Stonehaller
Platinum Member
Looking at just the parts diagrams for the B26 there is separate oil tank beneath the transmission on the B26. It appears that oil drains from the transmission housing through a flange into the tank. The filter housing is mounted on the side of the tank with an oil ring sealed fitting into the tank for pump suction supply. I suggest that you check that o ring as well as the o rings on the suction line from the filter housing to the pump. You should also verify the oil level in the tank to ensure the inlet through the side of the tank to the filter housing is flooded. Looks like there are a couple of breather hoses that go from the tank to the left side of the transmission. You may be able to remove one to verify the tank is full of oil after sitting. The parts diagram does not indicate if there are any check valves in the breather lines, but if pressure is getting trapped in the tank, it may be forcing oil back up into the transmission, lowering the tank level to where it allows air in the suction port on the side of the tank. Can't tell from the parts diagram whether the flange from the transmission sticks far enough into the tank for this to happen.