Sprayer Depot Blog

Follow These Step-by-Step Instructions to

Complete a Diaphragm Repair on a Hypro D30 Pump

Using an 11/16 inch socket remove both bolts on either side of the head. After removing the top head assembly, remove each of the 4 bolts on the head to access the diaphragm.

• Remove the diaphragm bolt.

• Remove the old diaphragm.

• Remove the piston sleeve and drain the oil.

• Remove the 4 bolts on the opposing side to reveal the second diaphragm.

• Remove the diaphragm bolts and diaphragm.

• Remove the second piston sleeve. 

Now that both piston sleeves are removed, clean the pump with carb or brake cleaner to remove excess water and oil.

The D30 Diaphragm Kit consists of 2 diaphragms, your air accumulator diaphragm, and 4 O-rings for the valves. The piston sleeve has 2 holes at 12 and 6, insert the sleeve over the piston.

Once the piston sleeve is in place, put in the new diaphragm, be sure the proper side faces the oil as marked on the diaphragm.

• Replace the washer and diaphragm nut with a ¾ inch socket.

• Replace the head and tighten with a ¾ inch socket.

• Add non-detergent pump oil into the other side of the unit, fill almost to the brim.

• Replace the second sleeve with holes at 6 and 12.

• Clean excess oil, replace the diaphragm, washer, and nut.

• Install the 2^nd side of the head, sealing the oil inside.

• Now that both sides are on tight, place the 2 new O-rings on the base, the other 2 on the head assembly.

• Using your index finger and middle fingers, hold the O-rings on the head and place it over the base.

• Tighten the 2 bolts on either side of the head assembly.

 Now we’re onto the air accumulator diaphragm: 

• Remove the bolts with a ½ inch socket.

• Remove the old accumulator diaphragm, placing the new diaphragm flush in its place.

• Replace the top and tighten the bolts down.

This concludes the Diaphragm Repair Kit Install.  You can also watch our Instructional Video on this topic: