paramount jv3 cleaner heads

[minivolks]

Hello, I recently bought the metal tool to get out the jv3 floor cleaner heads. They where stuck pretty good. I cleaned every head and replaced. They all pop up nice. However, the don't turn. I notice that other heads are on but not supposed to be. I have maximum pressure going to the manifold. Which I also cleaned and appears to be ok. So, is there to much pressure going to heads, pushing them up to tight? Do you think I need a new gear drive to the manifold? It's 15 years old.