12VDC wireless controller

I’m building an arduino controlled pump system to load a tractor pulled fertilizer tank. I’m needing a reliable single channel transmitter and receiver to shut down the pump once the tank is filled. The tank has a electronic float and the receiver just needs to switch dry contacts that I can plug into my arduino. I purchased a MirCR15 a while back for another application and I think it may work for this as well, but my question is will the tx and rx reliably pair back up when the tractor returns to the pump station for the next load?
Also keep in mind this system uses a hobby radio controller for swinging out the load-out boom. This radio operates at 2.4GHZ.

Yes, MirC should work fine for you. They will try to re-establish communications when they come back in range. Depending on the version you purchased, most MirC controllers operate at 900MHz. Some also operate at 2.4GHz, but interference is usually not a problem as they use a validated communications protocol.
Hope this helps.