The throwout bearing is probably bad and when you put a load on it by pushing the pedal it stops the noise of the failing bearing. You will need to replace it. You might as well replace the entire clutch with a clutch kit that has the throwout bearing, pilot bnearing, clutch disk and pressure plate. This will save you time and money in the long run as taking out the transmission takes so much time that the cost of a clutch kit is mot much compared to the labor of removing the transmission. It does not take much to replace the clutch at this point either and they are bound to fail as well soon with the milage you have on the car.