Replace the Diaphragm on a KAPPA-40 Diaphragm Pump

Spray Equipment Repair DIY How To Repair Video

Many of the repairs on spray equipment are fairly quick and easy to do yourself, saving you time and money. Replacing the diaphragm on a KAPPA-40 is no exception. The diaphragms are essential to optimally working diaphragm pumps, and they do wear out quickly with heavy use. Keeping these in good working order will ensure you are getting the most from your investment and help avoid costly breakdowns and downtime. 

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KAPPA-40 Diaphragm Repair Video and Step-by-Step Directions

 Tools:

• A screwdriver
• Wrench
• 1/2" socket
  
• 11/16" socket
• Diaphragm kit (2 diaphragms, 2 sets of O-rings and an air accumulator diaphragm)

Steps:

1. Loosen the bolts in one of the two head assemblies to remove it
2. Remove the diaphragm nut and washer using the wrench
3. Remove the diaphragm
4. Remove the piston sleeve
5. Drain the internal oil
6. Loosen the bolts on the second head to remove it
7. Perform steps 2-5 for the second head 
8. Clean both sides of the pump with break cleaner
9. Place the piston sleeve back in place in one of the two heads
10. Place the diaphragm inside. The diaphragm has a beveled side which needs to be facing up
11. Use the wrench to tighten the nut and washer back into place
12. On each of the two head assemblies remove the inside valve assemble
13. Replace the spring, valve seat (beveled side down), and large metal seat
14. Replace O-ring with a new one
15. The other valve assembly has the exact same parts but reversed (follow steps 13-14)
16. Switch to the other head and perform steps 13-15 for this side as well
17. Place the head assembly back in place on the side where you replaced the piston sleeve (step 9)
18. Tighten bolts in a clockwise pattern to tighten evenly
19. Switch to the other head and use non-detergent 40 weight pump oil to fill that open side
20. Place piston sleeve back in place
21. Clean up any excess oil
22. Replace diaphragm, making sure that beveled side is facing up just like in step 13
23. Use the wrench to tighten the nut and washer
24. Place the head assembly back in place and tighten screws in clockwise pattern to tighten evenly   
25. There is a clear bolt on the side of the pump and the oil level should be visible right in the center
26. Remove the air accumulator head by loosening the bolts
27. Once opened, remove the air accumulator diaphragm and replace with new
28. Close everything back and tighten for a secure fitting

You are all done! Our customer service reps are available during normal business hours Monday through Friday. They are happy to help if you have questions about spray equipment or repairs, or need help locating replacement parts and kits.

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