That kind of question is hard to answer without knowing more about where the exact problem is. If it is one of the flex lines they are easy to replace and not expensive. If it is a hard line that runs all the way under the car it could mean several hours of work, and could be fairly expensive.
How do you change the thermostat in 1999 Mercury Villager
Yes.
According to the 1999 Mercury Villager Owner Guide : ( 20.0 US. gallons )
In the engine.
No, no room.
134-A
4.5 quart
ABS was an option. Not all have it.
In the fuel tank.
There are two.
on my 1999 ford mercury villager its on top of transmission under the van
1999-2002 Villager or Nissan Quest.