The clutch master cylindar is most likely leaking. It's literally a hydraulic piston attached to the clutch pedal. It is also possible that brake fluid is leaking from the brake master cylendar and running down the line to the clutch pedal, ending up inside.
If it is leaking inside the car, the heater core has failed.If it is leaking inside the car, the heater core has failed.
It could be that you have a leaking heater core, which resides inside your car. Another give-away for a leaking core would be a sweet smell inside the car and/or a sticky residue on the inside of your windshield.
the heater core, heater core hoses or heater control valve is leaking
It is either leaking down the inside of your firewall under the dash (master cylinder) or leaking just enough inside the trasnmission bell housing to not puddle and be thrown around by the clutch spinning (slave cylinder).
look above the clutch pedal on the inside of the car.
the heater core is leaking
There is acid on the inside and it has burnt through the metal that is keeping it inside. The reason the acid might be leaking out is because the battery has a leak.
You can't have it both ways. If it's using fluid, then it is leaking out. If you are not seeing any on the ground or at the slave cylinder have you considered that it may be leaking from the back of the master cylinder and running inside of the car. You may not have noticed because it is going between the firewall and the carpet.
had new blower motor installed in my 2006 gmc now waater is leaking inside car when ac is on
Leaking heater core
YES. Good possibility if it is leaking at the passenger side