Is a 2000 Dodge Grand Caravan fuel filler neck usable in a 1999?

1)Block front wheels.
2)Jack up the left rear tire off of the ground.
3)Put blocks up under the frame.
4)Take off the left rear tire.
5)Take out the plastic liner in the fender well that covers the fuel filler neck.
6)Loosen up the hose clamps on the rubber fuel filler hoses. (at the neck side); once the clamps are off plan on buying new ones. This next part of the job is VERY IMPORTANT! use a flat screwdriver and pry 360 degrees all around the rubber filler neck hoses. (they get kinda glued on from being on there so long). Next Get some PB Blaster lube or WD-40 (it has to have the small red squirt hose) and spray the lube up in between the hoses while you pry around. the more you do this the easyer it will be to pull the metal filler neck pipe out.
7)Now its time to take out the 4 bolts that hold the pipe on.
Use a 10mm socket and extension to take out 4 bolts up top behind the fuel filler door.
8)Pull the filler neck out and put everything back together the way it came apart and your done!

yes depending on where and how broken some hose and a few clamps should correct the problem

2001 Dodge Grand Caravan filler neck hoses Bing images

its all 1 unit,
http://www.autopartswarehouse.com/shop_years/dodge-caravan-fuel-filler-neck-2001.html

2001 2002 Dodge Caravan Grand Caravan Voyager Fuel Tank Filler Neck...

Replace the Gas Cap.

disconnect all fuel lines, vacuum lines, electrical connections at the fuel tank. disconnect the fuel filler tube, then support the fuel tank as it will be heavy, unbolt the fuel tank straps and lower the fuel tank. clean the top of the tank so no dirt falls into the tank. undo the tank unit lock ring and remove the tank unit(fuel pump assembly).

Anti siphoning device. Is fitted to most cars and vans now one way is to obtain. An electric fuel pump and disconnect fuel line at engine connect the electrical fuel pump externally to car anp pump out fuel into container

the filler neck rusted out or is it leaking after the van running then the gas lines are rusted out

OPEN GAS CAP FLAP THEN YOU NEED TO DRAIN GAS BELOW FILLER NECK.THEN LOOSEN REMOVE SCREWS IN THE GAS CAP FLAP AREA WHERE FILLER TUBE CONNECTS THEN GO UNDERNEATH VAN LOOSEN REMOVE HOSE CLAMPS AND REMOVE THE HOSE AT THE FILLER NECK BELOW THE GAS TANK.SPRAY WD40 AROUND HOSE AREA AT METAL FILLER TUBE STICK OUT GAS TANK.CAREFULLY USE LARGE PAIR OF CHANNEL LOCK PLIERS TO REMOVE WORK HOSE OFF METAL TUBE FROM GAS TANK. IF YOU CANT REMOVE HOSE WITH HANDS.BECAREFUL NOT TO MAKE ANY SPARKS.PLACE RAGS AROUND ANY METAL PARTS TO KEEP CHANNEL LOCKS FROM HITTING METAL MAKING SPARKS.

If you're on the smallish side and pretty limber, you might avoid removing the rear wheel. If not, you will likely need to remove the rear wheel and put the van on jack stands securely. I would remove the underside splash shield and gain access from underneath. It looks like you will need to unscrew the plastic insert that surrounds the filler neck inside the area that is exposed when you open the fuel door. Make sure you get the vent hooked up correctly when you are done.