The low level of the liquid may cause many malfunctions because air gets into the liquid, and the liquid slurry with the air becomes compressed, leading to erratic changes in pressure and malfunction clutches and band brakes. Also elevated levels of liquid leads to that rotating gear transmission whipped foam which leads to the same results as the air trapped in the transmission fluid. In any case, air bubbles lead to overheating and oxidation of transmission fluid, which is getting into the valve, disrupts the clutch and brakes. Foaming may leak fluid, which can be taken for leaking fluid. | 
