Replace torn diaphragms on the Hypro D1064 or D1064GRGI Diaphragm Pump with the parts included in this Hypro 9910-KIT2480 Diaphragm Repair Kit. You will know when its time to replace the diaphragms if you see there is a milky grey color in the sight glass of the pump. This most likely indicates one or more of them are torn. Do not run the pump and replace the diaphragms or else extensive damage to the pump may occur. If your pump is in constant use, you should be replacing the diaphragms every 3 months or 500 hours. Hypro 9910-KIT2480 Repair Kit includes 4 x Desmopan Diaphragms (# 9910-1040080), 1 x Pulsation Diaphragm (# 9910-1800300), 8 x O-Rings (# 9910-770571).