97 silhoutte gas gauge problem

i was looking at a 97 sil for my dad because he became disabled and needs more room for his wheel chair and stuff and the guy that had it took reall good care of it but he said the gas gauge will stick i was wondering if it had an access panel in the back or if i have to drop the tank to fix it and a little off topic if anyone can tell me anything about these vans reliability wise. i drove it rides nice really clean and lots of room. be great for him. thanks