Sprayer Depot Blog

Udor Kappa series pumps offer reliable, high-quality and popular solutions when working with harsh chemicals. Due to their anodized aluminum construction, they are ideal for handling a number of common of professional chemicals, such as herbicides, pesticides, liquid fertilizers, de-icing materials, and other hard-to-handle fluids. 

One of our top sellers is the Udor Kappa-43 diaphragm pump. This is a commonly used pump in various horticulture, agricultural, lawn care, nursery, pest control and turf spraying applications. Let's take a closer look at some of its best features!

Probably the most common issue we see with this type of pump is a diaphragm rupture. Fortunately, this is a pretty easy repair you can do yourself to save time and money. Continue reading below for steps on how to repair a Udor Kappa-43 Diaphragm pump and watch the easy instructional video that follows.

 For this project you will need the following tools:

• A screwdriver
• Wrench
• 1/2" socket
  
• 11/16" socket
• Diaphragm kit (3 piston diaphragms, 6 sets of O-rings)

Let's get started! Follow these steps:

1. Loosen the bolts on one of the 3 head assemblies
2. Remove the head assembly
3. Remove the diaphragm, nut, and washer
4. Remove the diaphragm
5. Remove the sleeve, and drain the internal oil
6. Loosen the bolts on the 2nd head assembly
7. Remove the head assembly
8. Remove the diaphragm, nut, and washer
9. Remove the diaphragm
10. Remove the diaphragm sleeve
11. Repeat this process on the remaining head
12. Clean the inside of the pump with carb or brake cleaner
13. Replace the sleeve, lining up the holes on the sleeve with the holes on the piston
14. The diaphragm has a beveled side; this side will be pointing out
15. Replace the diaphragm, nut, and washer; tighten with a wrench
16. On each side of the 3 outer head assemblies remove the inside of the valve cage, replace the spring, small seat (beveled side down), and large metal seat
17. Place the valve assembly back onto the head and replace the O-ring with a new one
18. The other side has the same pieces in the opposite order
19. Replace the spring, seat, and large seat
20. Replace the O-ring with a new one
21. Repeat this process on all 3 head assemblies
22. Replace the head assembly
23. Tighten the assembly skipping bolts in a clockwise pattern to evenly tighten
24. Replace the piston sleeve on the 2nd side
25. Replace the diaphragm with the beveled side out
26. Replace the diaphragm, washer, and nut; tighten with a wrench
27. Replace the 2nd head assembly, tightening the bolts with a wrench
28. Using non-detergent 40W pump oil; fill the open side of the pump to the brim
29. Replace the final piston sleeve, lining up the holes with the piston
30. Clean off excess oil  Replace the final diaphragm
31. Replace the diaphragm, washer, and nut; tighten with a wrench
32. Replace the final head

Do you have an instructional video you'd like to see featured? Let us know in the comments below.