Hayward Cartridge Filter Locking Knob Repair Questions


New member
Mar 24, 2020
Sarasota Florida
Moved from here Hayward Cartridge Filter Locking Knob Repair

I'm having a hard time fixing this problem. I replaced the washer and the E Ring, but as I try to put the top cartridge together, the thing is not tightening all the way leaving water to leak at the middle seal. As I try to tighten it anymore, the locking knob won't budge and the seam bringing the 2 pieces of the cartridge uneven. I'm at my wits end with this as I have been on this for the past 2 days for hours trying to fix this. Please help
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Texas Splash

Mod Squad
TFP Expert
LifeTime Supporter
Welcome! :wave: I saw a similar thread a couple weeks ago. Those knobs on our C-1200 type lids can be frustrating. Bad enough getting that e-clip back in there. :hammer: In the other member's case, he discovered that after assembling the clip, cap, and everything else in there, he simply wasn't turning the knob hard enough to engage fully onto the center bolt/shaft. He was so used to the old parts fitting a bit more loose, he had to give it a bit more elbow grease to cinch-down onto that shaft.

So I would first ensure all the components under the lid to the knob are correctly assembled and tight, which I'm assuming they must be to get the e-clip back in there. Also make sure the center bolt/shaft is firmly screwed down into the base of the filter. You might also consider putting a little pool lube on the threads at the top of that center bolt/shaft. Once you have the top lid back on, aligned, and start turning the knob, make sure you are giving it enough turns to pull the top half all the way down firmly to the bottom section.

Hope that helps.