Michael,
From Gerald Farris' comment on removing the SCA filter coolant hoses:
"There will be two cut-off valves (looks like water a faucet handle), one for each hose. These valves will cut off the coolant flow to the filter to change the filter, however they should not be used to disable the filter when it is no longer needed with ELC (extended life coolant). The reason that you should not just cut off the valves is that the hoses will no longer flow coolant and fail even faster than before. These two hoses are the most common cooling system failure on a C12. So you should disconnect them and plug them at the engine, or reroute them to a less hostile environment and use high temperature hoses with a filter that does not contain an SCA (supplemental coolant additive)
Gerald"
If I remember correctly, one of the hoses terminates at the intake manifold and other at the block. Both on left side of engine as you are looking at it from rear of coach.. No need to remove hoses. Just cut them and seal ports into intake manifold and block.
Changing your pressure cap from stock 13 PSI to a 7 PSI will greatly extend life of plastic tank. C12s don't run too hot so reduced pressure cap won't be a problem. As to checking fluid level, consider adding a recovery tank. See pic. I got mine at Auto Zone for <$20. You should be able to run the existing overflow hose to the recovery tank and then add a hose for an overflow from the new tank. As long as you can see fluid in the recovery tank you know the surge tank is full.
Steve