Any statute of limitations on divorce agreements? [CA]

tl;dr: Parents divorced in the 80s. Divorce agreement said my brother and I are supposed to own a property when I turn 23. That was 9 years ago. My brother is crappy and I don't want to own the property with him, but don't want to sell or let him have it (nor could be possibly buy me out). Is there some statute of limitations on divorce agreements where after a certain amount of time they are not enforceable? Alternatively, how can I stop that agreement from being a threat to trying to make the financial picture more healthy at the property?Back in the 1980s my parents divorced. They owned a small house outside of Oakland that they wanted to keep (It's in a nice location), but in the divorce they said it should be held in trust until I turn 23, then ownership should be transferred to myself and my older brother. I turned 23 almost a decade ago and that part of the divorce was not followed. The property became sole ownership of my mother after the divorce and was run as her personal property up until today.Personally, I do not care that this happened and I am not looking for a way to "punish" them or get money that I am "owed". The rental property kept us afloat, housed, and supported both myself and my brother through a variety of hard times. Both parents are flawed people trying to do their best. My brother on the other hand, has turned out to be a bit of a shit. He hasn't had a job in nearly two decades. When our father broke fell and hit his head/broke his hip and needed help, he didn't show. I don't want to know what schemes he uses to get his money and I don't want any part of whatever it is.My problem is that about once a year or every other year, he pops up talking how he wants "his share" of the rent from the property and how dad is a horrible property manager. It's rented way under market and now that dad is retired, I've crunched the numbers and not having that rental income means his financial picture darkens quite a bit. I plan to raise rents modestly, but his demands don't reflect the math of the situation and ignore things like taxes, insurance, and maintenance costs. If we were to set things up right with rent going into a reserve and paying for everything directly, his 50/50 share of the profits would end up as $50-100 a month - which is far less than he thinks he is owed.I'd like to get him out of my life, but this property poses a problem. If we become joint owners, I will be miserable and the last thing I want is to be dependent on his decision making (which has been an unmitigated chain of bad choices). I don't want to cut him a check. I don't want some stupid ass claim he incurs coming at the property because it's his "asset". I don't want to have to debate him on management choices. I don't want to interact with him or have a reason for him to come around. I do not want the divorce agreement to occur. Is there some type of statute of limitations on this type of thing? I also don't want to give it to him or sell it. I would like to restructure the property so that things are more orderly and so money has a clearer delineation, but I don't want that to be an opening for him to get the divorce agreement enacted and take actual ownership of it. Without a path forward, I'd rather just let my father keep it until death so my brother doesn't sap my father of his money. What do?