Hardi Diaphragm Pump Broken Valve Cover

[AUMF]

Hello,

We have a trailed Hardi sprayer with a 6 diaphragm pump (looks like a Hardi 363).

Recently it was leaking from where one valve cover bolts to the pump. It was a broken diaphragm. Replaced it OK but went again and now the bolt holding the diaphragm has broken through the cast valve cover.

What is causing it to break the diaphragms on one valve only and punch through the cover?

Cheers.

 

[quattro]

Hello,

We have a trailed Hardi sprayer with a 6 diaphragm pump (looks like a Hardi 363).

Recently it was leaking from where one valve cover bolts to the pump. It was a broken diaphragm. Replaced it OK but went again and now the bolt holding the diaphragm has broken through the cast valve cover.

What is causing it to break the diaphragms on one valve only and punch through the cover?

Cheers.

Presume there’s play in the con rod or crank
i probably have second hand parts if you can’t find any near you