TKE was using vegetable oil about 10 years ago and had all sorts of problems with leveling due to the fact that the veggie oil did not respond well to temperature change and also the jack seals did not react well to the oil either which caused a lot of friction causing poor ride quality. Every TK unit we had with the early vegetable oil we at some point ended up pumping out and using standard AW32 and changed the jack seals. There was strict instructions on the tanks that you were NOT to mix the veggie with any other oil.
Since then they started using a new biodegradable oil called Enviromax which I guess is a lot better.
My suggestion in your situation would be to get rid of the veggie oil and go the good old tried and true AW32.
