Filter Press Diaphragm Pump with No Suction

[SeanD]

I have this CDL filter press with a 1/2" diaphragm pump (https://bascommaple.com/collections/filter-presses/products/cdl-7-filter-press-with-4-frames-and-a-1-2-electric-diaphragm-pump) that has no suction. Even when I remove the hose, it will not pull against my hand.

I had a difficult time with it at the end of the day yesterday where it was pretty full and the pressure kept rising. I had a lot of niter. I got through about 14-15 gallons and I called it quits. I was able to flush it with no problems with hot water.

Any ideas where to begin?

[wiam]

First guess would be to take it apart and clean the valves. I sometimes have to do that with mine at the start of the season.

[SeanD]

Thanks for the input. I disconnected it on the outlet side. Some water from the previous flush dribbled out, but still no suction. I'll see if I can take the fittings off, but I'm worried it's the diaphragm now. The head of the pump is held on with what looks like torx screws. I have an email in to CDL to see what they say.

[SeanD]

Thanks for the input. I disconnected it on the outlet side. Some water from the previous flush dribbled out, but still no suction. I'll see if I can take the fittings off, but I'm worried it's the diaphragm now. The head of the pump is held on with what looks like torx screws. I have an email in to CDL to see what they say.

[SeanD]

All is well in Woodville! Big thanks to the folks at CDL and an email from lpakiz, a former Maple Trader who was visiting the site. Both had the same advice that worked like a charm.

Apparently sugar can gum up the diaphragm and check valves in the head of the pump that can cause the lack of suction. All it needed was a blast of hot water from a hose. After about 20 seconds, I tried the pump and could feel suction on my hand. I gave it a few more rounds of hot water then I filled a bucket of hot water and it was able to pull that up. I cycled that for about 5 minutes just to make sure there was nothing left in there. After that I packed 12 gallons.

No replacement pump, no rebuild, just hot water. Phew!

[Sunday Rock Maple]

First guess would be to take it apart and clean the valves. I sometimes have to do that with mine at the start of the season.


Mine was hardly pumping and I replaced the 5 micron air filter and it's working better but not up to what it was. I've never had the pump apart, but it looks like there are output valves on the top and input on the bottom. Is that correct? Also wondering if I need a gasket kit (don't have an owners manual)? Thanks for any advice!

[SeanD]

You may not have the same pump. I don't think this diaphragm pump has an air filter - at least nothing external. The hot water flush did the trick, though the next couple of times I used it the syrup was pulled up the inlet hose very slowly. Once it got to the pump, it primed itself and ran at full bore. I did more flushes with water and now it pulls from a bucket on the floor without issue. There must have been some sugar or gunk in the works that was washed out. I never ended up having to take it apart.

My Shurflo 5059, also a diaphragm pump is a different issue. I've broken it down and cleaned it out and it's still not pulling. That will be an off season project.

[Sunday Rock Maple]

Thanks for the reply. Mine doesn't have an air filter either -- it's at the bottom of the inline regulator and oiler feeding into the pump.