Occasionally trouble is encountered due to oil from the tank draining through into the crankcase when the engine is stationary. This is usually due to the check valve failing to close properly. The remedy is to remove the timing cover and re-seat the ball valve. The valve consists of a ¼" diam. steel ball, part No. K100, held on to a seating in the main oil pipe by a check valve spring part No. RT115. The spring is held by a check valve plate M225, which is lightly tapped into the main oil passage 1/8" lower than the timing cover face. The plate and spring can be pulled out quite easily with a pair of round nosed pliers.
To re-seat the ball, insert a punch into the oil passage and tap the ball once or twice against its seating. Afterwards make sure that the spring is in good condition and refit this and the spring plate. IT IS IMPORTANT not to tap the plate in too far as this might prevent the ball rising when the engine commences working and would restrict the flow of oil to the engine. The main oil passage in which the ball valve is situated is quite noticeable as soon as the timing cover is removed, and it is the large hole which registers with the oil passage cast in the face of the timing cover