How to fix the leaking Tetra EX 800 plus filter

Описание: This filter is running for 4 years already. It has started to leak in its 4th year. I have fixed it twice using the vaseline in head of the filter. This is to show you step by step how to fix the leaking. Unfortunately after 3rd fixing it started to leak anyway on its next day.... but the leaking last just half day. Now (after 10 days) it is still running without leaking. But I just can not count on it anymore.... I bought new JBL e902 filter.