[V8] Audi Funk - Clutch Hydraulics

Sun Jun 16 16:14:18 PDT 2013

I went through all of this about a year ago. Definitely not fun. After the 40th or so try though I was able to do the whole job from the top. Once you know where the parts are you can sort of feel them. 
To get mine in that last little bit I think I used some sort of shim on that stop thing at the back of the cylinder.

Dave

Sent from my iPhone

On Jun 16, 2013, at 12:16 PM, Professor GT gmail <CavalloGT at gmail.com> wrote:

> The conclusion to a failed clutch actuation hydraulic system.
> 
> Hope others can benefit from the experience.
> 
> I spent quite a while yesterday fixing it. I had fluid literally pouring out of the bellhousing, so I set out to replace the slave. What a nightmare! Had to go in from underneath after removing the L/S axle. The slave is designed at the piston end to fit into a tapered seat in the bellhousing, and then at the feed/hydraulic line end a boss with a single cap screw anchors it. The mating boss on the bellhousing that receives the bolt has a raised finger (for lack of a better term) that holds the cylinder in place after it is pushed into position, compressing the return spring.
> 
> Well, the job was extremely annoying, and IMHO impossible without the use of a vehicle lift. I could not see a reasonable chance of attacking it from the top as it sits under the steering rack, hence a bottom end job. 
> 
> The cylinder is barely visible from underneath as well. Following the hydraulic line to it will get you there. Removing the L/S axle is the only way I could gain any access, and the axle comes out with a minimal amount of fuss other than getting the inner CV boot heat shield out of the way. (The three 6mm Allen's that hold it in are a pain to access as the exhaust and subframe are in the way).
> 
> Anyway, to confirm the diagnosis I refilled the brake master reservoir, which feeds the clutch system, and upon having my able-bodied assistant pump the pedal (it had only a couple inches of travel left, right on the floor) it began pouring fluid out of the bell housing!
> 
> So, obviously the slave piston/seal was kaput!
> 
> Now, let the games begin! After you snake your arm between the exhaust and the subframe, with the sharp subframe weld seam digging into your forearm (my forearm is terribly irritated, sore and swollen as a result) all you need to do is remove the retaining cap screw and release the slave. Just pry it up from the bottom and it should rotate up and out. You may have to pursuance it a bit with special tool SST-001BFH, if you know what I mean!
> 
> Once it was out and hanging by the line use a line wrench to remove it from the line. Screw the new one into the line, tighten it and then crack the bleeder open.
> 
> Now the "fun" part, and I use that term very loosely, as I could think of myriad other things I'd rather be doing than having that subframe chewing away on my arm!
> 
> Place the new slave into its cavity, shoving it forward to compress the return spring just far enough for the mounting boss of the slave to pop down into the cavity in front of the raised tab or "finger" as I called it earlier. Now this is the rub: no matter what I did, I could not get that bugger to drop down into place I'm front of that dam tab. I even custom ground a tapered punch of sorts in an attempt to use the mounting hole as a pry point to lever the slave forward into place - NOT!
> 
> Nothing seemed to be able to give me that tiny bit I needed (about 1/16" - sorry, this is America and we don't need no stinkin' Metrics system! LOL!).
> 
> So, I pulled the slave back down and went into the, "is this the right part?"mode. Well, the cylinder seemed to be a perfect match, but the pushrods was a scosch longer! Yes, 'bout 1/16"!
> 
> So, I took a gander and attempted to fit the slave I'm place without the pushrods in place. Sounds like a plan, and then if it fits I'll use the original pushrods!
> 
> NOT!
> 
> &@$?%£}! Still didn't fit! So, it's not the pushrod length. 
> 
> This is now going on about 6 hours of screwing with this POS! Or should I say 6 hours of this POS screwing with me!
> 
> So now I'm about ready to use Special Service Tool SST-002-COG&M (Can of Gas & Match)!
> 
> I'm staring blindly at this little piece of metal (slave cyl) that is just kickin my ass, and something (let's call it divine intervention) tells me, "You know, the fit-up of the tapered seat into the bellhousing may be hampered by the extremely thick coating of paint that was applied to this part. Why don't you try sanding that surface clean?"
> 
> Well, I tried just about everything else I know to do, and my trusty compadre who's owned his own transmission shop for over 30 years is at this point totally stumped as well, so hey, I got nothin else too lose.
> 
> So, I sand the bitch clean at the tapered mounting end, and what do you know, the little sucker falls right into place! Who woulda thunk it? I was so relieved, I almost peed myself!
> 
> The other bonus is that the outer CV boot was torn, so while I was there I swapped one from a spare axle as a temporary fix until I get some new boots and service all of them.
> 
> The pedal bled out with no fuss, and honestly it's never had such a good pedal. I used the slightly longer pushrod that came with the new slave and the pedal is higher than it's ever been since I've owned the car (got it in '07).
> 
> As an aside, i think i'm going to take a spare sub-frame and do a bit of custom modification to it, relieving it of those nasty sharp edges and boxing it off. This would certainly make life easier in the future, and .............
> 
> Well, anyway my V8 is once again "Off the Hook", and hopefully will remain that way for many more happy motoring miles.
> 
> Owdee on!
> 
> 
> 
> Thanks,
> 
> ProfessorGT
> (Sent from my iPhone4)
> 
> On Jun 15, 2013, at 10:05 PM, Steve B <urq at pacbell.net> wrote:
> 
>> Many times on the V8s and other quattros I've been able to lift the clutch pedal using my toe and usually it will work again.
>> 
>> If the slave fails you should be able to see that you're losing brake fluid, are you sure it needs to be replaced?  IME the master is more likely the culprit, and much easier to R&R.  If it is the original M/C you may need to hack a 6mm Allen key make a tool to loosen one of the bolts. 
>> 
>> If you haven't bled the clutch I'd recommend doing that first.  If the fluid in the reservoir on the brake M/C gets low, the line to the clutch M/C may be "dry" and you may get air in the system.
>> 
>> Steve Buchholz
>> 
>> 
>> Professor GT gmail <CavalloGT at gmail.com> wrote:
>> 
>> Wow! Towed twice in 7 days!
>> 
>> Think I'll airbrush on the back of my trunk lid a tow truck towing the Audi logo with the caption, "Runs Great When It's "Off the Hook!""
>> 
>> And about that automatic versus stick debate:
>> 
>> Score one more for automatics, because even though the "mystery" of automatics makes some folks afraid of "all the extra hydraulic complexities", the clutch pedal on my stick fell to the floor and left me mid span on the Tappan Zee Bridge last night in bumper-to-bumper traffic. This meant having to stop and start the car with the starter to make it off the bridge and get to a safe point to be towed. 
>> I was sure wishing that I built the automatic car instead! (NO Ron, my stick is NOT for sale. If I was ready to sell, it would be too expensive anyway, even though there would most likely be no takers.) The stick car is a fun ride, but the automatic version is way more practical, and performs way better!
>> 
>> Now, I'm about to find out if the slave cyl can be replaced w/o removing the Trans! 
>> Wish me luck!
>> 
>> Thanks,
>> 
>> ProfessorGT
>> (Sent from my iPhone4)
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> 
> Thanks,
> 
> ProfessorGT
> (Sent from my iPhone4)
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