Plastic Dome on S200 stuck - How can I loosen it?

[MJCP]

I have a Hayward S-200 Sand Filter
The Dome Top has an O'Ring Seal which is leaking I assume the previous owners (new house) Overtightened it to try to stop the leak
I plan to Clean or Replace the Oring and relubricate.

I bought the Wrench made for removing this part, But it is Stuck and the wrench doesn't have enough torque (Short Handle) to loosen it. I have considered buying a Pipe to extend the handle thus providing more torque, but the wrench is Plastic and would probably break. Or worst case the dome threads might break.

Can I spray WD-40 on this to loosen the plastic to Plastic threads?
Or do you know a better way to remove this without risking breaking the Dome or the Wrench.

[Guest]

I think i have the same problem. I called the pool guy up and he just replaced the clamp. I opened the clamp and cleaned my cartridges, Then, i tried to close the filter again and now it won't close. The clamp doesn't fit around the filter head. I tired lubricating the o-ring to make the filter head fit but it didn't work. Can someone help me out wit this or tell me what is wrong?

[Guest]

i have that same prolble m right now

[Guest]

Make sure the air bleed valve is open so there is no positive or negative pressure in the filter.

You can try short, sharp taps with a piece of 2x4 or some other material that won't break the plastic wrench easily. The important thing is the initial budge. After the first movement it becomes relatively easy to turn the top off by hand (using the wrench).

When hitting the wrench it is best if 2 people can do it. One to make sure the wrench remains properly seated and the second to 'hammer'.

[Sutckpool filter]

I just used a hammer and a washcloth doubled up and tapped the wrench over and over until it came loose. Painstaking process but it is the only thing that worked. I did try lubricant spray too.