[lynchmob]

what he said.

Originally Posted by lostmarbles

Let me answer that for Lynchmob if I may.

The diaphragm comes "prelubed with neatsfoot oil" and is nice and soft. So there's no need to apply anything during installation. (Just keep engine oil and dirt off it as you install it.)

It is actually sold in a sealed bag with the neatsfoot as this photo shows:

Attachment 232076

To keep it nice and soft after it has been installed - Just add a couple of drips of neatsfoot through that "application hole" in the top of the diaphragm housing every time you change the engine oil.