Calling all clutch and tranny masters

wschilawski

Member
2008 JKU 6-Speed, 123,xxx miles

About 2 months ago, I had my clutch/flywheel/pressure plate and slave cylinder replaced. After bleeding the slave, my clutch pedal was loose up to about 50% of its cycle before it started disengaging the clutch. After driving some time, it seemed to build up pressure back to where it would start disengaging the clutch, maybe 15% play. Seemed to be ok for some time…after driving on the freeway, the hydraulic system seemed to build up pressure as it was a little more difficult to push the clutch pedal. After driving through town, it would go back to normal (after a few shifts).

I was also noticing later on that there was very SLIGHT, occasional, grinding when going through gears (assuming synchros are going?)

Fast forward to last week, I got off the freeway, and after a few shifts, the hose blew off the slave cylinder and I limped to a dealership. I had the dealership replace the slave, hydraulic line, AND clutch master. After they bled it, I was back to 50% on the clutch pedal. Again, after driving, pressure built back up.

I’m heading to by friends shop tomorrow night and we’re going to go over the system again and use a pressure bleeder and try manual bleeding. I just feel there’s a bigger problem but we’re going to inspect everything.

What other things should I be looking for? I feel I have two gremlins in there that are planning something…
 

DWiggles

Caught the Bug
2008 JKU 6-Speed, 123,xxx miles

About 2 months ago, I had my clutch/flywheel/pressure plate and slave cylinder replaced. After bleeding the slave, my clutch pedal was loose up to about 50% of its cycle before it started disengaging the clutch. After driving some time, it seemed to build up pressure back to where it would start disengaging the clutch, maybe 15% play. Seemed to be ok for some time…after driving on the freeway, the hydraulic system seemed to build up pressure as it was a little more difficult to push the clutch pedal. After driving through town, it would go back to normal (after a few shifts).

I was also noticing later on that there was very SLIGHT, occasional, grinding when going through gears (assuming synchros are going?)

Fast forward to last week, I got off the freeway, and after a few shifts, the hose blew off the slave cylinder and I limped to a dealership. I had the dealership replace the slave, hydraulic line, AND clutch master. After they bled it, I was back to 50% on the clutch pedal. Again, after driving, pressure built back up.

I’m heading to by friends shop tomorrow night and we’re going to go over the system again and use a pressure bleeder and try manual bleeding. I just feel there’s a bigger problem but we’re going to inspect everything.

What other things should I be looking for? I feel I have two gremlins in there that are planning something…

It is just a simple gravity feed, manual pump hydraulic system... there is no magic here.
either air is getting into the system, one of the cylinders has a bad seal, or there is air still IN the system. :twocents: Bleed it the long, boring, proper way, dont skip any steps, dont take any shortcuts, and if that doesn't resolve the issue, have the dealer swap the parts, and try again.
 

jsukey

Member
I just went through replacing my slave cylinder. It had symptoms similar to yours. Clutch pedal started getting soft, and I started grinding gears while shifting. It went out all at once. I removed the old slave, and installed the new one onto the line. Made sure that there was plenty of fluid in the reservoir. I used a cheap Harbor Freight bleeder bottle, attached to the back of the slave. I opened the bleeder, and pushed the cylinder on the slave all the way in with my hand. A ton of air came out after several cycles. Once I saw no air bubbles, I installed the slave into the trans. I connected the bottle again, and opened the bleeder. I crawled out and slowly pushed the clutch pedal several times. Don't get in a rush. I filled up my bottle a couple of times in the process. I just closed the bleeder, emptied the bottle, and reconnected it. When I saw clean fluid in the bottle, I figured that was good enough. I closed the bleeder, and had a firm clutch. That was over 500 miles ago, and the clutch firmness is like new.
 

wschilawski

Member
What is very interesting is today after coming back from a quick trip south, the clutch felt back to normal, and my shifting improved SIGNIFICANTLY. It's as if that air worked itself out of the system. However, I'm still going to bleed one more time tomorrow to ensure all air is out of the system and that I don't introduce any more in...
 
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