The other day I had tree sap on my car from a valet. Tried to spray the squirters on the window. The First 2 tries were very sporadic, sprayed mostly on the driver's side, a lot on the glass roof. 3-4th try only the driver's side worked, very weak spray. 5-6th no fluid at all. This was the first time ever using it, I assume the tank would have more capacity than 3 or 4 sprays. Is this normal?