I'm having a problem with the mineral oil leaking from the top cap of the reservoir. My question is: Is that top cap supposed to be sealed to the main twist off cap or does it pop off normally by twisting and pulling up? I'm trying to determin if I have to replace the whole reservoir cap or why that top cap keeps popping up a bit and the HSMO is leaking out. Any assist or tech drawings would be helpful.

Thanks!

Smitty