Hypro D403 Diaphragm Kit
Diaphragm kit 9910-Kit2423 comes with all the parts needed to rebuild the Hypro D303 and D403 pumps. Hypro recommends changing the diaphragms every 500 hours or three months, whichever comes first. If your oil has turned a milky color, chances are a diaphragms needs to be replaced.
This kit includes three replacement Desmopan diaphragms (9910-800085).
When replacing the diaphragms follow all factory torque specifications. When replacing diaphragms new pump oil will be required. Replace with 30 weight non-detergent or Hypro pump oil (2160-0038).
Other kits available for the D303/D403 are the valve kit (9910-Kit2388) and o-ring kit (9910-kit2389).