I have a 1997 Rav4 with a standard transmission. In the last couple of weeks the clutch has started to slip. I am wondering if there is a clutch fluid resevouire that may need topping up? I have looked all over the engine compartment but have not been able to locate one? The slipping only occurs when the engine is over 2000rpm, could this be anything other then the clutch assembly? Could it be the slave cylinder? Or anything else?