take it  to an rv lp service shop or put a small amount in and then use
leak detect solution to check the fittings for the valves and all the
joints.  double check that the bleeder was  properly closed as well.
test first with the valve in the fully closed position.  then slowly
open the valve and see if any leakage appears around the valve as you
are opening it.
you may need a new valve but not  a new tank

jimt
On Friday, Oct 4, 2002, at 16:57 America/Denver, Gordy Jones wrote:

> I'm not sure but I suspect that there is a leak or something in my
> propane tank. Before I bought it, the owner had not used it and so he
> was not sure if it worked. I asked if he could put some propane in it
> to test it and so he did that and it seemed to work. When I bought it
> about 2 weeks later, I fired it up for fun just to see for sure how
> well the stove worked, both burners lit just fine but after turning it
> off, i smelled a little propane outside the van. So, the next time i
> went to use it, i turned the valve outside, and then lit the flame,
> and it lit but then it died instantly. this happened each time i
> tried. So at this point i figure it is either out and needs to be
> filled up or there is a leak. What is the best way to find out for
> sure if there is a leak? and if there is one, do I need a whole new
> tank?