Other day my pump slowed right down even with controller up full, i had to pinch hose to build up any decent water pressure to rinse window properly, my pumps over 5 years old and i thought it had seen its day possibly, but first i went to the controller and wired pump up directly....exactly the same outcome, checked all the hoses they were all fine.
Gutted i thought new pump needed. Then last thought check the little pre filter before shurflo pump and it was rammed! Lol, my own fault for not checking it more regularly. Just goes to show the importance of having a pre filter. And also to check them. Its like a new pump again now and i feel like a new man