Question
4 yr old pump, bladder tank, app 125ft, serves as whole house. overheated last week, blew pvc fitting. (top of pump to pipe of bladder tank. replaced fitting, checked all others for leaks. ran fine for day and a half. blew again last night. motor casing extremly hot, fitting soft & balloned. still pumps water. what the hey? thanks for any help u can give.

Answer
Thanks for the question.
Two things can be causing the problem. Either the suction side of the pump is drawing a little air. Or your pressure switch is not shutting off the pump correctly.
The pressure switch can work intermittently so I would change it while you're doing the other repairs. They are less than $20. As for the suction, you'll need to check and recheck it for any air leaks. Something to try is, apply pressure to it, air or water. Then apply soapy water to all the joint and watch for bubbles.
If you need more help reply back.

Matt