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Discussion Starter · #1 ·
I must be doing something wrong when installing new master cylinder.

I'm using NooNoo's excellent DIY

My first master cylinder (new from JPGroup) failed during bleeding. The plastic collar is broken. Not sue if that was how I got it or if pressure during bleeding made it break.
Gas Auto part Circle Metal Cylinder


So I bought a new one from Luk.
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Installed it yesterday and noticed that even with the metal clip pushed all the way in, the elbow part slides up and down 1-2mm. Doesn't matter how hard I try to push the elbow up into the master cylinder connector, it doesn't seem to click in & always has that 1-2mm up down movement. Actual clutch pedal assembly is bolted into place. Even got 3 new self-locking nuts!
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When bleeding, not surprisingly, it leaks at this join. Any ideas would be appreciated.

Northpole, no it wasn't broken to start with. Pedal worked perfectly well. Even bled the system after the new clutch was installed. I stupidly decided to replace it as part of a new clutch job. Been regretting this for 6 weeks (takes a while for new parts to come from Latvia to Australia).
 

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must be a seal missing as stated above...

must be number 7 in the picture missing.. if you've got that and it's still leaking than it must be a problem with either the pipe itself, or the new master cylinder.
 

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Discussion Starter · #4 ·
Thanks, yes the seal is in place.

Other than re-fitting the old master cylinder, I'm not really sure where to go.

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than the supplied luk is defective... as i think back to when i did mine when pushing on the pipe you should feel it lock into the housing... than you push down the circlip( locking clip) that should be the end of it leaking... but if you don't feel it lock itself in place than it's faulty.
 

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Discussion Starter · #7 ·
Thank you to all. Adam, is there 2 seals? One on the elbow (#7) in Northpole's diagram and second #28 in parts diagram below?
28 02F 141 143 A o-ring 9,25X6,07X1,78
28A 02F 141 143 A o-ring 9,25X6,07X1,78
(28A) 1K0 721 741 o-ring

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Old seal looks the right size, internal seal to the master good?
it's why i said the new one must be faulty as it should have the internal seal installed... they never come separate and i had to change them twice on my own car, and did 4 others that weren't mine... and only once did i have a leak like that ( cheap Chinese copy bought by someone else) but he ended up buying one from eurocarparts and that didn't leak.
 

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Interesting my OH's Caddy was leaking on a totally stock OEM setup - hadn't been disturbed AFAIK. May of had a clutch.

Anyway, started to leak and I padded out the OEM seal on the pipe with a rubber o-ring behind it. Used it to 'push' the OEM seal further towards the end and it sealed up fine.

Pure pikey but it's held for 20k sooooo.
 

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Discussion Starter · #11 ·
Thanks for your patience. I ripped apart the master cylinder with broken neck. There is no second seal. There isn't a groove for one either. I'll fiddle around some more hopefully on the weekend. Maybe I'm not pressing the elbow into the master forcefully enough....

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Discussion Starter · #12 ·
I think I've done it. I pulled the pipe of both brackets at the fire wall to allow the elbow more movement.

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I was then able to easily push the elbow into the master cylinder. And yes, it gave a rewarding click. Pushed circlip in, and no movement. Pressing the clutch pedal down, doesn't make it leak and what's more, pedal returns to up position by itself. After work I will bleed the system. Then need to reinstall coolant reservoir, top up fluids and reinstall everything else above the gearbox.

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It's been a while since I looked inside one tbh, so I might be wrong about the internal seal. Swear there was one though, but I'm getting old so probably wrong.

So it just wasn't home all the way?
 

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Discussion Starter · #14 ·
Yes, suspect elbow hadn't gone in all the way.

1st round of bleeding went well. No leaks. Pedal not coming back up by itself, but I'll have a second go tomorrow.
 

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Discussion Starter · #15 ·
I bled the clutch today. All is well. Clutch pedal comes back up. No leak. Brake pedal as normal. But my saga continues....
 
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