Ed Sobles releaser issue

[maple flats]

I have a double horizontal Ed Sobles releaser, yesterday it started failing to dump. It seems as one chamber filled it only partially switched in one direction, not far enough to dump that side and start filling the other chamber. I could pull the pivot plate to the other side with resistance. As side 2 filled it switched back properly. Any ideas? I wonder if the rocker arm got something between the 2 nylon or PVC surfaces and allowed a venturi leak allowing icing into the tubing which after thawing passed moisture into the piston. This morning I'll take that apart, clean the surfaces, re-lube and assemble the rocker arm. Then I'll remove the vacuum cylindar and open it up to see if any water is in it, or if any seals have failed.
Anyone have other ideas? I do own a double vertical HBR releaser which has not been used in 5 years and I have a complete seal kit to rebuild it, but that is way too tall for what I have and I'd need to make a quick adjustment to the elevation of the incoming lines. The Sobles has 14" I think height to the incoming manifold ports, I think the HBR was 22" if I recall.
Anyone ever service a Sobles double horizontal?

[ryebrye]

I've never serviced a Sobles releaser, but the build is probably similar to other double verticals.

Is this indoors or outdoors? When was the last time you cleaned / greased the moving surfaces? Molykote 111 works well (and is food grade etc - most of the maple suppliers sell the big tubes for around $30)

Does the soble releaser have screws to tighten / loosen how tight it is around the pivot points?

[maple flats]

Thanks for the ideas, but I ended up putting a new vacuum piston on. The old one worked good on the retract stroke but poorly on the extend stroke. The new piston fixed it. This summer I will open the old piston, likely there is a seal that has failed.
To answer your question however, my releaser gets lubed and cleaned daily. I use the food grade grease suggested by the manufacturer, and the piston rod along with 2 rods that are attached to the floats get a drop of mineral oil, also as recommended by the manufacturer.
When I spoke with the manufacturer I was told that they would give me a loaner to finish the season if the piston failed to fix the problem, but it now is working as it should.

[MillbrookMaple]

I have a couple of these units and have had similar issues with them. Loosening the piston nut and then lubing the metal shaft along with rubber grommet with oil gets it working both directions again. Also a little food grade grease on the slider plate between the 2 chamber inputs helps as well. Then I switch it back and forth as i tighten the nut until the moves quickly each time I flip the chambers. There is a sweet spot of tightness on the piston nut where it works best. Too tight or too loose it binds as well. Since you replaced the piston that is a solution as well but future reference his pistons do have a tendency to get sticky on the push direction in my experience. They will always retract but get stuck in the middle on the push. They are a little like some old farm tractors, you have to stroke them just right to get them running well. ;)

[maple flats]

Thanks for the ideas, I will try that when I rebuild it, I lube the rod daily but never loosened the nut. Right now the new one is functioning perfectly, besides I like to have a spare so all was not a loss. In fact I have a spare for much of my equipment, just in case.
If I had gotten this suggestion I would have tried it before ordering a new piston but I still had ordering a replacement in my extensive To-Do list anyway.