Originally Posted by Jimbo56
Youíre sucking air from somewhere. Between pump and tank. Maybe pump has a bad diaphragm? If you canít find a really loose fitting Iíd try a new pump.
I realized that the OP is now fixed, but for others that have a water pump issue in the future...
Water pump failure happened to me. And in my research I found that the rubber bladder inside tends to fail more than the motor.
You have two options (and I did both):
1) Order a new pump (wow...it makes a huge difference and you wonder why you put up a mediocre pump for so long). I ordered a matching Shurflo thru Amazon, shipped from RecPro. About $75
2) If you're mechanical, you can dis-assemble the old pump after it's been removed. If the motor checks out fine, then order a new bladder (about $25 thru Amazon), re-assemble, and now you have a spare water pump.
It's basically a bunch of stainless screws in a plastic housing. Very ez to figure out.
On edit: Oops, I paid too much. Now it's available for under $60
Amazon ShurFlo Water Pump - $58.90