Flatline tank problem

[Derman2k]

I have a pretty old 68 3k flatline. Its due for hydro in August and i was just messing around in my back yard and the tank would make a creaking noise when it recharged... Anybody know what this is?

[willboy_2]

I also use an older flatline 3k, you may not know this( as i diddn't for awhile), but the older flatlines come with 2 stars even though they are not enscribed. As a last resort, use one of them.

[painball]

request a RA # and send it back. my 68/3000 flatline is at AGD right now