Lift pump???

[Followthesmoke]

Hey guys I bought my truck roughly a month ago, 3 weeks prior to me getting the truck the previous owner had the lift pump replaced( have the receipt) now it's out again.. Got it at the mechanic I use and he says he can get ebough pressure to it to run sometimes and sometimes it won't.. Just thought I'd pick your guys brains to see if there could be another culprit to my truck eating lift pumps