928 GTS Clutch Drag (update) & Question
#16
Rennlist Member
Two points, I just went through a CMC and pilot bearing change and bled using the factory procedures, no problems what so ever:
1. Did you lube the guide tube and short drive shaft with the Porsche special grease? If not, the clutch will bind on the shaft.
2. Is the plastic ball socket bushing on the release lever in good shape? Mine had failed and was causing some engagement problems.
Oh, just ignore Roger, the 5-speed is the only way to go fast!
1. Did you lube the guide tube and short drive shaft with the Porsche special grease? If not, the clutch will bind on the shaft.
2. Is the plastic ball socket bushing on the release lever in good shape? Mine had failed and was causing some engagement problems.
Oh, just ignore Roger, the 5-speed is the only way to go fast!
#17
Instructor
Thread Starter
Two points, I just went through a CMC and pilot bearing change and bled using the factory procedures, no problems what so ever:
1. Did you lube the guide tube and short drive shaft with the Porsche special grease? If not, the clutch will bind on the shaft.
2. Is the plastic ball socket bushing on the release lever in good shape? Mine had failed and was causing some engagement problems.
Oh, just ignore Roger, the 5-speed is the only way to go fast!
1. Did you lube the guide tube and short drive shaft with the Porsche special grease? If not, the clutch will bind on the shaft.
2. Is the plastic ball socket bushing on the release lever in good shape? Mine had failed and was causing some engagement problems.
Oh, just ignore Roger, the 5-speed is the only way to go fast!
#18
Rennlist Member
Bushing replacement...
I followed this procedure and it worked well for me:
https://rennlist.com/forums/928-foru...ml#post8286119
#19
Rennlist Member
I hate the factory CMC!
I put a floor mount wilwood system in my conversion car for this reason. It took 4 pumps of the pedal and the system was bled, no more issues EVER.
However that said, with everything in the car, remove the C clip, and slowly pull out the piston, once the primary seal is nearing the top tip it back and allow the air to escape that way. It is a much better way to do it!
I put a floor mount wilwood system in my conversion car for this reason. It took 4 pumps of the pedal and the system was bled, no more issues EVER.
However that said, with everything in the car, remove the C clip, and slowly pull out the piston, once the primary seal is nearing the top tip it back and allow the air to escape that way. It is a much better way to do it!
#21
Archive Gatekeeper
Rennlist Member
Rennlist Member
I have great difficulty with anything under the dash, the knee bolster has to come out of the way. Colin, can you wear Lewis Hamilton's suits?
I'm probably the only one who has had trouble with it, but the snap ring holding the CMC piston in is pretty small. I had a tough time with the 'regular' size internal snap ring pliers (5-6" overall length) compressing the thing enough to get it out. Took some finagling with a small flat blade 'helper' screwdriver. I subsequently bought a smaller pair of Craftsman snap ring pliers but have not had to open another CMC yet so I'm not sure whether they're the solution or not.
I'm probably the only one who has had trouble with it, but the snap ring holding the CMC piston in is pretty small. I had a tough time with the 'regular' size internal snap ring pliers (5-6" overall length) compressing the thing enough to get it out. Took some finagling with a small flat blade 'helper' screwdriver. I subsequently bought a smaller pair of Craftsman snap ring pliers but have not had to open another CMC yet so I'm not sure whether they're the solution or not.
#22
Nordschleife Master
Rob,
That might be the difference, I dont have the map tray in my car, and I normally remove it first.
However I have done it on the airbag cars too.
I am 5'11" and 170lbs
That might be the difference, I dont have the map tray in my car, and I normally remove it first.
However I have done it on the airbag cars too.
I am 5'11" and 170lbs
#23
Archive Gatekeeper
Rennlist Member
Rennlist Member
6'4", 215, size 8.5 hands, questionable eye-hand coordination, and poor judgement. Not a good combination for working in footwells, here....
#24
Instructor
Thread Starter
Success!
We reinstalled the flywheel, the clutch and back-bled the system by manually compressing and releasing the pushrod of the slave cylinder (slowly) several times. Once again, the clutch pedal had a very solid feel. This time however, there was no clutch drag. Yes!!! And I didn’t even have to shorten the CMC piston …
So winding this all back, did I need to replace the hydraulics or did an air bubble find its way into the old system? Who knows? When we disassembled the old CMC and old Slave, there was a grayish mud/paste in both cylinders. This crud had probably accumulated since the car was born. Now I won’t be thinking about the cylinders or their hoses anytime soon.
And as an added bonus, when we removed the flywheel we discovered a RMS leak which has been repaired. We also know that the clutch pack was very new (correspondence with PO) and it has been checked by Clutchmasters and given the A-OK.
At least I didn’t purchase $2500 worth of new clutch parts to discover the problem was not fixed. Good for me. Bad for the parts vendors! (Sorry guys. I'm sure you'll have future opportunities).
Thanks for all the great advice.
We reinstalled the flywheel, the clutch and back-bled the system by manually compressing and releasing the pushrod of the slave cylinder (slowly) several times. Once again, the clutch pedal had a very solid feel. This time however, there was no clutch drag. Yes!!! And I didn’t even have to shorten the CMC piston …
So winding this all back, did I need to replace the hydraulics or did an air bubble find its way into the old system? Who knows? When we disassembled the old CMC and old Slave, there was a grayish mud/paste in both cylinders. This crud had probably accumulated since the car was born. Now I won’t be thinking about the cylinders or their hoses anytime soon.
And as an added bonus, when we removed the flywheel we discovered a RMS leak which has been repaired. We also know that the clutch pack was very new (correspondence with PO) and it has been checked by Clutchmasters and given the A-OK.
At least I didn’t purchase $2500 worth of new clutch parts to discover the problem was not fixed. Good for me. Bad for the parts vendors! (Sorry guys. I'm sure you'll have future opportunities).
Thanks for all the great advice.