Clutch doesn't totally disengage.

[rfmarz@frontiernet]

After driving my car only a mile or so it became evident that it is difficult to put the car into first gear as the clutch doesn't totally disengage. I can engage third gear easily. This is right from the factory. Is this a common problem and how should it be corrected? I'd hate to adjust the clutch and find that it doesn't completely engage with the resulting burning of the plates.

[bolus]

Mine completely disengages after about 3/4 full pedal travel (which is good because I'm short).  I'm not sure how to adjust it but would be interested in hearing how it is done

[Karl]

rfmarz, depending on the position of your pedal box, your clutch might actually completely engage, then re-engage, through its entire motion of travel.  We discovered this on a K20A Atom on the dyno, with the pedal box all the way forward - if you pushed the clutch all the way to the clutch stop, it was too far.  Try driving around and finding the sweet spot where the clutch has disengaged just enough, rather than pushing it all the way in.

[Monza]

this is the reason why there is a clutch stop on every UK Atoms since about a year or more.

[Karl]

Brammo Atoms get a clutch stop too, but it seems to be adjusted to having the pedal box in the fully-forward position.

[rfmarz@frontiernet]

Karl, with the clutch pedal pushed ALL the way forward, it did not completely disengage. I am wondering if it is simply a mechanical adjustment at the end of the clutch pedal or at another location.

[Karl]

rfmarz, my car is the same way - full disengagement of the clutch occurs at approximately 3/4ths of the total pedal travel (from 'unloaded' to 'fully depressed on the stop').

[DarthChicken]

its possible the clutch just needs bled.

[rfmarz@frontiernet]

I don't know how to do this but I can tell you that this clutch slowly letting out is a REAL problem!

[Terry Kennedy]

[quote="rfmarz"]
I don't know how to do this but I can tell you that this clutch slowly letting out is a REAL problem!
[/quote]

On the driver's side of the car at the front of the engine is a small nipple. That's the clutch bleed screw. Put a piece of clear plastic hose which ends in a jar or glass on it and turn it 1/4 to 1/2 turn to the left, then have someone push the clutch pedal in. Fluid (and bubbles) will come out of the fitting and run through the hose to the jar. Tighten the nipple before they release the pedal. Normally one pass will clear this up for a while.

In my case, Brammo and I decided that I had a bad clutch master cylinder, so I have a new one here but to be honest I haven't replaced it yet - you get used to the problem. Just remember to take the shifter out of gear and release the clutch instead of keeping the clutch pedal depressed.

[1965Cobra427]

Changing out the master cylinders is really easy. I replaced both brake master cylinders when I upgraded from Sport to Track brake package. Removing the cowl panel (3 screws and the mirrors) makes it SO simple and easy to get to. Of course the bleed process will follow the replacement. If a replacement is needed, Brammo usually provides detailed instructions.

[rfmarz@frontiernet]

Is the fluid coming out #40n brake fluid? I'll have to try what Karl said. If I'm feeling it right, the engagement point changes from ~ half way out to fully depressed in a few seconds, HOWEVER, when I put it into neutral, and blip the throttle, the clutch engagement seems normal again. Weird.

[Mr.Woolery]

[quote="rfmarz"]
Is the fluid coming out #40n brake fluid? I'll have to try what Karl said. If I'm feeling it right, the engagement point changes from ~ half way out to fully depressed in a few seconds, HOWEVER, when I put it into neutral, and blip the throttle, the clutch engagement seems normal again. Weird.
[/quote]

If your engagement point changes over time, it's probably either air in the system or a master cylinder allowing blow-by.  First try a thorough bleeding of your clutch line system.  If that doesn't solve the problem, you may need to replace the master cylinder.  In either case, you have the time, I'd also take this as an opportunity to replace the bleed screw and install a Speedbleeder--this'll make futher bleeding of the circuit a lot easier.

[maverick1]

Spaz, do you know which Speedbleeder model we need for the Atom? Does it vary if you have the Wilwoods or Alcons?
Cheersâ?¢

[AndyLUFC]

[quote="The Masked Spaz"]
[quote="rfmarz"]
Is the fluid coming out #40n brake fluid? I'll have to try what Karl said. If I'm feeling it right, the engagement point changes from ~ half way out to fully depressed in a few seconds, HOWEVER, when I put it into neutral, and blip the throttle, the clutch engagement seems normal again. Weird.
[/quote]

If your engagement point changes over time, it's probably either air in the system or a master cylinder allowing blow-by.  First try a thorough bleeding of your clutch line system.  If that doesn't solve the problem, you may need to replace the master cylinder.  In either case, you have the time, I'd also take this as an opportunity to replace the bleed screw and install a Speedbleeder--this'll make futher bleeding of the circuit a lot easier.
[/quote]

Finally got round to replacing the master cylinder yesterday and the clutch is now perfecto! It was certainly this that was causing the partial disengagement problem and the lottery as to where the clutch would bite. Apart from some minor DOT4 bukkake, about 10 minutes.