Sand Filter Without Laterals

[arlight1]

Hi everyone!

Have you ever seen a sand filter without laterals in its interior?
We own a fairly decent above-ground pool (can't remember exact size) and started noticing clumps of sand on the floor of the pool.
We turned to the internet and found out it could be a number of issue, most commonly blamed on the filter laterals and center pipe.

We own a 'Lomart Spectra 4 17"' Filter model. The model and part assembly can be found here: Link

As you can see from that model and assembly, this filter does not have any laterals. Well we took to disassembling it anyway. We removed the multi-valve thingy at the top that controls the direction flow of water. Upon removing that we see the center pipe. We removed all the sand from the filter and found that it is indeed cracked on the bottom part labeled as #2 in the diagrams. The problem is that we cannot remove the center hose at all. If you look in the diagram, there is part #20, a screw, which actually comes from the bottom from the outer shell into the center of the tank itself.

I took some images to better show this:
Gallery

You can see quite clearly the cracks at the bottom of the center pipe. That screw, however, just twists and twists, presumably due to the nut also twisting inside the center pipe. How is the nut able to be reached? How can we remove the center pipe to fix/replace it? Any ideas?
We've tried googling this extensively, but have not found a sand filter without laterals and someone facing this issue.
Thanks, and apologies for the long read.

 

[Richard320]

It looks to me like you only have two choices.

Cut the head off the bolt underneath so you can lift the guts out and work on it on a bench or break the plastic pieces enough to lock onto the spinning part with some visegrips. Either way a bunch of pieces will need replacing.

To cut the head off requires a hacksaw or a die grinder or a dremel tool. Do you know any mechanics or wannabe mechanics who might have air tools? That bolt head is but a minute's work with a die grinder and a cutoff wheel. He cuts, you dribble water on it to keep the heat from melting the plastic tank. The hacksaw method won't generate so much heat, but will take a while longer. An electric drill with a sharp bit might also work, if you can keep it centered and use a bit just a hair larger than the bolt diameter to drill through the head until it separates the threaded part from the now-hollow head.

 

[arlight1]

It looks to me like you only have two choices.

Cut the head off the bolt underneath so you can lift the guts out and work on it on a bench or break the plastic pieces enough to lock onto the spinning part with some visegrips. Either way a bunch of pieces will need replacing.

To cut the head off requires a hacksaw or a die grinder or a dremel tool. Do you know any mechanics or wannabe mechanics who might have air tools? That bolt head is but a minute's work with a die grinder and a cutoff wheel. He cuts, you dribble water on it to keep the heat from melting the plastic tank. The hacksaw method won't generate so much heat, but will take a while longer. An electric drill with a sharp bit might also work, if you can keep it centered and use a bit just a hair larger than the bolt diameter to drill through the head until it separates the threaded part from the now-hollow head.

Richard, thanks for the response.
Just curious, why would cutting/destroying the bolt head, or the center pipe be necessary? I guess if we knew how it was assembled in the first place, we could work backwards to properly dis-assemble it. Do they just use a really long ratchet extension that reaches down the length of the tube to hold the nut while the bolt is twisted?
We'd really like to go without breaking it because we've had this filter a couple years now, and would prefer attempting to fix it ourselves.

 

[Richard320]

Richard, thanks for the response.
Just curious, why would cutting/destroying the bolt head, or the center pipe be necessary? I guess if we knew how it was assembled in the first place, we could work backwards to properly dis-assemble it. Do they just use a really long ratchet extension that reaches down the length of the tube to hold the nut while the bolt is twisted?
We'd really like to go without breaking it because we've had this filter a couple years now, and would prefer attempting to fix it ourselves.

From what I saw in your pictures, some kind of threaded insert is down inside that long tube. If there is a hex nut that you can see, then a socket wrench and some long extensions would have that out in less time than it took me to just type this. To me, it looks like there's a piece that should be locked into that tube but it's spinning.