Clutch not disengaging???
Hey everyone, looking for some insight before I start throwing parts at this.
Setup:
- Stage 2 clutch (very stiff pedal)
- K-Tuned CMC & CSC
- Acuity Shifter Bushings
Main issue:
Clutch will NOT disengage when the car is ON, but works perfectly fine when the car is OFF.
- With engine OFF → goes into all gears smoothly
- With engine ON → won’t go into gear at all
- Forcing into gear starts to stall the car
- Only way to move it is to start the car in gear
Important behavior:
- Happened after:
- stop-and-go traffic
- after spirited driving
- The first time it happened I let the car sit and cool down (hours or next day), the clutch worked completely normal again
Clutch feel:
- Engagement point is normally pretty close to the floor
- Pedal is stiff (stage 2 clutch), hard to tell if it’s “spongy”
- Slave cylinder appears to move when pressing the pedal (from visual inspection)
Fluid condition:
- Fluid in reservoir is dark/golden-brown
- Has visible particles in it
- Has NOT been flushed recently
Other relevant info:
- I accidentally drove with the parking brake partially engaged recently and overheated the rear brakes pretty badly (they were glowing)
- Issue started happening after that
- Happened again even without parking brake, just in normal traffic.
Transmission info:
- 2nd gear is already bad (basically neutral), but this issue is affecting ALL gears
- Trans shifts fine with engine OFF, so I don’t think it’s internal
What I’ve checked:
- No visible leaks from CMC
- Slave cylinder moves when pedal is pressed
- No obvious loose components
- Shifts perfectly with engine OFF
What I think it is:
Leaning towards:
- Air in clutch system / contaminated fluid boiling when hot
- Possibly failing CMC or CSC
- Engagement point shifted possibly and the cars safety mechanism (if any) won't let me go into gear with out proper disengagement of the clutch (Only a theory, hasn't been tested)
I do NOT think it’s the transmission, since:
- It works fine cold
- Problem comes and goes with heat
Plan:
- Full clutch + brake fluid flush (fresh DOT 4)
- Proper bleed
- If issue persists → replace CMC, then CSC if needed
Question:
Does this sound like classic hydraulic failure (boiling fluid / bad master), or has anyone seen something similar that ended up being something else?
Videos attached of pedal + slave movement.
Also, my clutch pedal is normally that loud. I don't know why. The noise went away for like a week a few months ago when I disassembled and reassembled the clutch pedal assembly, put a brace on it, lubed the CMC plunger rod with white lithium grease, and put in a new clevis and cotter pin.