0278240 Diaphragm (Green)
Includes: Diaphragm spring, oval spacer, membrane, and nut; as shown in picture.
This "0278240 Green diaphragm" replaces the older "0288771 White diaphragm" and "0270201 Red diaphragm" .
Fits the Following Series Pumps:(but not limited to)
- All Wave Series Diaphragm Pumps, 404+, 425, 505, 525, 650, 655, 830, 831, 833, 834, 835, 836, 838, 1050, 1150
- Pro Gold: 841, 844, 848, 850
And more! Very common diaphragm for Wagner and SprayTech. Check your manual or send us a email if your pump is not listed on this page and you can not find a parts section for it on our site.
Known Pumps it will not fit are the old 404 Classic (the discontinued 404 Classic did not even use a diaphragm it used a poppet/spring deal), all the big older HP/ST series.
F.A.Q.: How do you tell if diaphragm is blown??
Answer: It can sometimes be very hard to tell by just looking at it. Sometimes you can see hairline cracks in the diaphragm, but most of the time you can not visually tell. Main tip we have is to NOT pull the head of the pump to check the diaphragm. Why? You can test it easily without pulling the head. And if you do pull the head off the pump, the diaphragm technically must be replaced regardless if it’s bad or not once the head is pulled. Reason being is the diaphragms are blank when new, with no groves. The head when tightened down via the four bolts actually presses/cuts the grooves into the diaphragm which in turn is what seals the head from the pump and keeps the hydraulic oil from spewing out. So in short, don’t pull the head unless you want to replace the diaphragm.
Q.: So how do you determine if the diaphragm is good without pulling the head?
A.: There are two ways to check,
1) Check for diaphragm movement via the pencil test see below:
==Begin copy paste from Wagner’s FAQ’s==
F.A.Q.: My unit is not priming.
Clean and lubricate inlet and outlet valves. Make sure the outlet spring and ball come out when cleaning and lubricating. If inlet or outlet valves show wear, replace them. Check the level of hydraulic fluid. Make sure that you are getting diaphragm movement-to do this, take the inlet valve out, turn the unit on to prime, pressure about half way and gently hold a pencil, the eraser side down to see if the pencil moves. If does not move, the diaphragm needs to be replaced.
==End copy paste==
2) Another sure fire way is by looking at the hydraulic oil. The hydraulic oil should appear almost clear, or at the most a honey type color. If you see any sort of "milky white" looking substance in the oil, that means paint and or water is getting past the diaphragm and into the hydraulic chamber. If so the diaphragm must be replaced; also you would want to clean the hydraulic chamber as well as possible to remove any contamination, and replace the hydraulic fluid.