Hypro 9910-KIT1723 Diaphragm Repair Kit for the Hypro D252 and D252GRGI Diaphragm Pumps. The repair kit includes 2 x Desmopan Diaphragms - Clear (# 9910-800085), 1 x Accumulator Diaphragm (# 9910-800190), 2 x Head O-Rings (# 9910-480440 ), 2 x Head O-Rings (# 9910-800210). If you see the oil in the sight glass has a milky grey color or if oil comes out the discharge port, this usually indicates one or more of the diaphragms have torn and need to be replaced. Diaphragms should typically be replaced every 3 months or 500 hours if your pump is in constant use.