Shurflo 4008

[bryankloos]

Hello All,

I'm on my 3rd season with the Shurflo 4008, and noticed that I never really pulled a solid vacuum. Even on my best runs with the recirc open I average 15-20" vac. other than the obvious leaks in the manifold or elsewhere, is it possible the the pump itself is decreasing in its ability to pull vac? Are there any methods to check/service these pumps?

Thanks!

Bryan

[DRoseum]

Mfg says they can pull liquid up 6 or 7 ft to self prime. Fill a bucket, set it 6 feet below your pump, run a single tube down to it and give it a test.

When manifold is closed off and only full of air, I have seem them pull maybe ~8 inHG. I didn't let it run long like that and maybe it would climb higher, but you could use that as a benchmark as well.

For what it's worth, it could just be the season. Lots of air in lines, too warm and reduced sap flows etc. My shurflo seemed to be in a similar range to yours for the entire back half of the season after those 4 consecutive warm weeks going over 70F here. Earlier it was pulling 28 inches.

Lastly, you can easily disassemble the pump and clean/inspect the pump head/diaphragm. They are easy to take apart and reassemble.

[RC Maple]

It's my second year with a 4008 pump. I thought my manifold build was good last year but my pressure test in a water bath showed I needed to improve my connections. Testing the manifold before this season, I got up to 25.5 in vacuum. The best performance I saw during a run this year was 24.5". Most of the time I am getting about 21. I thought I would really get after this and find every leak, so I got an Inficon leak detector off of Ebay. In my pump box, the detector seemed to give the loudest indication of a leak on the back side of the pump itself. If that's the case, I may have to further check that out after the season is over.