Old friend has a truck parked in my driveway . He said he would come get it and has not. I want storage fees before he can take it. Is that legal?

You can only collect storage fees if your friend AGREED to pay you storage fees.  Just because you want him to pay storage fees and told him that you want him to pay storage fees does not create an obligation on his part to pay you storage fees unless he agreed to them.You might be able to argue that he has abandoned the vehicle.  In Texas, you can apply for a certificate of authority to remove an abandoned vehicle from your own property.  https://www.txdmv.gov/motorists/buying-or-selling-a-vehicle/abandoned-vehiclesOnce you apply, the DMV will give notice to the registered owner to remove the vehicle.  If the owner fails to do so, the DMV will issue you a certificate of authority which will allow you to have the vehicle removed from your property.This may not be a perfect solution, however, as he has told you (apparently multiple times) that he will remove his truck from your property.  So he has an argument that you have actual knowledge that he has not abandoned the vehicle.  And he has an argument that you agreed to allow him to park his truck in your driveway, which creates what is called a "bailment" in law.  As the bailee, you are strictly liable to redeliver the property to the true owner.  So, if you choose to apply for a certificate of authority to tow the truck off your property, I strongly recommend that you deliver it to your friend's property to avoid being liable for misdelivering the truck.