I DREAD having to clean my pool filter. I have a C900 Star Clear Plus. To get the lid off I unscrew the locking knob then have to use a rubber mallet to hit up under the lid lip to get it off. After I clean the filter and replace it I then have to screw the locking knob while constantly pushing down on the lid lip. To then finish it off I use the rubber mallet again, this time to hit the lid down. It takes a lot to do this. You can see the mallet marks on the lid in the pic. When watching videos of others removing their pool filter lid, the lids come off and go on very easily. Why is mine so difficult? To add to it, water is now coming out from the lid lip.
- Jun 22, 2014
- 47,979
- Pool Size
- 17888
- Surface
- Fiberglass
- Chlorine
- Salt Water Generator
- SWG Type
- CircuPool RJ-45 Plus
Welcome to the forum! 
Well, I have the C1200, and while it's a bit different, there are some similarities - like the knob for example. One thing I do 2-3 times per year is add some silicone lube to the threads at the top of the steel bar inside that the locking knob attaches to. I also make sure to apply some silicone lube to the large filter O-ring that is designed to seal the upper & lower half's. Now inside the upper lid of my filter top, there is a plastic inverted cone of sorts that accepts the rod when you put the top back on. That plastic (cone) insert comes out of my filter by pulling. Maybe yours does too. Then you can inspect the e-clip and other parts inside to see if anything is wrong, rusted, or worn out.
Here's a thread about my filter. Maybe some of the info will help you.
Hayward Cartridge Filter Locking Knob Repair
Well, I have the C1200, and while it's a bit different, there are some similarities - like the knob for example. One thing I do 2-3 times per year is add some silicone lube to the threads at the top of the steel bar inside that the locking knob attaches to. I also make sure to apply some silicone lube to the large filter O-ring that is designed to seal the upper & lower half's. Now inside the upper lid of my filter top, there is a plastic inverted cone of sorts that accepts the rod when you put the top back on. That plastic (cone) insert comes out of my filter by pulling. Maybe yours does too. Then you can inspect the e-clip and other parts inside to see if anything is wrong, rusted, or worn out.Here's a thread about my filter. Maybe some of the info will help you.
Hayward Cartridge Filter Locking Knob Repair