shurflo vacum

[wlatrout]

I've been running shurflo pumps for the last 6 yrs. Originally was getting 24 -25 in. of vacuum at the pump now am doing good to get 15 in. of vacuum. I've walked the lines , fixed many squirrel chews, replaced the diaphragm and gauge on one pump and still get 15 in. Also use a recirculating line. Tried closing all valves , still doesn't max out. Also redid the manifolds this winter. Any ideas. As a side note I am covered in niter here in no. Ind.

[wlatrout]

Did some more line inspection. Found several tiny pin holes in places you would not normally find them. My woods wasn't tapped last year due to a hip replacement. Gave the squirrels a jump on m this year. Got the one line up 5 in. so I'll keep looking. I'm using 3/16 tubing. 7 lines 3 pumps.

[nhdog]

have you or did you check the manifolds for any leakage before setting them out ?

[bryankloos]

I"m running about 160 taps on a single 4048 and have 22"+ on each line except the two longest that show 16-18".
Check for leaks as I was able to pull 18-20" on 120 with a single 4008 last year.
I've found very small chews, slightly loose taps, manifold leaks, cracked taps, and a poorly tightened screen filter as causes for poor vac.
Assuming you are horizontal or better with pitch you should be able to pull 20 without any problem.

[mainebackswoodssyrup]

As Bryan noted above, it’s always a small leak somewhere. Several possibilities. Clogged filter and not sealed filter housing are very common if it’s not in the lines. We found a slightly warped filter cover today, we threw that out. That was a new one. When checking lines, look for fast moving air bubbles. We walk the lines and clamp one lateral at a time while someone watches the vacuum. That isolates the lateral then you can work up the line to find chews or a leaky tap.