seal groove of the ZAKO ring and place the O-ring carefully into the groove, making sure it is not twisted. 4.2 Lubricate the threads of the screws. (e.g. using mineral-oil based hydraulic fluid HLP32). ZAKO [...] seal groove of the ZAKO ring and place the O-ring carefully into the groove, making sure it is not twisted. 5.2 Lubricate the threads of the screws (e.g. using mineral-oil based hydraulic fluid HLP32). 5 [...] the condition of the O-ring and then put it back into the groove carefully, making sure it is not twisted. ZAKO flanges are easy to re-assemble. Follow all the final assembly instruction steps when re-assembling