Pool filter problem

[jrc77]

I have a problem with my pool filter and am seeking any suggestions. As some background, the filter is underneath a concrete deck so access is difficult and restrictive.

The dome on top of the filter used to have a T piece with a pressure guage and a air bleeder on it - however the T piece was so corroded it snapped off when a piece of ply fell on it - leaving a nice water fountain out the hole at the top.

There are lines coming out of the centre of the dome from the hole - which I believe may be cracks but hard to tell from the angle I can see. Running my finger nail over the "cracks", they don't appear to be present on the outside of the dome.

I've attached two photos - one of the filter with the dome on top, and one with a close up of the hole in the top of the dome. The filter is a Niagara Mark II Series 600.

I have sourced a replacement "dome" however removing the existing one is proving problematic (I have a rope wrench that fits around the base of the dome and I have pulled with not insignificant force and can't get it to budge). Also tried whacking it with a hammer to see if I could smash it, but it didn't even scratch.

I have been told that removing the dome is extremely difficult on this model and that people in the past have had to chisel them off - however this runs the risk of damaging the screw thread and the O ring (underneath the dome).

One thought I had was to try to use something just to seal the hole - I don't use the pressure guage anyway (as it was so corroded and in such a difficult position). Any ideas? Would be under a bit of pressure so would need to be fairly strong.

Alternatively any suggestions for applying more force to remove the dome?

Regards,

Jason

 

[investor2009]

It looks like you would gain much leverage with the correct size (50 something mm??) socket, but considering they are generally expensive and specialised, maybe some long handled adjustable pliers will do the trick?

I have heard of cold chiselling with a hammer to remove things like this, but as with wheel nuts, you will damage the nut doing this and there really is no need for it if you just use pliers or a proper fit socket.