Same here Izero. Mines is hard to see. Here is a trick I did on accident. I poured a little to much then it came out the over flow spout. Once it did that I took a flashlight and looked at it. It was full. Try wiping the bottle off with some kind of cleaner. I used so WD-40.

 

WD-40 is a good degreaser... luckily I never had the clouding/staining issue yet with the overflow...

 

dude just take a flash light to the back of it and shake it a lil so you can see the fluid....

and thanks karr i wont take it all the way out

 

Any time N3ON. Yeah since I had that leak my uncle was telling me and my cousin dont try to take the plug all the way off or I would have a bigger problem than just a broken clamp. Here I thought it was my hose. See a shop would of sold me a hose (and just wiped mines off) and really all they did was change a clamp.