applejak_2000

Went to start my 2004 Civic DX (194,000 mi) Monday morning . The clutch pedal was very stiff and didn’t want to go all the way to floor so I could start it. .(This problem cropped up overnight no symptoms like this ever before, which seems odd). Pumped the pedal four or five times till it finally depressed far enough to allow it to start. Checked fluid, it was low so I topped it off (but it doesn’t seem to be leaking - monitoring it frequently over these last four days or so). After driving awhile it gets better but not up to 100% as it should be, more like 94% or so.When it is warmed up, it behaves fairly good, not too stiff but you can tell something is just not quite right. Length of clutch pedal travel will seem just a little bit off when it's warmed up. Every time it is left to cool off it goes right back to being very stiff and needs pumped 4-5 times - but then will be pretty much fine after the clutch has warmed up through driving for awhile. Gears don’t grind so it’s engaging and disengaging ok, I guess. Acceleration through gears seem fairly normal. I'm assuming the clutch and hydraulic system are warming up through using the pedal, moving & compressing the fluid, the friction on the disk, and engine heat spreading through bell housing. So this seems to be a problem accentuated primarily when cold.
What could be wrong?
hopefully I've not been too wordy, but I'm trying to include every problem detail I can think of.

mikey1

i would start by bleeding the system,

if it got low on fluid there is a chance some air got in there

applejak_2000

I'll try that. But I think if it were air in the hydraulic line the effect would be the opposite: pedal mushy - just like what happens with brakes. Here in this case: the pedal always starts out stiff when cold - and never mushy at any time.

ezone

You might be able to use a prybar to work the throwout fork, to check that the clutch movement there is okay both when the pedal doesn't work and again after it does work, that could eliminate the clutch and pressure plate and throwout bearing and snout as potential causes. (high mileage can wear the snout the TO bearing slides on)

If the clutch feels ok when worked by hand mechanically, that would leave the hydraulic system as the prime suspect.


I'm gonna take a wildass guess at the clutch master cylinder..... the internal return spring may have broken and fallen out of place causing it to jam the piston.

applejak_2000

Possibly, but I wonder why, then, does it work nearly normally when the clutch is warmed up? A broken return spring would behave whether hot or cold.

ezone

You got a better idea?


Once you figure out which piece fixes the problem, you can then take it apart to find out what happened inside to make it fail, and update the thread with the answers.