Pressure tank unusual diaphram

[George Emmanuel]

I’ve seen only 2 types of pressure tank diaphragms; metal plunger with cup washers on both sides of the diaphragm for the plunger’s threads to pass through, and plastic plunger with convex surface where it meets the diaphragm. The first design has a hole and the second doesn’t. But I’m rebuilding a tank original to a 1956 10hp and it has a diaphragm with cup washers riveted and a plastic button that is hollow on the bottom where it engages the cup washer.

I suppose I can drill the rivet out and use a machine screw in place of a rivet when installing a new diaphragm, with the screw head on top to clear the plunger. Anyone seen this design before? Suggestions? Keep in mind I’m typically a square tanker and I’m fixing this motor up for a grandson to use.

George

• This topic was modified 4 years, 3 months ago by George Emmanuel.
• This topic was modified 4 years, 3 months ago by George Emmanuel.

[frankr]

Hi George. Actually, there is a third type. The last one had a plastic button with different cup washers that were not riveted to the diaphragm. The type in your picture is superseded by a kit to update it to the most recent version. Sorry, I don’t have the part numbers.

[frankr]

Showing the latest version. The mentioned kit updates your pump to this one. Or you can just order the separate new version parts.

http://www.marineengine.com/parts/johnson-evinrude-parts.php?year=1958&hp=10&model=QD-19&manufacturer=Johnson&section=Fuel+Tank

[ede]

George, Kit p/n is 377327. I do have several.
Ed

[George Emmanuel]

Thanks everyone! Ed, I’ll be in touch.

George

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