Stuck in gear and the car is moving even if the clutch is pressed

[Gasher33]

I have one very strange situation that I think is coming from the transmission but I want to know if someone had this problem before.

Sometimes, i don't know the cause, the car is stuck in gear (mostly happens in reverse) and I can't get it out until I turn off the car, press the clutch 2-3 times (i fell like the pressure is gone in the pedal but I'm not sure) and then i can take it out of gear and everything seems to be working fine. The next strange thing is that when the car is stuck in gear, and with the clutch pressed in, if i let the brakes the car start rolling pretty quick.

Can someone help me telling me where to start looking.
Thanks

[Van_Dammesque]

A simple thing wwould be to check the gearbox fluid level.

[mmc757]

Check the clutch fluid level too. This sounds like a hydraulic problem.
Master cylinder, slave cylinder, or the lines between them.

[PhilLew]

I agree, everything you have described points towards the clutch not disengaging properly when the pedal is pressed.
A lack of fluid will do this, check the level then check for leaks before replacing any parts.

[DOH]

Agreed it's a hydraulic clutch concentric cylinder problem. Assuming that you have sufficient fluid and you seem to hint that there may no resistance on the pedal , then the first thing to do is bleed the clutch using the bleed nipple on the lower front of the gearbox bell housing.
Bleed in a similar manner as you would bleed the air out of the braking system.

[Gasher33]

Took a Christmas break but today I checked the transmission fluid and I had to add 1L. I know that the capacity is 2.8L (not good). The shifts feels way better now. I will wait to see if this issues happens again.