Just replaced my CMC (clutch master cylinder) because when I drive the pedal acts like it lags a lot. The cmc is the most updated one from honda because they have been apparently having issues with the diaphram or something like that. Worked fine right after putting in but 2 days later I get in and go and get a lot of lag from it in-between shifts. When I turn the car off with clutch pedal in I take my foot off and it sits there for a second and then shoots out. I bled it a lot and it is shooting a solid stream from the slave cylinder. Would it be the slave that is causing the issue or maybe the CMC? Either way when I am on a hill at a dead stop It releases so slow that I almost run into the car behind me or I burn the heck out of my clutch. Any info would be appreciated.

 

Re-bleed your clutch master cylinder/slave cylinder.

 

Rebled it and it worked at least for a little bit until it warmed up all the way. Seems that it mainly happens when the engine is warm. Any ideas?

 

if i had to guess i would say there's something wrong with the clutch itself, it could be warped or the flywheel could be warped...as it warms up and the metal components expand it makes the issue worse, similar to warped rotors

you could try replacing the slave cylinder first just in case it has something going on with it, you normally want to replace the cmc and sc in pairs anyhow

 

so I found out the slave cylinder was brand new and the shop had put it in without telling me. So clutch is brand new, same with slave and cmc. The shop looked at it again and bled it a few more times and then dropped the tranny out to bleed the clutch internally but it is still having the issue. I was driving it the other day and the clutch took almost four seconds to disengage and I almost got hit by another car because of it. Any thing else y'all could think of?

 

The cmc is a brand new most recently updated honda cmc as well.

 

Do the '09 Si's have an accumulator inline with the clutch line? Could be a bad accumulator or a pinched line.

 

I didn't see one when I swapped out the cmc and cant find anything on Google if there is one. Lines were inspected and they said they were all good. Its weird with all the hydraulics replaced and when you turn the car off the pedal sticks to the floor for like 3 seconds then springs out

 

Like..weird lol If you've replaced and confirmed the master and slave are good then its either a problem with the line or the clutch.
Could be the accumulator is there is one or it could be a problem with the clutch fork and it's pivot ball stud, either that or a problem with your pressure plate.
Try taking compressed air and a blow gun to the clutch line, disconnect the line from both the master and slave obviously.

 

Over extending? Master cylinder adjustment? You could try to give it more slack. See how far you can shorten the rod before it creeps, and lengthen it just so it doesn't. You could try that.

So you had a clutch put in, they put a slave in without telling you, and then you put a master in, and then they removed the transmission again? Break down this scenario again...

 

how much clutch free play do you have ? should be about a half inch or so, you may have too much or not enough

 

If it is over extending the diaphram, it may have not enough freeplay. Not certain, but on older models there is an adjustment on a switch that you can tighten or loosen for freeplay, so that alone may not be a determining factor if it is in fact over extending.