If you are using a save file that was started before installing the Hydraulics mod do the following.
Uninstall the Hydraulics mod.
Start the game and from inside the game delete every car from your garage (just to be safe).
End the game
Reinstall the Hydraulics mod (and the cheat mod as well).
Restart the Game and from inside the game use the cheat codes to give yourself the vehicles you had to delete.
The reason is the way cars are stored in the save file.
Cars without the hydraulics option in your game save (IE vehicles in your garage) will crash the game if you do not remove them.
You can run the game with the broken cars in the garage, but as soon as you call on that car to be deployed (hud menu vehicle delivery, or going inside the garage at either a Rim jobs or a gateway) the game will lock up.