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LR5V

Gti - new Clutch - Not disengaging - It wasn't the Master or slave cylinder!

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OK - as title new clutch kit, suspect something in the hydraulics was on the way out before I parked the Lupo.

New pressure plate must be a good bit stronger and finished the worn hydraulic part off.

First bleed I initially used a one-man with a one way valve, seemed to work OK.

Second bleed : after Discovering the problem, manually bled - no fluid coming out, pedal returning.

Third bleed: vacuum pump, fluid coming out, but pedal staying down. 

So - what has broken? I get the feeling its master cylinder??

 

Edited by LR5V

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I’d try back bleeding it first, used to be a right nightmare on the minis to bleed up but back bleeding always (eventually) sorted it out.

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You think air in the system?

Forgot to mention that when I did the clutch I didn't disconnect the slave from its hose - removed form gearbox and tucked it to one side - only reason I bled it was to the old brake fluid was grotty, as usual clutch was even worse.

Edited by LR5V

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Pedal up, pedal down.

Play with spanner.

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No change  - I have put a third of a litre of brake fluid through it ...and just to add to the joy, the nipple is starting to round off

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Get one of those pressure bleed kits. Or stick a schrader valve in a spare reservoir cap :)

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I have one man pressure kit - don't like it. if you reduce the tyre pressure it does not do too much and keeps needing blown up. If you dont reduce the tyre pressure it puts too much pressure on the system.

I have a hand vacuum pump kit & also a vacuum kit for the compressor -but the compressor is out of action just now. The vacuum only sucks fluid out when the pedal is down, but it only takes the same amount each time

I'm still convinced there is a faulty hydraulic item, when I took the box and clutch off there was a lot of dust - close to packed with clutch dust - could well be something weak

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Fitting a slave isn't that hard but it sounds like air.

Is there any clutch fluid building up now?

 

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If the old fluid was dark with black specs then that's seals going, but it does sound like air. 

Did a Mondeo a while back, ended up with my big fluid drainer on the nipple sucking hard while i pumped the pedal a few times, manual bleeding, using a bleeding kit didn't work.

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There is no change in the pedal feel. as mentioned in build thread it is a lot lighter than it was before  - no difference in feel selecting gear clutch up or down. Nothing is moving.

@Sausage Yes The old fluid was full of crud, some of it looked black. cant remember if it was the first flushed fluid - suggesting slave - or later being master cylinder. Was that back flushing you described - as suggested by Pete?

Run out of light and I am away tomorrow

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1 hour ago, LR5V said:

There is no change in the pedal feel. as mentioned in build thread it is a lot lighter than it was before  - no difference in feel selecting gear clutch up or down. Nothing is moving.

@Sausage Yes The old fluid was full of crud, some of it looked black. cant remember if it was the first flushed fluid - suggesting slave - or later being master cylinder. Was that back flushing you described - as suggested by Pete?

Run out of light and I am away tomorrow

No normal way on the slave nipple. (no not that sort of slave or nipple).

Pull slave out, restrain the rod somehow and apply pedal pressure, see what it is doing. Might be a non hydraulic issue.

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I thought about off car bleeding, decent zip tie might do it in the bolt holes 

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56 minutes ago, Sausage said:

No normal way on the slave nipple. (no not that sort of slave or nipple).

Pull slave out, restrain the rod somehow and apply pedal pressure, see what it is doing. Might be a non hydraulic issue.

 

49 minutes ago, Rich said:

I thought about off car bleeding, decent zip tie might do it in the bolt holes 

Is that to test the slave? - slave limiter: Fizzy drinks bottle - neck cut off, lid on, cable tie around collar and 2 other ties looped through first tie & bolt holes

I will try backfilling first, using vacuum on disconnected feed pipe & some form of hopper on the slave nipple

still think its master cylinder

-Sadly this will all have to wait till next weekend

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Master cylinder has nothing to do with clutch and the clutch master seems very reliable.

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Looks to me like he’s back bleeding it.

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21 minutes ago, Pete said:

Looks to me like he’s back bleeding it.

He is. Quite clever with the oil can actually, wish I'd thought of this.👍

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I thought that’s how everyone did it?

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You can just pressure bleed it through?! I thought that's the usual method.... especially with ABS pumps when doing brakes.

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Well my clutch nightmare continues.

Ordered one of these. after vacuuming out brake fluid from the reservoir, I back bled the system. Constantly watching the reservoir, I was pleased when a few bubbles of air came out - I thought great the guys were correct.

Sadly the relief was short lived as there was no change, so dived inside and ordered a click and collect from Euro's for a Sachs slave with weekend 37%. Drove 2 thirds of the way to find I had left my wallet at home! wallet collected, part purchased, fitted - so much easier with the hose disconnected - clutch line bled again. Jumped into the Lupo, there was now some resistance, but it still seemed light. Engine off, clutch down gear changes felt a little better, but there was now change with engine on.

For the slave swap, I had drained the line and reservoir into a shallow dish on inspection I could see a 1mm fleck of rubber - suggesting a seal had failed. Old slave does not show any obvious failure and thinking about the clutch install, I believe its pretty much impossible to screw up fitment:

The pressure plate wont fit over the clutch plate if it's the wrong way round, pressure plate can only be mounted in one position on the flywheel, the release bearing can only clip into the lever one way, the tube that locates the release bearing can only bolt onto the bell housing one way and lastly the lever can only clip in one way - with slave off I checked the lever, it seems to be in the same location, clipped into the bell-housing

Do you good folk agree that its got to be the master cylinder?

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i hope for your sake that it is.

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Have you removed the slave and restrained the rod, pedal should have obvious resistance then? 

 

 

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No fella - out of frustration I opted for the expensive option of swapping components over. 

As covered above, I do not think its possible (even for me) to screw up the clutch install.  The only thing left is the master cylinder - Clutch master cylinder for pedant Rich!

I had not cleaned out the dish I used to empty out the clutch line into, this is the black rubber debris and other stuff - the bigger black lump is bigger than I said before, closer to 2mm square:

oOPI74.jpg

New Sachs master cylinder ordered - ebay seller is one of those ones demanding registration number before posting... despite at check out adding the info in "message to seller" they still wrote back asking for info... hopefully there wont be any further delay and turn up Tuesday or Wednesday

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Luck not currently improving - parcel delivered today - Instead of the expected master cylinder I ordered, I got a nice boxed set of Boge bump stops!

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