Pump difficult to prime-surges-will not pick-up??

You don't give the year and model, and I'm sure its not a Cutlass Ciera if it has a 231.
Usually its a good idea to pack the gears with grease or vaseline to help prime the pump. Since the pump is mounted on the outside of the engine it can be very difficult to get oil from the sump into the pump gears for the first time.

it sounds like you may have a suction side leak on the pump. check the lid o-ring and the suction side fittings to see if there may be a possibility of air being sucked into the pump and causing it to act like it's picking up prime and then losing it.

To replace the switch, shut off power, remove wires noting all wire locations.
You may have to relieve pressure in the system by using water until the surge tank is empty.
I'm not sure about that.
You do have to either remove the switch from the piping by unscrewing it or remove the piping from the switch by removing the connector and unscrewing the connector from the switch.
Assembly is the reverse. You should use teflon tape of dope on the screw connection below the switch.
The procedure should take about a half hour but you won't have any water during this time.
Gary

i think its pump side first as its easier to push water through a filter rarther than trying to **** it , Also the only reason it could loose its prime is through air getting in the system.

old pump. they've been updated!

I have a sta-rite mkse-6 pump and it has lost its prime..... how do I prime it???

It is self Priming. If it will not Pick up, You probably need to Replace the Fuel Pump.

Prime is the term we use to state that the air has been mostly purged from the pump and the pump is moving water. When you have lost the prime, your pump is no longer pumping water through it. Sometimes it can be very difficult to regain the prime on the pump. This will tell you how to get the prime back in these difficult situations