Mfg. of toilet: R Morris, B.Burden ? Age: approx. 16 yr. Capacity: 4 GPF
After flushing, water comes to normal level in bowl. In approximately 5 to 10 minutes water is 2 to 2 1/2 inches lower than the original level and remains at this lower level until flushed again. Sometimes while sitting on the bowl a ghostly whistling sound comes from somewhere in the bowl or tank. What could be the cause of this problem. Thank you.