My sprinkler pump is about 25 years old. About 10 years ago I had it rebuilt. It worked fine until a few weeks ago. Some work was being done behind my house and I had to disconnect the pump for about a month and then extend the intake pipe (from a canal) about 25 feet in length. The run from canal to pump is about 10 feet vertical and about 120 feet long. Since I redid it (and replaced the check valve) it primes okay, but has very low pressure. Any thoughts on rebuilding this ancient pump vs. replacing it? Thanks!