I had a pump that developed a leaky diaphragm valve body / seal - allowing water & deposits to make their way into the bearings - eventually the deposits locked the pump up.
if you're NOT running a strainer on the pump you should be (it'll help keep deposits out of the pump),
the strainers can be cleaned or you can replace the screen...the entire strainer (pictured below) is less than 15 bucks
you can rebuild the most of these pumps (cheaper than replacing 'em, usually). I had to replace the drive assembly (bearings) which were about 60 bucks and since i was there i replaced the diaphragm too which set me about another 40....expensive sure, but a lot cheaper than 250 bucks for a new pump.
if you know the pump model number and specs you can search for parts - but ultimately you'll need to pull the pump apart to determine what parts you'll need.
Don R.
'04 42' Haulmark Motor Coach - 450hp/1650tq / 12 spd SmartShift
'12 Jeep Wrangler Sport (manual trans)
'17 Platinum F350 (6.7L, SRW, CC, Long bed, 4x4)