Fx 4 stage pump failure????

Hi Mexcomp, I use a FX 4-stage pump and have not had any trouble with it so far.It has not done what I would consider a lot of work yet so I can't comment on long term reliability.
The 4th stage is good if you find pumping really difficult,but be aware that with a slightly easy effort in pumping comes the tradeoff of much less air going into your gun or tank.If you can pump on the third stage and have a rest,as suggested to let the pump cool down,I would say use a 3 stage pump.
An extra stage only adds to the complexity of the pump,more parts,o-rings that will wear and fail eventually like all pumps.
Cheers Paul.