# Can low Brake Fluid cause a clutch failure?



## spydox (Apr 4, 2013)

Sunday, at a light, I couldn't shift into first and the clutch pedal went to the floor with no resistance. I pushed the car off the road, and had it towed to a shop. 

This morning I went to the shop. He pushed the pedal and it had pressure 1/2 way down. He pumped it 2-3 times and it was fine again.

He said it sounded like loss of hydrahlic pressure- and checked fluids. The brake fluild was perhaps 3/4in low. He topped it off up the the MAX line, and said drive it- see how it does. 

Of course now I'm spooked that it might fail again. Does this sound right- that brake fluid could cause clutch failure? How much confidence should I have in this diagnosis?


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## DerBassSpieler (May 12, 2008)

The clutch uses the brake fluid for its hydraulics. Find the leak and fix it before you give yourself bigger brake and clutch problems


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## l88m22vette (Mar 2, 2006)

It wouldn't cause a failure, it would just not work because of the lack of fluid pressure.


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## spydox (Apr 4, 2013)

*I guess its NOT the fluid level*

The mechanic topped it off, I drove like 5 miles, and at the next long top light, same thing.... Only the last 1/4 of pedal had any resistance. Luckily I was able to get it into 1st and limp home. Commuting on the mountainbike again- gonna check fluids when I get home (it was dark when I got home and dark when I left)...

Thanks for the tips guys- a month ago it was problem free, now I have speed sensor implausible reading, secondardary air leak, and this clutch problem. I just reached that point when I'm asking myself WHY DIDN'T I TRADE IT A MONTH AGO????

Oh well I need to bicycle anyhow, beer are taking their toll

...


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## darrenbyrnes (Jan 4, 2005)

It may be the slave cylinder. Mine needed to be replaced and, depending on the model you have, it can be a PITA to get at.


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## D2O (May 12, 2012)

Definitely sounds like it could be the slave. If it is the 6-spd the slave is integrated into the throw-out bearing, meaning that the transmission has to come off to replace it. When mine went it first started slipping the clutch since the leak cause break fluid to coat the pressure plate and clutch disc.


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## spydox (Apr 4, 2013)

*Slave cyl*

Thanks guys- I have the AMU. The mechanic said the slave is inside the bell housing? He said its a very expensive job. He wants me to bring it in (another tow- I'll need to wait a bit wife is already torqued!~) to see if he sees fluid leaking.

Oddly though, the break cyl resivoir seems to be topped off still, and no drips under the car. I dont see any leaks.

I check on EBAY it looks like I can get a clutch MASTER Cylinder for about $30. Wouldn't that be a possible source of loss of pedal resistance too?


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## spydox (Apr 4, 2013)

D2O said:


> Definitely sounds like it could be the slave. If it is the 6-spd the slave is integrated into the throw-out bearing, meaning that the transmission has to come off to replace it. When mine went it first started slipping the clutch since the leak cause break fluid to coat the pressure plate and clutch disc.


I do have the 6 speed. I'm not sensing any clutch slipping at all. The only symptom really is the loss of pedal back pressure (and consequential loss of ability to clutch!)...


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## darrenbyrnes (Jan 4, 2005)

I have a 5 speed but it's a Quattro...so my slave is in the bell housing...

:thumbdown::thumbdown::thumbdown:


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## rstolz (Jun 16, 2009)

blown internal seals of the clutch master or slave. That doesn't always show up as a visible leak.


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## spydox (Apr 4, 2013)

*master or slave?*



rstolz said:


> blown internal seals of the clutch master or slave. That doesn't always show up as a visible leak.


Is there a simple way to diagnose if it's master or slave ? I've already read of cases where owners replaced the master and saw no improvement. Whichever I need to do, I'd rather do just the one that failed. Right now the car is parked. DOA.


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## darrenbyrnes (Jan 4, 2005)

Well, the master is a lot easier to get at and isn't all THAT expensive. You could do that first, then if no improvement, do the slave...

:beer::beer::beer:


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## l88m22vette (Mar 2, 2006)

Swapping a master or slave is actually pretty easy its just time-consuming since you have to take out the airbox and other engine stuff, along with removing the lower dash and pedal assemblies, but its all done with simple tools :thumbup:


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## thzpcs (Apr 19, 2014)

Since it was low, could there possibly be air in the system that needs to be bled?


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## rstolz (Jun 16, 2009)

yes, but you need to deal with why it got low to begin with. It's a sealed system, fluid doesn't just disappear; and if it's blown seals, adding more fluid won't fix anything.


As far as diagnosing, you already did. you verified that one of the cylinders was bad by doing the pedal pump test. if it's bad seals, generally if you pump the pedal you can get enough force built up for it to feel fine, though ultimately you allowing more fluid to slowly seep around the seals.

There's no real good way to to identify which of the 2 cylinders is bad, but it's better to assume the master first, as it is MUCH easier to deal with on an 02M. With 02J trasn's, the slave is easier.

The master is pretty easy to swap out. just need to free it from the pedal. installing the new one will be harder, as you will need to bench bleed it, and not allow any fluid to leak out as you install it.


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## spydox (Apr 4, 2013)

rstolz said:


> yes, but you need to deal with why it got low to begin with. It's a sealed system, fluid doesn't just disappear; and if it's blown seals, adding more fluid won't fix anything.
> 
> 
> As far as diagnosing, you already did. you verified that one of the cylinders was bad by doing the pedal pump test. if it's bad seals, generally if you pump the pedal you can get enough force built up for it to feel fine, though ultimately you allowing more fluid to slowly seep around the seals.
> ...


Thanks guys, I think based on what I'm reading that I'll let my mechanic do this one. Trying to get this changed out in 100 degree August temps would about kill me..

I guess its possible air got into the system, but the level wasn't THAT low. Perhaps 1-2cm tops. But I'll ask the mechanic to try to bleed it first..


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## spydox (Apr 4, 2013)

*slave?*



l88m22vette said:


> Swapping a master or slave is actually pretty easy its just time-consuming since you have to take out the airbox and other engine stuff, along with removing the lower dash and pedal assemblies, but its all done with simple tools :thumbup:


I thought I read that replacing the slave meant removing the transmission?


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## lite1979 (Sep 9, 2005)

You are correct. Replacing the clutch slave cylinder on an O2M transmission means removing the transmission.


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## spydox (Apr 4, 2013)

*Got ECS OEM CLUTCH MASTER*

Go it at the shop - I had told the mechanic that my pals in the forum said no special tools were needed to replace the master. Well he called me in and showed me a printout of a tool it says was required- looked sort of like a clothespin? He said next week he'll look in more detail once the brake master vacuum housing is out...

HUH?


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## l88m22vette (Mar 2, 2006)

lite1979 said:


> You are correct. Replacing the clutch slave cylinder on an O2M transmission means removing the transmission.


No, you need to remove it for the throwout bearing, but the clutch slave is to the lower right of the master cylinder (my Tilton slave with its secondary reservoir):


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## spydox (Apr 4, 2013)

*master special tools*



l88m22vette said:


> No, you need to remove it for the throwout bearing, but the clutch slave is to the lower right of the master cylinder (my Tilton slave with its secondary reservoir):


Throwout? Thanks but I'm trying to get the MASTER replaced. Earlier Mr 88m wrote:

"88m22vette

Swapping a master or slave is actually pretty easy its just time-consuming since you have to take out the airbox and other engine stuff, along with removing the lower dash and pedal assemblies, but its all done with simple tools"

but the mechanic found a technote that said needed to buy a specific Audi tool (he wasnt sure if it specified 2 different tools)?


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## lite1979 (Sep 9, 2005)

I don't know why you contradicted me there, but if it's an O2M, then the clutch slave cylinder is inside the bell housing, and won't come out without removing the transmission.

Back to the OP's work, though, replacing the clutch _master_ cylinder should be much less time-consuming, and does reside to the lower-right of the brake master cylinder.


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## DTMVDUB (Jun 5, 2003)

*clutch*

The tool your mechanic is referring to is the Clutch Alignment Tool. 
http://www.germanautoparts.com/Tools/Volkswagen/Clutch+&+transmission+tools

If your mechanic isn't familiar with this simple tool, it would be best to have it diagnosed by an experienced VW mechanic.

2 years ago my clutch pedal dropped to the floor. The clutch slaver cylinder died and leaked brake fluid onto everything. It all had to be replaced.

Now, I'm experiencing the same problem as you. I have a loss of brake fluid and sometimes the clutch won't engage. There's brake fluid dripping from the bell housing area. I'm not taking any chances on the clutch, flywheel, or pressure plate being damaged so it's all getting replaced again.


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## spydox (Apr 4, 2013)

*worst possible result*

Well $500 later for P&L, the new master did exactly nothing to improve the clutch issues. Now its slave and clutch replacement time.

ECS parts the best option?

Anyone want a TT cheep?


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## D2O (May 12, 2012)

That sucks. I got mine from CTS turbo IIRC. Part is cheap.... Relative to the cost of having a mechanic drop you transmission.


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## lite1979 (Sep 9, 2005)

If I lived nearby, I'd help you drop the tranny myself. It's definitely harder than a FWD car, but worth the effort because of the money you save, imho.


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## spydox (Apr 4, 2013)

*thanks for the offer*



lite1979 said:


> If I lived nearby, I'd help you drop the tranny myself. It's definitely harder than a FWD car, but worth the effort because of the money you save, imho.


Thanks for the offer, but 1/2 the tranny shop floor is neatly arranged parts off the TT to get this thing out. WAY beyond my expertise. I woulda misplaced enough parts to pay for the labor (especially when you consider an average Audi bolt is probably $25). 










He said from underneath it appears the turbo is also leaking as well as many hoses. 

The plan is getting her buttoned up, pay the man, lick my wounds, and go find a 6sp Shelby GT before the next major thing goes.

Then again, that's what I told myself after the LAST major repair, and after I drove it and re-fell in love with the car, I said ONE MORE CHANCE.. I'll probably do the same thing this time... That's what lovesick fools like me do...

:banghead:


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