Getting Rid of the infamous Clutch "Shudder"

[tmontague]

I decided to take a look at this last night seeing as I had some extra time. Ever since I got my Yaris 2 years ago I would notice when I started my car in the morning for the first 10-15 mins or so until the clutch warmed up it would make a terrible shuddering noise and it felt like the engine was shaking. This only happened when releasing the clutch from a stopped position. At first I thought it was because I was not giving it enough gas, but when I started paying more attention to it I realized that this was clearly not the case.

I stumbled across this old thread http://www.yarisworld.com/forums/showthread.php?t=7929 and noticed that the issue may be the slave cylinder. I had already wanted to bleed my clutch and replace the fluid (not realizing it shared the same master cylinder as the brakes) so I figured I'd do this all at once.

The fluid itself was likely never changes but was in great condition. When bleeding the master cylinder not much air came out at all, maybe a few tiny bubbles at most. The fluid was clean. I did about 15 full clutch presses opening and closing the bleeder each time. Then I started on the salve cylinder as explained in the above link. I had a vinyl tube attached to the bleed nipple off of the salve cylinder running into a dry bottle. While leaning into the engine bay I would quickly and forcefully push in the slave piston/rod with my right hand and at the same time open the bleed nipple. I would then quickly close the nipple and then let go of the slave piston. I did this about 15 times and noticed that the fluid was darker than the rest of the system. About 10 or so really tiny bubbles came out.

I have only driven it 85km to school this cold morning but there was absolutely no shudder, even when I gave it less gas than I usually do. The clutch felt the exact same on start up as it used to 15 mins in to driving. The pedal seems to have a more linear resistance right down to the floor and a smoother operation.

Something to definitely try if you are having the clutch shudder problem. It doesn't sound like it's too good for the engine/clutch doing this year after year so it seems like a good idea to fix it. I found it hard to find any solution when googling the problem so figured I'd put a post on the forum about it. I also had noticed some clutch squeak when depressing the clutch in the past 4 months. Since I was right there I just added some lithium grease to the slave piston by pushing the boot back on it. I also applied the grease to the rectangular opening on the boot that covers the clutch fork. It's a random opening on the triangular boot but I guess what that is for since you cannot move the boot out of the way. No more squeak

Anyone know how to adjust the clutch pedal to go lower to the floor, I find the travel a bit excessive?