Why is there liquid in my macaroni salad, potato salad and tuna salad the day after making them?
Have you tried baking pasta, after boiling it in the water? 

I highly recommend you bake the pasta in the oven on very low heat, for 20 minutes, then you will see that there is no more liquid. 

Also it gives the macaroni a spongy condition which makes it able to keep the liquid in it. 

I believe if you bake the pasta before mixing with mayonnaise, you will get a good result.