Clutch Bleed Issues
06-11-2015, 10:03 AM
#1
Clutch Bleed Issues
My clutch master cylinder failed, so I decided to get the zperformance tilton kit, and replace the whole system. Also replaced the slave cylinder with a centric unit (stock replacement part). Install went very well, pedal is adjusted to specs in the service manual, lines routed, was actually alot easier than some of the write-ups here warned about. No leaks, pressure tested with air compressor, blah, blah, blah.
Issue is I am having a heckuva time getting all the air out of the system. I gravity bled at first until I saw fluid dribbling out of the bleeder, then had someone pump the clutch as I began to release the bleeder until th fluid runs without bubbles. Did this for about 45 minutes and the pedal still feels spongy.
I was getting ready to vacuum bleed the system, when I saw this video on youtube, whcih makes alot of sense when you compare our setup with what the guy is describing:
My question is has anyone done this with any success? It looks like I might have to disconnect the slave from the tranny to get the clamp in place, which I would rather not do if this is ineffective. But it does sound like it would work perfectly.
Any thoughts?
Issue is I am having a heckuva time getting all the air out of the system. I gravity bled at first until I saw fluid dribbling out of the bleeder, then had someone pump the clutch as I began to release the bleeder until th fluid runs without bubbles. Did this for about 45 minutes and the pedal still feels spongy.
I was getting ready to vacuum bleed the system, when I saw this video on youtube, whcih makes alot of sense when you compare our setup with what the guy is describing:
My question is has anyone done this with any success? It looks like I might have to disconnect the slave from the tranny to get the clamp in place, which I would rather not do if this is ineffective. But it does sound like it would work perfectly.
Any thoughts?
06-12-2015, 08:52 PM
#2
New Member
There was a recent thread about this and they were saying something similar about compressing the slave to bleed the system. I did only think this was for the OEM cmc but now that you are installing the same system that i amm getting ready to install it looks as though our system with this style slave and line length it would make things alot easier. If it helps please let us know.
06-15-2015, 07:39 AM
#3
Well I tried the method he described in the vid, with little success. With the slave clamped there is really no pedal travel to build pressure to bleed the clutch.
What I would up doing was reverse bleeding, pushing the slave cylinder piston all the way in to push the air bubbles up into the reservoir and out of the system. This worked very well, after about 15 pumps there were no bubbles. I pumped it about 10x more just to be safe. Put it all back together and dammit if the pedal still does not come all the way back up.
The clutch engages and disengages fine in every gear, including reverse. Pushing down on the pedal it doesnt feel mushy, but when releasing the pedal it does not come all the way back on its own, the spring "pops" it back up at about 2/3rds of the way.
I went inside the cabin to see if I had it adjusted incorrectly, but other than the two switches and the master rod there isnt any real adjustment. What I did notice is that the return spring droops when I first depress the clutch, than as the pedal travels it compresses. I am wondering if the spring assembly is broken. It kind of looks like a mini version of a rear motorcycle suspension, where the pedal is the swingarm going up and down. I dont think it should droop at the beginning of travel.
Can anyone do me a big favor and just check to see if their spring does the same or not?
In the meantime I guess I will order a new pedal assembly, but I didnt want to spend another $100 if I didnt have to.
What I would up doing was reverse bleeding, pushing the slave cylinder piston all the way in to push the air bubbles up into the reservoir and out of the system. This worked very well, after about 15 pumps there were no bubbles. I pumped it about 10x more just to be safe. Put it all back together and dammit if the pedal still does not come all the way back up.
The clutch engages and disengages fine in every gear, including reverse. Pushing down on the pedal it doesnt feel mushy, but when releasing the pedal it does not come all the way back on its own, the spring "pops" it back up at about 2/3rds of the way.
I went inside the cabin to see if I had it adjusted incorrectly, but other than the two switches and the master rod there isnt any real adjustment. What I did notice is that the return spring droops when I first depress the clutch, than as the pedal travels it compresses. I am wondering if the spring assembly is broken. It kind of looks like a mini version of a rear motorcycle suspension, where the pedal is the swingarm going up and down. I dont think it should droop at the beginning of travel.
Can anyone do me a big favor and just check to see if their spring does the same or not?
In the meantime I guess I will order a new pedal assembly, but I didnt want to spend another $100 if I didnt have to.
06-15-2015, 02:25 PM
#4
Well I tried the method he described in the vid, with little success. With the slave clamped there is really no pedal travel to build pressure to bleed the clutch.
What I would up doing was reverse bleeding, pushing the slave cylinder piston all the way in to push the air bubbles up into the reservoir and out of the system. This worked very well, after about 15 pumps there were no bubbles. I pumped it about 10x more just to be safe. Put it all back together and dammit if the pedal still does not come all the way back up.
The clutch engages and disengages fine in every gear, including reverse. Pushing down on the pedal it doesnt feel mushy, but when releasing the pedal it does not come all the way back on its own, the spring "pops" it back up at about 2/3rds of the way.
I went inside the cabin to see if I had it adjusted incorrectly, but other than the two switches and the master rod there isnt any real adjustment. What I did notice is that the return spring droops when I first depress the clutch, than as the pedal travels it compresses. I am wondering if the spring assembly is broken. It kind of looks like a mini version of a rear motorcycle suspension, where the pedal is the swingarm going up and down. I dont think it should droop at the beginning of travel.
Can anyone do me a big favor and just check to see if their spring does the same or not?
In the meantime I guess I will order a new pedal assembly, but I didnt want to spend another $100 if I didnt have to.
What I would up doing was reverse bleeding, pushing the slave cylinder piston all the way in to push the air bubbles up into the reservoir and out of the system. This worked very well, after about 15 pumps there were no bubbles. I pumped it about 10x more just to be safe. Put it all back together and dammit if the pedal still does not come all the way back up.
The clutch engages and disengages fine in every gear, including reverse. Pushing down on the pedal it doesnt feel mushy, but when releasing the pedal it does not come all the way back on its own, the spring "pops" it back up at about 2/3rds of the way.
I went inside the cabin to see if I had it adjusted incorrectly, but other than the two switches and the master rod there isnt any real adjustment. What I did notice is that the return spring droops when I first depress the clutch, than as the pedal travels it compresses. I am wondering if the spring assembly is broken. It kind of looks like a mini version of a rear motorcycle suspension, where the pedal is the swingarm going up and down. I dont think it should droop at the beginning of travel.
Can anyone do me a big favor and just check to see if their spring does the same or not?
In the meantime I guess I will order a new pedal assembly, but I didnt want to spend another $100 if I didnt have to.
What you can try is to perform a "Clutch Adjustment" via setting the length of the rod that compresses the clutch master cylinder. You loosen the nut on the back of the fork that attaches to the pedal assy, and elongate the rod to effectively pre-load the clutch pedal/master cylinder assembly.
You will notice there is a small "dead zone," where the ratio of pedal travel to pressure build is relatively small. If you take up some of that slack, you add preload and assist the return spring on the clutch....the idea is to only do just as much as you need and not go too far as to affect clutch engagement (if you do it too much you may burn your clutch because it will remain in a semi-engaged position even with the pedal released)
06-22-2015, 10:04 AM
#5
Success!
You were correct guitman - all I needed was to add 1.5 more turns to the rod, and it is now perfect. It feels better than it has the whole time I have owned the car (I am going to attribute most of that to the new Tilton master, the SS hoses, and the new reservoir so I dont feel guilty about spending the extra money - lol).
Clutch engagement is butter smooth now, with no grabbiness (?) at all along the pedal's travel.
I'll snap a few pics of the new setup, I may still want to make a another bracket, or spend some time cleaning up the one I already made.
You were correct guitman - all I needed was to add 1.5 more turns to the rod, and it is now perfect. It feels better than it has the whole time I have owned the car (I am going to attribute most of that to the new Tilton master, the SS hoses, and the new reservoir so I dont feel guilty about spending the extra money - lol).
Clutch engagement is butter smooth now, with no grabbiness (?) at all along the pedal's travel.
I'll snap a few pics of the new setup, I may still want to make a another bracket, or spend some time cleaning up the one I already made.
06-22-2015, 01:38 PM
#6
Success!
You were correct guitman - all I needed was to add 1.5 more turns to the rod, and it is now perfect. It feels better than it has the whole time I have owned the car (I am going to attribute most of that to the new Tilton master, the SS hoses, and the new reservoir so I dont feel guilty about spending the extra money - lol).
Clutch engagement is butter smooth now, with no grabbiness (?) at all along the pedal's travel.
I'll snap a few pics of the new setup, I may still want to make a another bracket, or spend some time cleaning up the one I already made.
You were correct guitman - all I needed was to add 1.5 more turns to the rod, and it is now perfect. It feels better than it has the whole time I have owned the car (I am going to attribute most of that to the new Tilton master, the SS hoses, and the new reservoir so I dont feel guilty about spending the extra money - lol).
Clutch engagement is butter smooth now, with no grabbiness (?) at all along the pedal's travel.
I'll snap a few pics of the new setup, I may still want to make a another bracket, or spend some time cleaning up the one I already made.
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