
 

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