I am about to replace my tires and move my wheel sensors from my 18's to 19's. Is there seals that I should replace?

Thanks!

 

The tire shop should have the tpms rebuild kits for less than $10 a piece

 

Just fyi, I had two sensors with slow leaks. When I tried to take the sensors off to rebuild them, the nut galvanically corroded to the stem, resulting in destroyed sensor each time. I don't know how prolific this situation is, but I had good luck rebuilding Acura/Honda sensor. OE Sensors are made by Schrader and there is a rebuild kit for them available, though I doubt the tire shop will charge only $10 for it.
New sensor is not super expensive and you can reprogram the sensors yourself, search for TPMS programming on this forum.

 

I had my rims refinj ished on my 2010 altima coupe with 70k miles and the tpms sensors were so corroded i had to replace them all. 2 or 3 fell apart when the shop tried to take them off.
So depending on how old they are you might consider orderung a new set for the new rims. Rockauto has them and you can get a set of 4 for $140.00

Then you just need to program the car with them