Clutch pedal, has anyone got to the bottom of problem

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Gavinrs4
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Clutch pedal, has anyone got to the bottom of problem

Post by Gavinrs4 » Fri May 09, 2014 10:47 pm

I know this question has been asked before but when I read through the answers I cannot get to the bottom of it as there has been different solutions. I only have to show it to the redline once and the clutch pedal goes to the floor then raises about an inch or so until it cools and returns up. The clutch doesn't slip or feel on its way out. Thanks and please go easy on me as this is my first forum post. Thanks
And also is there any groups in manchester area that meet up?

Wavey Dynamicist
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Re: Clutch pedal, has anyone got to the bottom of problem

Post by Wavey Dynamicist » Sat May 10, 2014 12:12 am

Same problem here.. No word on a 100% fix other than full clutch assembly replacement..

Very strange problem everything i expect that would fix it has been proven to be hit and miss.. I'm tending to think it's due to manufacturing tolerances, so many variables that sometimes fix and sometimes don't..
2007 RS4 Saloon; Mugello Blue

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vestax32
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Re: Clutch pedal, has anyone got to the bottom of problem

Post by vestax32 » Sat May 10, 2014 5:10 am

New clutch, simple.
Current;
18 Daytona Grey RS4
16 Green R8

Past;
17 Misano RS6 PE
66 Sapphire BMW F80 M3.
16 Floret Silver RS6 Performance
18 Mythos Black RS4
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13 Daytona Gey RS6 (Don't ask!)
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TonyHayers
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Re: Clutch pedal, has anyone got to the bottom of problem

Post by TonyHayers » Sat May 10, 2014 8:43 am

vestax32 wrote:New clutch, simple.
Not true. I had brand new clutch and pressure plate. 2 weeks later first occurrence of sticky clutch.
06 Phantom Black Saloon:
DONE: Water Meth Injection, Carbon clean at 64k, CAI, Gutted Precats, Non-res x-pipe, H&R 8mm spacers, H&R springs
^ GONE :cry:

jaysrs4
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Re: Clutch pedal, has anyone got to the bottom of problem

Post by jaysrs4 » Sat May 10, 2014 8:47 am

TonyHayers wrote:
vestax32 wrote:New clutch, simple.
Not true. I had brand new clutch and pressure plate. 2 weeks later first occurrence of sticky clutch.
Ok so what if you go into a dealer and ask them to cure the problem. If they replace bits that don't cure it, what's the story with paying them for work carried out unnecessarily?
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TonyHayers
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Re: Clutch pedal, has anyone got to the bottom of problem

Post by TonyHayers » Sat May 10, 2014 10:41 am

Jay I'm not sure if anyone would guarantee to cure a problem specifically, they'd probably limit any guarantee to their workmanship and the parts fitted.
06 Phantom Black Saloon:
DONE: Water Meth Injection, Carbon clean at 64k, CAI, Gutted Precats, Non-res x-pipe, H&R 8mm spacers, H&R springs
^ GONE :cry:

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TonyHayers
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Re: Clutch pedal, has anyone got to the bottom of problem

Post by TonyHayers » Sat May 10, 2014 10:45 am

I'm planning on replacing all the clutch hydraulics inc pipes and sleeves etc. My feeling is that there are possibly a number of subtly different symptoms and factors involved - this would explain why two owners with *seemingly* the same problem can implement the same fixes and achieve varying results.
06 Phantom Black Saloon:
DONE: Water Meth Injection, Carbon clean at 64k, CAI, Gutted Precats, Non-res x-pipe, H&R 8mm spacers, H&R springs
^ GONE :cry:

irishmike
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Re: Clutch pedal, has anyone got to the bottom of problem

Post by irishmike » Sat May 10, 2014 11:13 am

On mine I had a full fulid flush and replace. That didn't work.
They then replaced all the hydraulics. Pipes, master and slave cylinder.

Not been an issue since. :)

jaysrs4
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Re: Clutch pedal, has anyone got to the bottom of problem

Post by jaysrs4 » Sat May 10, 2014 11:16 am

It has to be heat or vacuum related. There's no other reason - most people report this issue after 'spirited' driving.

However I don't think it even takes a good caining, only a couple whips round to 8.5k and the pedal begins to get a bit sticky.
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Gavinrs4
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Re: Clutch pedal, has anyone got to the bottom of problem

Post by Gavinrs4 » Sat May 10, 2014 2:24 pm

Thanks guys, it is a strange one for sure. A couple of my friends who are mechanics feel as if it's something to do with the hydraulics. It's a shame as not had the car long and want to get it sorted, I don't mind buying a new clutch kit and flywheel etc. just want it right.
Apart from that, the car is ace and much better than I though it was going to be.

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PetrolDave
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Re: Clutch pedal, has anyone got to the bottom of problem

Post by PetrolDave » Sat May 10, 2014 3:00 pm

We've been going round this loop several times on here over the nearly 8 years I've had my RS4, and the conclusion thus far is.... nobody knows (as they say on QI).

Not every owner suffers from the problem.
Things that cure it for some, have no effect for others.

I've had it happen a couple of times - both after doing a high rev launch and I had to hook my foot under the clutch pedal and pull it up to fully engage the clutch - which to me sounds like either the clutch is being held partially disengaged by fluid not returning (Audi's suggested mechanism) and/or the clutch plates sticking together and/or the return spring not being strong enough (the clutch pedal on the RS4 is much lighter than on a Renault 5 GT Turbo I owned many years ago...).
Gone: 2006 B7 RS4 Avant (Phantom Black)

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ArthurPE
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Re: Clutch pedal, has anyone got to the bottom of problem

Post by ArthurPE » Sat May 10, 2014 4:05 pm

imo it's the friction of the throw out bearing on the guide bushing
the tolerance shrinks when hot and it binds (dust and debris may contribute)
clearancing and polishing may help
the type of return mechanism is a 2 stage (to make the clutch easier to operate)
but on the return a spring has to pull it through a 'knuckle' or point of higher resistance before the resistance gets lower
this is the point it gets stuck, a slight pull gets it over this point
a stronger spring may help
some vette guys have eliminated a spring and they say it fixes it (although the clutch gets a bit stiffer)

you can reproduce it pretty consistently
car warmed up and stationary
rev engine up and down a few times with clutch depressed
release and depress, should stick
Last edited by ArthurPE on Sat May 10, 2014 4:11 pm, edited 3 times in total.
Two things are infinite: the universe and human stupidity; and I'm not sure about the the universe...Albert Einstein

wrekka
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Re: Clutch pedal, has anyone got to the bottom of problem

Post by wrekka » Sat May 10, 2014 4:06 pm

Do people still have this problem who have fitted sachs or loba clutches?
Sold: 2012 RS3 APR St2 exclusive buckets!
Sold: 2014 Audi S4 Avant Black Edition (too slow as a stock car-doesn't sound good);
2016 RS6 performance with Non-res milltek (gutted to sell it) ;
2014 C7, Misano c6 mrc stage 2. AAS Custom Exhaust, cat bypass, itg filters. 731ps 1058nm. Superrbike quick!
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PetrolDave
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Re: Clutch pedal, has anyone got to the bottom of problem

Post by PetrolDave » Sat May 10, 2014 5:00 pm

ArthurPE wrote:imo it's the friction of the throw out bearing on the guide bushing
the tolerance shrinks when hot and it binds (dust and debris may contribute)
I remember someone having the guide bushing checked and finding this - was that you Arthur?
Gone: 2006 B7 RS4 Avant (Phantom Black)

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Gavla
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Re: Clutch pedal, has anyone got to the bottom of problem

Post by Gavla » Sat May 10, 2014 6:15 pm

wrekka wrote:Do people still have this problem who have fitted sachs or loba clutches?
I decided to go for an upgrade to a LOBA 55ONM Stage 1 and I've had no similar issues yet....but then I have only done 3K on it. :bigblink:

The only thing you notice with this clutch is sometimes there is chatter at low revs but you get used to it and can easily drive round it...
RS4 (B7) Saloon Phantom Black, Black Optics, Tech Pack, KW Lowering Spring Kit, Stern Adjustable Arms, MRC Stage 2, Stage 1 Manifold, CAF, LOBA Stage 1 Clutch,
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