got a tune-up (they did not change the fuel filter) and serpentine belt replaced, serpentine belt broke due to incorrect replacement van over heated. Got the belt replaced again and now I have to add transmission fluid to my van every four days. What has caused this issue with my van that I never had before? Autozone checked my battery and alternator, everything worked great. The van will not move when placed in gear so I took it to a mechanic, who added transmission fluid, when my van does not move when put into gear, I check the fluid and need to add some four days laer from the last time added.