My question involves personal property located in the State of: PA
My sister and her ex-boyfriend purchased a truck together. The truck was traded in with her truck and also one of his trucks. The new truck is registered to both of them. However, he took out a home equity loan (for better interest rates) to pay for both the new truck and also a trailer he purchased. He is paying the insurance on the truck along with the loan for the remaining balance. My sister had been the primary driver of this new truck. They have broken up and my sister is still driving the truck. What rights does he have to take this truck back? Can he sue her for half of the truck or is possession truly 9/10 of the law? and what rights does she have to fight him to keep it? She has offered to take over payments to the bank and also take the trailer since the original home equity loan was for the truck and trailer together. He has asked her for $$ equal to 1/2 of the balance remaining on the truck or offered to pay her the $$ equal to her original trade-in.
Any advice would be greatly appreciated. The last thing we want is for her to get sued or the police to show up.

