Distance from Slave Entry hole to Clutch Fork needed

[cu52]

Working on the Allroad I purchased to replace the S4. Hoping someone over hear in B5-S4 forum might have the answer for me.

Anyone know the acceptable range of the distance from the outside of the slave cylinder to the point the slave would touch the clutch fork? Asking as I am pretty confident I have my slave installed and bleed correctly, however the first 1/2 of the pedal is good, then it is HARD. 1st slave blew up, I thought I had it installed wrong, thinking now that the distance is too far and the slave is over extending. Distance is approx 3" from outside of the slave hole, to the clutch fork. Vehicle has 111K miles. I bought it with the clutch stuck to the floor and what appeared to be a broken slave.....

I was hoping to get the car running to see what else it may need before pulling the engine/trans for repairs, but I may have clutch or PP issues it sounds like? If anyone knows that acceptable distance range it would be very helpful.

Or if anyone in the Denver metro area is willing to help check her out that would be even better! I can pay in BEER!

Thanks for the help!

[Cgoon009]

Working on the Allroad I purchased to replace the S4. Hoping someone over hear in B5-S4 forum might have the answer for me.

Anyone know the acceptable range of the distance from the outside of the slave cylinder to the point the slave would touch the clutch fork? Asking as I am pretty confident I have my slave installed and bleed correctly, however the first 1/2 of the pedal is good, then it is HARD. 1st slave blew up, I thought I had it installed wrong, thinking now that the distance is too far and the slave is over extending. Distance is approx 3" from outside of the slave hole, to the clutch fork. Vehicle has 111K miles. I bought it with the clutch stuck to the floor and what appeared to be a broken slave.....

I was hoping to get the car running to see what else it may need before pulling the engine/trans for repairs, but I may have clutch or PP issues it sounds like? If anyone knows that acceptable distance range it would be very helpful.

Or if anyone in the Denver metro area is willing to help check her out that would be even better! I can pay in BEER!

Thanks for the help!

While a bent clutch fork is possible, its very unlikely. What you felt above is due to the slave cylinder not being lined up correctly. If your pedal feels this way, take it out and try again. 9 times out of 10, the slave isn't lined up with the fork. You will know when it is, because you will feel the slave cylinder compressing almost as soon as its put in. Anything else and you missed it. If you are doing this on the car, then the best advice I can give you is to try coming in with the SC lined up parallel with the transmission and at a slight downwards angle, to miss the shifter linkage. The goal is to get as close to dead on as you can, so try using the play in the rod to your advantage. Good luck, it can be done, with alot of cursing and yelling.

[christianb5s4]

^What he said. I had a hell of a time getting the slave cylinder piston seated correctly in the clutch fork with the engine and trans in the car but it did go in eventually. The last thing you want to have happen is let the slave cylinder piston fall into the transmission housing, the stock slaves are easier to compress than the metal ones.

[cu52]

Did the above about 10 times last night trying different angles and approaches. I could tell when it was wrong. I also experienced exactly what you describe on the compression immediately multiple times, but it did not compress as far as I remember when I re-installed the engine/trans on the S4 in January (1st try). That is why I was thinking there could be other issues if the distance from the fork to the entry point on the slave hole is longer than it should be.

Also thanks for responses and help thus far!

[ReggieNoble]

Did you check the rod length on the old sc vs the new sc? I remember seeing some diff sizes

[Cgoon009]

Did the above about 10 times last night trying different angles and approaches. I could tell when it was wrong. I also experienced exactly what you describe on the compression immediately multiple times, but it did not compress as far as I remember when I re-installed the engine/trans on the S4 in January (1st try). That is why I was thinking there could be other issues if the distance from the fork to the entry point on the slave hole is longer than it should be.

Also thanks for responses and help thus far!

Are you using a metal version? Is the part new?

Also it can be frustrating because it will feel like its compressing but what you are feeling is the rubber boot resisting and catching on the opening into the bell housing. I lot of guys will coat the boot with a bit of grease to help it slide in.

You will be able to tell when you have caught it, as it will take alot of force to push it forward when the rod is in the dimple of the fork. The change in resistance was noticeable very quickly.

If you are still concerned that it may be a bent fork, stick your finger in the opening and locate the dimple on the fork. you should be able to get your entire finger in the opening before you feel the fork. My fingers are about 3-3.5" in length for reference. You can also use a better method to find out just how far the dimple is. Again, based on the symptoms you described it sounds like it just has not lined up yet.





That is what you are trying to hit

[cu52]

First I installed a new Sachs OEM unit. Had the same issue, pressed the hard pedal like an idiot and BOOM blew it out. Currently a Carquest Metal slave, new. RE-assembled the Sachs and compared total length between that and the carquest and they are the same using digital calipers. When installing the slave I verified I was not getting resistance and was in fact compressing the slave by watching the fluid reservoir fill back up with brake fluid.

To determine the ~3" distance from the entry of the hole to the dimple on the fork I used the OEM pin and found the dimple and could see the pin just barely sticking out of the hole. I cannot get my fingers to feel the fork from above or from below, my hands will not bend that way. What is odd is that the dimple does not seem centered in the hole. Feels like it is center height, but significantly toward the drivers side.

[b7_Andy]

Weird this is exactly what happened on my B7 after doing my drivetrain swap. My clutch pedal felt correct part of the way down and then got really hard. The slave was maxing out before it could fully disengage the clutch. I reused my pressure plate and after looking at pictures I took, it seems that the teeth on my pressure plate are warped inward causing all the clutch components to move closer to the engine and making the slave reach further. If the slave missed the clutch fork the pedal would be rock hard from the beginning. I guarantee you're looking at the same problem I'm having. I'll be pulling my motor again on Saturday when I'm back in town. I live in Denver right near I-25 and Hampden. If you want to come over I'm going to measure the clutch fork distances with my current situation and then after I install the new clutch kit.

[Cgoon009]

Weird this is exactly what happened on my B7 after doing my drivetrain swap. My clutch pedal felt correct part of the way down and then got really hard. The slave was maxing out before it could fully disengage the clutch. I reused my pressure plate and after looking at pictures I took, it seems that the teeth on my pressure plate are warped inward causing all the clutch components to move closer to the engine and making the slave reach further. If the slave missed the clutch fork the pedal would be rock hard from the beginning. I guarantee you're looking at the same problem I'm having. I'll be pulling my motor again on Saturday when I'm back in town. I live in Denver right near I-25 and Hampden. If you want to come over I'm going to measure the clutch fork distances with my current situation and then after I install the new clutch kit.

This is not the case, the pedal will travel half way because when the system is bled, and the slave is in correctly it will be partly compressed. Bleeding the system while the slave is fully extended would make the pedal reach a "no travel" point higher up. But even so, the pedal will always have some play in it.

However its a good call to ask about the pp being adjusted correctly if it does have the sachs mechanism.

[b7_Andy]

This is not the case, the pedal will travel half way because when the system is bled, and the slave is in correctly it will be partly compressed. Bleeding the system while the slave is fully extended would make the pedal reach a "no travel" point higher up. But even so, the pedal will always have some play in it.

However its a good call to ask about the pp being adjusted correctly if it does have the sachs mechanism.

When I installed my slave a bunch of times trying to figure out if I had it in correct or not, the one time it was not on the clutch fork the pedal was rock hard from the very beginning, absolutely no travel. If there's no force against the end of the slave rod and the hydraulic system is bled, the rod will be pushed all the way and there will be zero pedal movement. Push the pedal at all and it will shoot the rod out.

[cu52]

Weird this is exactly what happened on my B7 after doing my drivetrain swap. My clutch pedal felt correct part of the way down and then got really hard. The slave was maxing out before it could fully disengage the clutch. I reused my pressure plate and after looking at pictures I took, it seems that the teeth on my pressure plate are warped inward causing all the clutch components to move closer to the engine and making the slave reach further. If the slave missed the clutch fork the pedal would be rock hard from the beginning. I guarantee you're looking at the same problem I'm having. I'll be pulling my motor again on Saturday when I'm back in town. I live in Denver right near I-25 and Hampden. If you want to come over I'm going to measure the clutch fork distances with my current situation and then after I install the new clutch kit.

I might be able to swing down depends on what we have going on with the kids this weekend, will PM you. Near I-25 and 144th.

When I installed my slave a bunch of times trying to figure out if I had it in correct or not, the one time it was not on the clutch fork the pedal was rock hard from the very beginning, absolutely no travel. If there's no force against the end of the slave rod and the hydraulic system is bled, the rod will be pushed all the way and there will be zero pedal movement. Push the pedal at all and it will shoot the rod out.

This was the same experience I had last night. If I missed it, the pedal had no travel distance, rock hard from the beginning. I assumed this was due to 1 of two things. Incorrectly and it was jammed between the case and the fork not allowing any extension, or it was fully extended. I am thinking 60% travel is because the slave is only 60% compressed rather than completely compressed decreasing the distance I can push the pedal in before the slave bottoms out. I could easily be wrong! Wish this was as easy to get to as the 2004 GTI I had!

[Cgoon009]

When I installed my slave a bunch of times trying to figure out if I had it in correct or not, the one time it was not on the clutch fork the pedal was rock hard from the very beginning, absolutely no travel. If there's no force against the end of the slave rod and the hydraulic system is bled, the rod will be pushed all the way and there will be zero pedal movement. Push the pedal at all and it will shoot the rod out.

So you bled the system with the rod installed incorrectly, and filled the entire system with fluid. Less pedal play makes sense then. However when installing a slave and missing the fork can also have exactly the symptoms described above. You get no pedal feed back till halfway and then it hits a wall.

He could have a pp that needs to be adjusted correctly. He also could just have missed the fork, or less likely bent or broke the fork.

[Cgoon009]

I might be able to swing down depends on what we have going on with the kids this weekend, will PM you. Near I-25 and 144th.



This was the same experience I had last night. If I missed it, the pedal had no travel distance, rock hard from the beginning. I assumed this was due to 1 of two things. Incorrectly and it was jammed between the case and the fork not allowing any extension, or it was fully extended. I am thinking 60% travel is because the slave is only 60% compressed rather than completely compressed decreasing the distance I can push the pedal in before the slave bottoms out. I could easily be wrong! Wish this was as easy to get to as the 2004 GTI I had!

I know what you mean, its an infuriating design. Especially on a C5 or B5 gen.

Here are somethings that may help. I found removing the axle gives me much more room to maneuver. Also if you have cats on your down pipes, it may be worth removing the driver side one to get more access. With the down pipe removed, the part can actually be seen and accessed from the top. If you decide to go that route, make sure you have a box wrench with a flex joint at the head. my bolts were 18mm, but yours could be different.

If you really think its something other then a missed fork, you will have to remove the transmission, so either way you will get it in the end.

[cu52]

Is it possible then that I have the slave in the right position and just need to re-bleed it? If the slave was bleed would it really matter if it was partially compressed or not compressed at all if all the air was removed from the system?

My understanding is that fluid can move to and from the slave when the clutch pedal is not in use, when the clutch pedal is down, the master changes it to a 1 way valve and only allows fluid to go toward the slave right?

[aysix]

At what angle are you putting the slave in? I've done this about 10 times and never had a problem. It puzzles me when i see threads like this. I install it from the top. I put the dick end in with the clutch line end facing up. I push it in and then twist the slave with the clutch line end facing to the drivers side. Perhaps if you're installing it at an odd angle from the bottom this might happen.

[b7_Andy]

Is it possible then that I have the slave in the right position and just need to re-bleed it? If the slave was bleed would it really matter if it was partially compressed or not compressed at all if all the air was removed from the system?

My understanding is that fluid can move to and from the slave when the clutch pedal is not in use, when the clutch pedal is down, the master changes it to a 1 way valve and only allows fluid to go toward the slave right?

I bled mine a bunch of different ways. I used a power bleeder, a two-person pedal-bleed. I bled the slave with the rear of the car way higher than the front and it still felt the same no matter what. I've done about 6 or so audi slave cylinders before so I knew something wasn't right with mine. Even if you don't get it bled correctly the system is self bleeding and will eventually feel normal after pumping it a few times. I did my buddy's slave cylinder road-side one time and we didn't have any tools to bleed it so we just pumped some fluid out after installing the new one and then started driving the car. It felt really spongy but after a few miles of driving it was back to normal. I spent days and days diagnosing my issue with my B7 and pretty much realized that the clutch fork spacing is off. If the pedal is going in part way and then getting hard, it's because the slave cylinder is maxing out before the clutch is fully disengaged. I'm 100% sure about that. Now what could be causing it is a mystery. I'm pretty sure mine is my pressure plate. It's very unlikely for an S4 clutch fork to bend... I've never heard of this happening to anyone. It's possible I guess, otherwise the plastic intermediate piece it rests on could have broke, which would cause the clutch fork to move further away and possibly be off center. When I tear mine back apart I'll be surprised if it's anything other than the pressure plate.

[cu52]

At what angle are you putting the slave in? I've done this about 10 times and never had a problem. It puzzles me when i see threads like this. I install it from the top. I put the dick end in with the clutch line end facing up. I push it in and then twist the slave with the clutch line end facing to the drivers side. Perhaps if you're installing it at an odd angle from the bottom this might happen.

That is exactly how I did it from the top. Start with the rod in have the bleed valve and connection pointing up, push in to get pressure, compress and watch fluid enter the reservoir and rotate 90 degrees to get it to sit on the mounting point.

[aysix]

That is exactly how I did it from the top. Start with the rod in have the bleed valve and connection pointing up, push in to get pressure, compress and watch fluid enter the reservoir and rotate 90 degrees to get it to sit on the mounting point.

Sounds right. Shit's fucked.

[b7_Andy]

So you bled the system with the rod installed incorrectly, and filled the entire system with fluid. Less pedal play makes sense then. However when installing a slave and missing the fork can also have exactly the symptoms described above. You get no pedal feed back till halfway and then it hits a wall.

He could have a pp that needs to be adjusted correctly. He also could just have missed the fork, or less likely bent or broke the fork.

My clutch hydraulic system was already bled 100%. With the line still connected to the slave, I tried reinstalling it several times. Every time it missed the clutch fork the pedal had absolutely no play and was rock-hard from the beginning. When I installed it the right way, I could feel the slave piston compressing as I pushed it in and then the pedal would feel normal until the last 2" of the throw and it would turn into a rock. This was because the slave had maxed out, but the clutch had not fully disengaged. I knew this because when the engine was running I could not shift into any gear. But if I put it in gear, clutched in, and then started the car, I could release the clutch and get the car to drive around. But if I went back into neutral, I couldn't get it back in gear. The clutch was so close to being fully disengaged that I could drive it if I started it in gear, but couldn't actually put it in gear with the motor running. I think I had a premature pressure plate failure and that was the cause of my synchros getting destroyed at only 60,000 miles. When I was driving my car around before the transmission failed, I remembered sometimes the car would move a bit when I shifted into 1st at a stop. I didn't think much of it, but come to realize it was probably my clutch not disengaging 100% so there was always a little bit of force on each gear when I shifted. 4 or so track days later shifting at 7k = blown synchros = 0A3 swap = putting a new clutch disc on and reusing my pressure plate because I'm retarded. The new clutch disc added just enough thickness for the pressure plate to pass the threshold of going into gear with the engine running and not going into gear. Too bad it took me this long to notice, otherwise I wouldn't have toasted my transmission.
Not sure where I'm going with this... that's the story of how I broke my B7 and why I think my clutch slave is installed and bled correctly lol

[Cgoon009]

My clutch hydraulic system was already bled 100%. With the line still connected to the slave, I tried reinstalling it several times. Every time it missed the clutch fork the pedal had absolutely no play and was rock-hard from the beginning. When I installed it the right way, I could feel the slave piston compressing as I pushed it in and then the pedal would feel normal until the last 2" of the throw and it would turn into a rock. This was because the slave had maxed out, but the clutch had not fully disengaged. I knew this because when the engine was running I could not shift into any gear. But if I put it in gear, clutched in, and then started the car, I could release the clutch and get the car to drive around. But if I went back into neutral, I couldn't get it back in gear. The clutch was so close to being fully disengaged that I could drive it if I started it in gear, but couldn't actually put it in gear with the motor running. I think I had a premature pressure plate failure and that was the cause of my synchros getting destroyed at only 60,000 miles. When I was driving my car around before the transmission failed, I remembered sometimes the car would move a bit when I shifted into 1st at a stop. I didn't think much of it, but come to realize it was probably my clutch not disengaging 100% so there was always a little bit of force on each gear when I shifted. 4 or so track days later shifting at 7k = blown synchros = 0A3 swap = putting a new clutch disc on and reusing my pressure plate because I'm retarded. The new clutch disc added just enough thickness for the pressure plate to pass the threshold of going into gear with the engine running and not going into gear. Too bad it took me this long to notice, otherwise I wouldn't have toasted my transmission.
Not sure where I'm going with this... that's the story of how I broke my B7 and why I think my clutch slave is installed and bled correctly lol

Yeah that's a huge bummer, but a valuable lesson. I recently did a slave after an axle let go and cut the line and mangled the pin connection. We missed it the first couple times and the pedal would travel half way but with no feed back at all, and then hit a wall. The car has an aftermarket clutch, so maybe that's where the difference is. It took me a few tries but I got it going in from underneath.

If the op is hitting the slave spot on then I think your right, the pp is whats fucked. I agree with you that damaging a clutch fork is really unlikely.

[aysix]

I'm threadjacking for a moment since well, OP's shit is fucked. My buddy and I are trying to figure out what's up with his clutch problem.

What would cause a pedal not to return by hydraulic pressure? The car runs and drives great, only we need a bungee cord on the pedal for it to return. Other than that it operates as normal. I changed the slave with a good one and it's the same thing.

We remove the bungee and the pedal slams down to china. No matter how much we bleed it, the pedal drops it like it's hot as if there's no fluid in the system at all. It was fine until a shop in CA changed the JHM clutch out for a FX300. What is it fam?

[b7_Andy]

Has to be something to do with the hydraulic system by the sound of that... if you've already replaced the slave, the only thing left would be the clutch master cylinder.


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[Cgoon009]

Has to be something to do with the hydraulic system by the sound of that... if you've already replaced the slave, the only thing left would be the clutch master cylinder.


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yeah 2x, any visible fluid leaks under the car or in the battery tray? If its not outwardly leaking, pull the kick panel and check the master.

Also worth looking at the spring on the pedal, make sure its seated and not mangled.

[aysix]

yeah 2x, any visible fluid leaks under the car or in the battery tray? If its not outwardly leaking, pull the kick panel and check the master.

Also worth looking at the spring on the pedal, make sure its seated and not mangled.

No visible leaks, spring looks good. Guess it's time for a new master. I don't reckon it's the PP.

[luciddream]

I've been dealing with a very similar situation for about two weeks. Changed the slave cylinder and now the way master cylinder. Turns out, the Southbend stage 3 clutch uses a longer throw out bearing than stock. I will be pulling the transmission out soon to do the work. It's being done in Longmont. OP, did you install an aftermarket clutch?

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[b7_Andy]

So just measured my clutch fork spacing before and after changing my clutch. This is the distance that I measured:
With the bad pressure plate that gap was 66.9mm. After installing the new pressure plate the gap is now 55.7mm. I haven't put the motor back in to see if the clutch works properly, but as of right now I have a brand new clutch disc, pressure plate, throwout bearing, clutch fork, clutch fork intermediate plastic piece, and slave cylinder. So I assume the 55.7mm is a good reference for the clutch fork spacing. I will update when the car's running. Also here's some pictures of the pressure plate... old:
New: