View Full Version : What did I do wrong? pics

01-27-2009, 09:34 PM
I started a thread earlier on how to rebuild a Hypro d252 pump. I got all the parts from Rittenhouse, rebuilt it, then ran 40 gallons of Lesco Pre-M through it. All good. Then I mixed up 30 gallons of Barricade, Gallery and blue marking dye and all was fine but when I went to turn off the pump I noticed the oil was milky blue. Got home and took it apart and both diaphragms were ripped. Look at the pics. I used the regular diaphragm's not the teflon or other one.

01-27-2009, 10:00 PM
Looks like you had the washer upside down. There is a big washer under the nut, the holds down the diaphram. Make sure the wings of that washer go up, or away from the diaphram. Its a commen mistake.

01-27-2009, 10:01 PM

Did you install the metal cup backwards???

01-28-2009, 09:20 AM
Don't use the plain rubber diaphrgms--use the "Desmopan" thats the premium chemical resistant type. Above guys are correct, make sure the washers are installed so they don't cut into the diaphrgm, and make sure the diaphragms are not installed wrong. I think the writing goes on the inside (oil side). You should not have to force the bolts thru the diaphragm, they should go in easily.

ted putnam
01-28-2009, 09:49 AM
What a Bazitch! Hard(if not expensive) lesson. Don't know about the 252 but I "burp" my D30 of excess air before I seal it up completely. Like Riggle said the diaphragm should say "oil" on one side and "liquid" on the other. Make sure they're facing the right way as indicated and no sharp edges of anything against the diaphragms.