You can take your vacuum cans apart??
If so they are not OEM, and if they are not OEM they probably leak at the boot that seals on the shaft. People have various solutions. I'll be installing old OEM shaft/boot seals on my re-pop cans when I get them.
On the OEM units the diaphragm almost never fails, it's the shaft boot that gets rust under it where it seals to the can that makes them leak.
Oh... nevermind ... I see that is a pan with rusty water ... I thought it was half of the vacuum can
