Clutch master cylinder

[tennentsfan]

lads having a few problems with the clucth on my 1.9 tdi awx .Changed the master cylinder a couple of months ago and i tihink its failing again . Clutch pedal wont come off floor tried bleeding manually and theres no build up of pressure . diconnected the pipe at the slave cylinder and connected a pressure bleeder and theres no fluid coming through . when i changed it originally i never pressure bled it . Would this be why this one is goosed so soon ?
cheers kieran

[martin1810]

Are you sure the pipe is not damaged/blocked.

[tennentsfan]

Eh no but the last master cylinder didn't last long either and I'm thinking that's down to it not been bled with a pressure bleeder . But I'm not sure on thy either ?

[OddBallBoy]

Maybe too simplistic a suggestion but might be worth a look to check the pedal itself? Friend of mine had a Golf in with clutch pedal on the floor, no resistance to it when you pulled it up or down, apart from at one point when it locked solid in the down position. He hadn't looked at it properly but had been thinking maybe master/slave cylinder but I took a look and it turned out the bracket welded onto the clutch arm for the actuator rod (probably not the right name, basically the rod the clutch pedal arm operates on) end to clip into had broken. (When it locked solid, it was because the rod end jammed in what was left of the bracket) Apparently a common'ish problem with the Golfs and there is a lot of component sharing so wouldn't be surprised if the clutch pedal arm is the same on the Passat.

It would have been possible to bend the bracket back and re-weld but we went for a new pedal. Seem to recall about £25 for a new one from TPS - when you looked at it, it only had a few spot welds and could easily be made a lot stronger from new with just a few more spots.

Hope that helps, that it turns out to be that simple!

[tennentsfan]

Would love to say it was that simple but it's not unfortunately .

[tennentsfan]

So I checked all the pipes weren't blocked and fitted a new clutch master cylinder again . A week on and the bite is very close to the floor again and clutch is very light . Anyone ?

[tennentsfan]

Calling the god of this forum !!! Are u there crasher ?????

[stonedagain]

So I checked all the pipes weren't blocked and fitted a new clutch master cylinder again . A week on and the bite is very close to the floor again and clutch is very light . Anyone ?

Check the pipe at the slave cylinder, there is an alloy adapter on the end of the pipe, that is held into the slave cylinder by a clip. Mine had been damaged by whoever changed the clutch before I bought the car. It had a deep gouge in it at the point where it sits inside an 'o' ring in the cylinder, presumably allowing air to be drawn in when the clutch pedal is released. I had similar symptoms as you have, but strangely the fluid didn't leak out until a year or so later. I suspect that depressing the pedal maybe compressed the seal under pressure hence no leak, then when releasing the pedal the seal relaxed, allowing air to be drawn in. Replacing the adapter cured it, BUT..........you can't buy it seperately, it only comes with the complete pipe at over £60!

[tennentsfan]

Would this cause it to eat master cylinders ? That's 2 in the last 3 month and one in the last week . There was a issue with the slave cylinder before leaking fluid into the bell housing . Would this possibly be something to do with it ? Has it rotted the thrust bearing ? Would this allow the fork to move ? When I done my skoda clutch last week the fork was there u could see it quite clearly with the passat it's a good 2 - 2/12 inch inside the bell housing . It's driving me nuts now but there doesn't seem to be much info on net about it either .
Thanks in anticipation
Kieran

[caldirun]

Would this cause it to eat master cylinders ? That's 2 in the last 3 month and one in the last week . There was a issue with the slave cylinder before leaking fluid into the bell housing . Would this possibly be something to do with it ? Has it rotted the thrust bearing ? Would this allow the fork to move ? When I done my skoda clutch last week the fork was there u could see it quite clearly with the passat it's a good 2 - 2/12 inch inside the bell housing . It's driving me nuts now but there doesn't seem to be much info on net about it either .
Thanks in anticipation
Kieran

I would strip the master cylinder and find the reason its not working, could be excessive movement due to dislocated/bent release fork or collapsed thrust bearing.

[tennentsfan]

Whipped everything out tonight .
Slave cylinder seals are worn at one side and the it's worn inside aswell .
Master cylinder buggered again .
Spoke to a Audi specialist reckons the flywheel which has play in it and is rubbing against slave eating it out and knackering the master .
Does this sound about right ?

[martin1810]

Whipped everything out tonight .
Slave cylinder seals are worn at one side and the it's worn inside aswell .
Master cylinder buggered again .
Spoke to a Audi specialist reckons the flywheel which has play in it and is rubbing against slave eating it out and knackering the master .
Does this sound about right ?

The cause may just be age and wear. Looks like slave is letting air in which rises to the master reducing lubrication and wearing that. I would fit new slave, pipe and master and see how things go. After that it's a case of gearbox off to have a look.

[tennentsfan]

It had only had a slave a couple of months prior . Anyway new dmf and clutch and New slave and master and problem is fixed .