Why is my clutch pedal farting?

[97GST6bolt]

No joke.. it's seriously making this farting noise while it gets suck into the floorboard on it's own! :thumbdown

I just replaced the clutch slave cylinder (replaced master 2 weeks ago), and I've bleeded the system over and over using one person in the car pumping the pedal 3 times and holding it while I loosen the bleeder valve and tighten it as soon as fluid comes out. I've done this for about 2 hours and it still sinks to the floor. It'll hold pressure but if you barely push in the clutch, it farts all the way to the floor. WTF?

When it holds pressure I can BARELY get it into gear, but then it looses pressure sporatically and falls to the floor. Do you think there is STILL air in the lines? Is there a better way to bleed this system? I know everything is tight and sealed, no leaks... are the acumulator valves known to cause this??

Thanks guys!

 

[miteclgst]

it seems like the noise would be caused by a leaking seal, and if you could hear this from inside the car then I would imagine that it might be the clutch master cylinder. I know you said that you replaced it a little while ago but if you bought a rebuilt piece it could have scoring on the inside of the cylinder walls that would allow the clutch to leak. I had a similiar problem with mine in that the pedal would drop to the floor, I believe the "technical term" is ghost pedal. Here is RRE's solution to the problem click here about 3/4 of the way down the page. Like they suggest you might some how have gotten some dirt in the master and that could be causing your problem. I dunno it's worth checking into.

 

[luv2rallye]

You almost certainly still have air in the lines since you "BARELY get it into gear, but then it looses pressure sporatically and falls to the floor".

Your bleeding proceedure is not correct for a system that was completely air exposed. Place a clear plastic tube over the bleeder and into a jar partially filled with brake fluid. Keep the tube end under the surface of the fluid at all times so no air can get sucked back in. Do the following in this order: Open the bleeder 1/4-1/2 turn. Have someone push the pedal to the floor once and hold it there (you should see fluid and air coming out). Close bleeder. Release pedal (pull back up if stuck). Repeat this until no air comes out - only fluid. Make sure you don't run the clutch reservoir dry (check every couple pushes) - the bottom must always be covered in fluid - don't let it see air.

This should do it but if you still have air, you can now do the following which I think you were trying to do. But this method doesn't work if the system was completely air exposed - you must do the method above first (and it is really used only for brakes). Hook up the tube and jar like above. Have someone press the clutch down and up 5 times ending with holding down. Open the bleeder to let any air out (and fluid) and immediately shut it. Repeat till no air. Then have person slowly press pedal down telling you when they start, get to middle, get to end. When they are at middle and still pressing, open and close bleeder. This will remove any air that may have got in while they were holding pedal down before.

That's it. You shouldn't even need method 2 for a clutch. If you still have air, you've got a leak somewhere. If clutch doesn't work perfectly you've got other problems. If everything works but still get farted, try putting some grease on the rod that goes from the pedal through the boot.