Depending on what type of car wash vacuum cleaner you have the number of filter bags can range from 2 to 4. It doesn't matter what type of vacuum you have, you still have to change your filter bags approximately once every year. To replace the filter bags on your car wash vacuum, open the access door
on the side of your unit and reach inside and release the spring loaded
clips. Then reach up on the top and unhook the bag and remove. Inspect
the bags once you have them out, If there are no rips, tears or wear in
them, simply machine wash them in a washing machine and replace. If the
bags show wear, you'll need to replace them.