Hey Dale,These are the problems I have seen,If the struts are not leaking and the pump runs & has plenty of fluid make sure the " T " that splits the lines to each wheel is not clogged beleive me I have seen this before and it was the last thing I thought to check.If its clean the sileniod on pump is bad, the from resivour to pump sometimes leak.Also the nitrogen bongs go out.I think the main reason for conversions is sruts leaking and techs not knowing how to trouble shoot sytem I have never seen a bad pump.If the pump doesnt run check the 5 prong relay by the pump.