Duel disk clutch job - What am I getting myself into?
06-06-2006, 12:02 PM
#196
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Originally Posted by GlenL
Is the throwout bearing guide tube bent?
06-06-2006, 12:05 PM
#197
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Have you bled the master using the inside the car method? Almost impossible to bleed that sucker any other way. Remove the clutch pedal mech. Pull the circlip on the master cylinder to allow it to travel into the cockpit. When you see that fluid is passing out the clylinder is bled. Push it back in and reinstall the clutch pedal. Should be rock hard.
Originally Posted by Hacker-Pschorr
It all started here:
https://rennlist.com/forums/showthread.php?t=268926
I've noticed since that thread I can tell when the clutch is not disengaged by pedal feel. This seamed like a hydraulic issues since what mechanically in the clutch could “come and go” causing the pedal feel to be firm / soft at random?
Well today it stopped working 100% - I cannot disengage the clutch at all. I popped the hood, on the brake booster was brake fluid. Not much, just a drop or two. The reservoir is full, so it’s not low on fluid. Something in the clutch hydraulic system backed up causing fluid to either **** out the cap or maybe a leak in the blue hose?
The clutch master, slave, pressure line and blue hose are only a few years old. What the heck would cause this? The only part of the clutch I’ve been in contact with is the slave – wrestling with it to remove it in order to install a flywheel lock tool.
Is there anyway I could have damaged the slave in such a way it is causing the fluid in the system to back up? I dunno, I’m totally lost here. Right now pushing in the clutch pedal takes almost no effort – no pressure on the other end.
I could just replace the master / slave (again) but I would really like to understand what is going on. Any idea out there? I finally dialed in the fuel system for the supercharger, and now I cannot drive the car, this is killing me!!!
EDIT - I have not changed anything since starting the thread above. The car has been sitting (check the weather) since then. I finally took the car out Sunday - it was working fine so I took it to work yesterday. That is when everything went south.
https://rennlist.com/forums/showthread.php?t=268926
I've noticed since that thread I can tell when the clutch is not disengaged by pedal feel. This seamed like a hydraulic issues since what mechanically in the clutch could “come and go” causing the pedal feel to be firm / soft at random?
Well today it stopped working 100% - I cannot disengage the clutch at all. I popped the hood, on the brake booster was brake fluid. Not much, just a drop or two. The reservoir is full, so it’s not low on fluid. Something in the clutch hydraulic system backed up causing fluid to either **** out the cap or maybe a leak in the blue hose?
The clutch master, slave, pressure line and blue hose are only a few years old. What the heck would cause this? The only part of the clutch I’ve been in contact with is the slave – wrestling with it to remove it in order to install a flywheel lock tool.
Is there anyway I could have damaged the slave in such a way it is causing the fluid in the system to back up? I dunno, I’m totally lost here. Right now pushing in the clutch pedal takes almost no effort – no pressure on the other end.
I could just replace the master / slave (again) but I would really like to understand what is going on. Any idea out there? I finally dialed in the fuel system for the supercharger, and now I cannot drive the car, this is killing me!!!
EDIT - I have not changed anything since starting the thread above. The car has been sitting (check the weather) since then. I finally took the car out Sunday - it was working fine so I took it to work yesterday. That is when everything went south.
06-06-2006, 12:32 PM
#198
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Originally Posted by JE928Sx4
Have you bled the master using the inside the car method? Almost impossible to bleed that sucker any other way. Remove the clutch pedal mech. Pull the circlip on the master cylinder to allow it to travel into the cockpit. When you see that fluid is passing out the clylinder is bled. Push it back in and reinstall the clutch pedal. Should be rock hard.
I know someone else in this thread mentioned something about doing this. How do you keep from dumping brake fluid all over the interior? I'm not fully sure I understand how / why this works. If there is air trapped in the slave or the lower lines, how does this force it out?
06-06-2006, 12:45 PM
#199
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You bleed the slave and lines from the master to slave through the slave. The problem with the master is that the blue hose connects below the top of the master leaving a space in front of the piston for air to collect. Put some paper towels around the bottom of the master, remove the circlip, slowly retract the piston until it can tip (don't use force to tip it because you can scratch the bore), tip it downward so that air/fluid can get out over the top, burp it once or twice, then reassemble it all.
You can run the blue hose around the fender side of the booster to avoid having a dip.
You can run the blue hose around the fender side of the booster to avoid having a dip.
06-06-2006, 12:48 PM
#200
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Originally Posted by SharkSkin
Erik,
Is there more than one slave cylinder available? If your replacement has a larger bore than what it should be, you will not get enough travel. Same goes if the clutch master has a smaller bore than what it should be. You should be getting 17.4mm of travel at the slave. Can you verify this through the inspection hole? WYAIT the tip of the release arm should be 17.4mm behind the rear edge of the inspection hole.
Is there more than one slave cylinder available? If your replacement has a larger bore than what it should be, you will not get enough travel. Same goes if the clutch master has a smaller bore than what it should be. You should be getting 17.4mm of travel at the slave. Can you verify this through the inspection hole? WYAIT the tip of the release arm should be 17.4mm behind the rear edge of the inspection hole.
06-06-2006, 12:51 PM
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It's really not that hard with a pressure bleeder at about 5-10 psi (I use the one 928 Spec sells.), and when the fluid starts to seep it is easily pushed back in and held in place with the clutch pedal push rod while you reinstall the circlip. The only way to insure a rock hard clutch pedal. I learned this one from Kempf.
Originally Posted by Hacker-Pschorr
That sounds like fun
I know someone else in this thread mentioned something about doing this. How do you keep from dumping brake fluid all over the interior? I'm not fully sure I understand how / why this works. If there is air trapped in the slave or the lower lines, how does this force it out?
I know someone else in this thread mentioned something about doing this. How do you keep from dumping brake fluid all over the interior? I'm not fully sure I understand how / why this works. If there is air trapped in the slave or the lower lines, how does this force it out?
06-06-2006, 01:46 PM
#202
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Originally Posted by JE928Sx4
It's really not that hard with a pressure bleeder at about 5-10 psi (I use the one 928 Spec sells.), and when the fluid starts to seep it is easily pushed back in and held in place with the clutch pedal push rod while you reinstall the circlip. The only way to insure a rock hard clutch pedal. I learned this one from Kempf.
Off to Sears to buy a snap-ring pliers
Before ripping my clutch out (and before swapping out the master / slave) I clamped off the rubber hose between the master & slave. There was zero clutch pedal movement. If there was air trapped in the master, wouldn't I have felt it give a little? I actually ended up busting that rubber line while it was clamped - so my old master was working fine.
06-06-2006, 01:49 PM
#203
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Originally Posted by Hacker-Pschorr
Good idea - my only counter-thought is this. If it was something mechanical like that, wouldn't the problem be consistant? I could drive for miles with no issues, then all of a sudden - total lockup.
Originally Posted by Hacker-Pschorr
I have a bellhousing like that - need to dig it up. Problem is, it only "acts up" or at least I can only tell it's happening when the car is nice and warm. Not sure I want to climb under there with a red hot exhaust (time to see if anyone I know has a lift........ 
). Keep in mind, this is still happening after replacing both the master & slave.
). Keep in mind, this is still happening after replacing both the master & slave.If you're seeing inconsistent or insufficient travel then follow the bleeding tips in other posts here. Air in the system, insufficient clearance on MC rod when pedal is released or expanding flex hose(pressure side) are the other things that can affect travel. IIRC you have a new hose and have checked the clearance at the rod repeatedly. So you have to absolutely eliminate air as a possible factor. For the master, remove all DS carpet, etc. and when you're done clean up real thoroughly with simple green, brake clean, etc so the brake fluid doesn't get a chance to eat the paint. Be very, very careful as the piston seals on this type of part are easily damaged.
06-06-2006, 01:54 PM
#204
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Originally Posted by FlyingDog
The WSM has nice instructions for measuring all of that. It's too bad the real measurements are completely different. The front of my release arm is in front of the inspection hole and always has been. My discs are only worn ~.3mm and the metal surfaces are worn less than .1mm.
06-06-2006, 01:56 PM
#205
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Originally Posted by Hacker-Pschorr
even with only 10psi - I cannot imagine what would keep fluid from pissing all over the interior.
Off to Sears to buy a snap-ring pliers
Before ripping my clutch out (and before swapping out the master / slave) I clamped off the rubber hose between the master & slave. There was zero clutch pedal movement. If there was air trapped in the master, wouldn't I have felt it give a little? I actually ended up busting that rubber line while it was clamped - so my old master was working fine.
Off to Sears to buy a snap-ring pliers
Before ripping my clutch out (and before swapping out the master / slave) I clamped off the rubber hose between the master & slave. There was zero clutch pedal movement. If there was air trapped in the master, wouldn't I have felt it give a little? I actually ended up busting that rubber line while it was clamped - so my old master was working fine.
Another thought just occurred to me -- IIRC there are two early intermediate plates avalable, one is located by a ridge on mating parts, the other is located by pins on the mating part(a little unclear on the details, sorry). Are you sure you have the right one?
06-06-2006, 02:02 PM
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Believe me, go slow and it willjust seep, then push it back in.
Maybe depending on how the air is trapped, but you'll never know until it's set as it would be for driving and bled properly, and only the inside the car method truly works.
Maybe depending on how the air is trapped, but you'll never know until it's set as it would be for driving and bled properly, and only the inside the car method truly works.
Originally Posted by Hacker-Pschorr
even with only 10psi - I cannot imagine what would keep fluid from pissing all over the interior.
Off to Sears to buy a snap-ring pliers
Before ripping my clutch out (and before swapping out the master / slave) I clamped off the rubber hose between the master & slave. There was zero clutch pedal movement. If there was air trapped in the master, wouldn't I have felt it give a little? I actually ended up busting that rubber line while it was clamped - so my old master was working fine.
Off to Sears to buy a snap-ring pliers
Before ripping my clutch out (and before swapping out the master / slave) I clamped off the rubber hose between the master & slave. There was zero clutch pedal movement. If there was air trapped in the master, wouldn't I have felt it give a little? I actually ended up busting that rubber line while it was clamped - so my old master was working fine.
06-06-2006, 02:06 PM
#207
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Originally Posted by SharkSkin
I recommend that you NOT clamp the new line, just on g.p.
Originally Posted by SharkSkin
Another thought just occurred to me -- IIRC there are two early intermediate plates avalable, one is located by a ridge on mating parts, the other is located by pins on the mating part(a little unclear on the details, sorry). Are you sure you have the right one?
JE - If I'm home early enough, I'll try the bleed from the inside idea. What have I got to loose at this point?
06-06-2006, 02:39 PM
#208
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I just thought of something. With the height the front of my car is right now (on ramps) the blue hose nipple is now above the piston rod side of the master (or actually, the front of the master where the steel line is now at the top). So in order for this to work, I should probably lower the car.
06-06-2006, 09:46 PM
#210
Burning Brakes
Hacker,
I don't think the height of the front while on ramps will be a big issue. I agree with Dave, lets find out whether it's mechanical or hydraulic. The method I mentioned before regarding slave rod travel does not require that the car be running. You may have to work near hot pipes if you elect to drive the car undil clutch begins to drag before measuring travel. No extraordinary bravery required...
Regarding the clutch disc orientation, I recall that you do have a new clutch, but did you (by chance) install the discs backwards during this last install (when you swapped the splined shaft). To check, release clutch and look at the flywheel disc. If you can see a small gap (with springs slightly visible) this is the proper disc. No need to remove the clutch pac to do this but the bell may have to be removed.
I don't think the height of the front while on ramps will be a big issue. I agree with Dave, lets find out whether it's mechanical or hydraulic. The method I mentioned before regarding slave rod travel does not require that the car be running. You may have to work near hot pipes if you elect to drive the car undil clutch begins to drag before measuring travel. No extraordinary bravery required...
Regarding the clutch disc orientation, I recall that you do have a new clutch, but did you (by chance) install the discs backwards during this last install (when you swapped the splined shaft). To check, release clutch and look at the flywheel disc. If you can see a small gap (with springs slightly visible) this is the proper disc. No need to remove the clutch pac to do this but the bell may have to be removed.