Clutch loses pressure

[Krudges]

I have a 1994 Laser (2L w/o turbo). Recently when I was driving it, the clutch pedal went soft and wouldn't disengage. I tried to bleed the system and noticed that once I pumped up the system, the clutch would disengage and hold (pressure won't decrease), however once I released the clutch and tried to press the clutch again, the pressure was once again inadequate to disengage the clutch. Once I had the car towed home, I noticed (thanks to your forums) that the master cylinder was leaking so I rebuilt both the slave and master cylinders. However, I still have the same problem - pump up the system and it holds pressure and disengages the clutch but once the clutch is released the pressure is not adequate to disengage again without pumping. Any clues that can help? I don't see any leaks in the lines

 

[romeen]

It may be a long shot but make sure you don't have a leak at the bleeder valve. Also make sure you tightened it back up properly.

 

[thrdtryGSX]

Did you fill the master and slave cylinders with fluid before the install, then try to bleed them? Or did you install them dry?

 

[Krudges]

I did not fill the cylinders before the reinstalling them. What I can't figure out is why the system will hold pressure as long as the clutch is depressed (after pumping up the system) unless the master cylinder cannot maintain the pressure once the pedal is released (which is why I rebuilt it)

 

[thrdtryGSX]

Are you letting the air out at the bottom? http://www.dsmtuners.com/forums/showthread.php?t=60319
I would fill the master and slave up with fluid and try properly bleed the system. If you have a Chilton's repair manual (which I highly recommend) it is chapter 7 page 39. If it still does not work after that check your rebuild again and make sure one of the o rings is not damaged and that all of your springs are in their right place.

 

[romeen]

I did not fill the cylinders before the reinstalling them. What I can't figure out is why the system will hold pressure as long as the clutch is depressed (after pumping up the system) unless the master cylinder cannot maintain the pressure once the pedal is released (which is why I rebuilt it)

It sounds like air is being drawn into the system when you release the pedal.

 

[knighteclipse1]

check and see if you have fluid loss from the slave cylinder. Possible loss of fluid under the dash, it might not be really noticeable so look good. Just because you had them rebuilt doesn't mean they aren't the cause of the problem.