A further bulkhead separated the fighting compartment from the engine and transmission bay. The engine compartment drew cooling air in through the top of each side and the roof and exhausted it to the rear. To allow fording through up to deep water, a flap could be moved to cover the lowermost air outlet. Air for the engine could be drawn from the fighting compartment or the exterior; it was then passed through oil bath cleaners. It was modified so that the exhaust fumes were redirected so that they were not drawn into the fighting compartment, a problem found when tanks were drawn up together, preparing to advance.