The clutch pedal dropped to the floor....was no smell of burnibg clutch, just lost pressure..no fluid leaking and resevior is full. replaced slave cylinder and line 3 years ago and rebuilt master cylinder 6 years ago...everything seems to be intact. whats wrong with it..thanks

If light pressure on your clutch pedal causes it to fall or easily be pushed to the floor and you cannot feel a normal point in which the clutch should engage it is quite possibly the slave cylinder. Most mechanic shops will tell you to replace the clutch and while doing the service they will replace the slave cylinder. Do you see or smell any brake fluid leaking? Brake fluid is used in the clutch hydraulic system. So if your brake fluid is low or you can see it leaking or smell it burning this would Point towards slave cylinder. There are other ways to check if your slave cylinder is working appropriately by looking under the vehicle having the clutch pedal pushed and seeing if the cylinder is engaging the transmission and then feeling for resistance.

bad mc clutch
bad slave clutch.
can be either or both,
the hydralic clutch actuator has no adjustment other suz, older had cables, its no cable system as other states.
its auto adjusting
1: is Dot3/4 fluid leaking on either side of MC (clutch master cylinder)
2: is dot3/4 fluid leaking from the slave?
bingo fail for either leaking.
if no leaks the MC is bad, or not full of fluid.
3: does the fluid drop each weak, ( bingo for leaks)

im assuming its a vy clubsport?
Make sure you remove all the old fluid from clutch resevior and clean it out properly.
You will need to raise the vehicle on a hoist or atleast 4 cat stands .
you will need 3 people in total to get the job done correctly.
fill the clutch resevior with new fluid.
get someone to stay under the car to open slave cylinder to release air.
someone to seat to drivers seat to pump clutch pedal.
and someone at resevior all the time to top up fluid.
when bleeding system just pump the pledal slowly when the person bleeding slave cylinder says hold.hold the pedal down with light pressure when the slave is open you will get air and then little fluid .
repeat process until just good flow of fluid comes out ,once this happens you should have a good pedal..
hope this helps you

make sure that the resevior is full then have someone push down on the clutch pedal a few times and hold it down on the last stroke while you open the slave cylinder valve. then repeat as necessary until fluid comes out. Dont't let the resevior run out of fluid.

no fluid in the clutch reservoir due to a failed clutch slave cylinder
time to replace both the clutch slave and master cylinder

It's usually the clutch master or slave cylinder that is bad when the pedal drops to the floor suddenly. Check both to see which one is leaking fluid and that's your bad one.

It be a bad Clutch Slave Cylinder or it could be low on fluid. Check the reservior which is located on the engine compartment firewall and make sure is is filled to full line. if there is fluid in there than the Slave Cyclinder is bad, it is not holding pressure. Replace and it should be fine.

on the transmission there is a slave cylinder that works like a brake cylinder, when you apply pressure to the clutch pedal a rod inside the vehicle under the dash pushes into a clutch master cylinder, (almost like a brake master cylinder without the reservoir, as the clutch master cylinder works off the brake master cylinders reservoir) the plunger in the clutch master cylinder applies fluid pressure to the slave cylinder,(located down on the trans near the clutch fork assembly) which projects a piston rod into the clutch fork dis-engaging the clutch. To bleed the clutch slave cylinder locate the bleeder screw on the slave cylinder,break loose so it loosens and tightens easily. Check fluid in brake master cylinder reservoir,fill if needed, while bleeder on the slave cyl is closed have a helper push clutch pedal to floor and back 7-8 times, (At first the clutch might stay at the floor, just pull it up by hand or foot and continue) after several pumps with no rest time push pedal to the floor and hold down with foot pressure, at this time loosen the bleeder on slave untill fluid leaks out, watch for air bubbles, close bleeder and repeat untill there is no sign of air bubbles, (make sure to check fluid in the brake master cylinder and keep fill as needed, do not let fluid get less than 1/2 empty as it might **** air and you will have to start over) If this does not bring clutch to operate then you need to check if slave cylinder is reachig its full extension of push rod or not. If it is not then you will have to replace the clutch master cyl or the clutch slave cyl or both as seals are bad and wont hold pressure. Or you need to inspect the clutch fork,the throw-out bearing, or the pressure plate fingers and clutch plate for failure or broken bent parts. I hope it turns out to be a easy fix on that clutching thing.

The clutch hydraulic system is very small. Check the resevoir is full. If empty fill. Try clutch. Still problem ? Bleed the clutch slave cylinder at the trans bleeder. You dont bleed this clutch like brakes pumping up several times. Have someone push clutch to the floor and hold it there, then you open and close bleeder while keeping pedal to the floor. Check the fluid level every time you open/close the bleeder as this system is so small and will empty quick.

in a car this 'new' prob. hydraulic. check clutch fluid reservoir- should be near brake fluid res.- will be smaller- if fluid is low, or empty- may be clutch master cylinder, or clutch 'slave' cylinder is leaking. check for leak under car, should smell like 'brake' fluid. if your brake master- both reservoirs are to the full line, and there's fluid under car, close to where clutch master is located, or near front of , or side, of tranny- then it's a clutch problem of some kind (as if you didn't already know this!!) relatively new vehicle (by my standards!), should have hydraulic clutch.
do you mean- when you depress the clutch pedal, it goes to the floor, and you can't shift into any gear??
should have asked this first! front wheel drive or rear? i'll guess front wheel drive. may have hyd. fluid leak in master or slave. (apologize for 'terms', but as 'male & female connectors', it's traditional, non-racist and non-sexist nomenclature!!) gotta' be careful, in the 21st century!! if there are, as i stated previously, 2 similar reservoirs, close to each other, then you prob. have hydraulic clutch. may need 'master' rebuilt, or replaced, or 'slave' replaced-it can be rebuilt, but prob not cost effective!
sorry to be 'long-winded/ texted', good luck!