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Leaking Clutch Master Cylinder connection after swap

vwengineer

Ready to race!
Location
Switzerland
Hi everybody,

I recently replaced my clutch MC as sometimes the pedal would be stuck on the floor. The new MC went from China but is supposedly a genuine VW made by FTE and it seems so (looks as well built as my old one). The part number is 1KD721388E which is designed for the Chinese market according to ETKA but is supposed to be the same as the 1K0721388AC which is the latest revision for our GTI (in fact all VAG vehicles have the same MC).

Link to the part: https://www.ebay.com/itm/VW-Clutch-Master-Cylinder-1K0721388AC-New-genuine-VW-part/112183511629

Now when I fitted it everything went well, except that the hose allowed some movements back and forth even though it was plugged in and locked. I bled it and went to drive. Everything fine. But after a while the pedal stayed on the floor again (still shifting fine). I assumed the problem was elsewhere. After about 1000km the first gear would be stuck sometimes. I bled again and it was fine again, next 400km same thing. Bled again and went fine again. I also noticed that each time I bled there would be quite a big amount of brake fluid on the floor (I assumed it went from a bad connection between my hose and the bleed screw). But I finally understood today that in fact the connection between the hose and the MC is actually leaking.

The problem is that it seems that VW a 3 different revisions of hoses and connections according to this:



And one gasket kit 1K0798741 (revised) to fit them all (containing cups and o-rings):



Now according to this (http://forums.tdiclub.com/showthread.php?t=399612) the old hose would not fit newer MC and should be replaced (but I have a big big doubt as I cannot find this info on any other forum), but the thing is that my hose seems to have quite a bit of free play with the new MC (did not test on the old one), so not sure if changing the gasket (30$) would help or if I need a new hose.

Does anyone has experience to share about this?
 

vwengineer

Ready to race!
Location
Switzerland

Well I replaced the gaskets but it seems that the brake fluid came from the reservoir and not from the MC which was completely dry :/ no changes in clutch feeling unfortunately. I am too now looking at the bleeder block as the culprit, after that the only element left is the slave cylinder :(
 

beauy46

Go Kart Champion
Location
Orlando FL
Car(s)
2009 TR GTI
I going to replace mine this week as well as well as the ECS Bleeder. Hoping to get a few more months before I bite the bullet and replace Clutch and Slave
 

vwengineer

Ready to race!
Location
Switzerland
I going to replace mine this week as well as well as the ECS Bleeder. Hoping to get a few more months before I bite the bullet and replace Clutch and Slave
Did you already install the ECS bleeder? Did it help? I am about to remove the starter to take a look at the slave cylinder and see if it leaks.
 
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