Vacuflush vacuum switch adjustment

[madhatter1]

My forward head would take a long time to pump down due to over pumping. I adjusted that switch but now not enough vacuum and it looses vacuum and cycles now and then. Did not do this with too much vacuum.

The guest head pumps to what seems to be correct vacuum but it has always lost vacuum (at bowl where lever goes through to operate flush ball) at a slow rate and would also cycle. Problem with this one is while it works perfect after a flush when it repumps it will not shut off.

So asking proper way to adjust and should I lubricate the spring mechanism with WD-40? Don’t want to do something I cannot undo.

 

[Pascal]

VF instructions explicitly say the switch and spring is not adjustable. Do not mess with it

How old is the switch? With time the membrane inside gets stiff and the switch starts acting up. Sometimes just touching it will trip It off. 10/12 years is about as long they last

None of the symptoms you describe (vacuum loss) have to do with the switch although I have no idea what you meant by “taking a long time to pump down due to over pumping”

How old are the duckbills? 5 to 7 years is as long as they will last. They may still work but will take a lot longer to build vacuum.

 

[madhatter1]

Over pumping as in major vacuum. Much more than needed. There is an adjustment that maybe I should not be touching but it is there.

 

[Passages]

Just went through the same issue a few months ago.

- Inspected all hoses and connections, all looked good.
- Replace Switch, no improvement
- Replaced duck bills, no improvement
- Replaced toilet seals - no improvement
- Replaced vac pump plunger and sealing o-rings, problem fixed.

 

[Pascal]

Then the issue is the switch. Note that the switch means the physical switch (which never fails) And the membrane, spring assembly.. the whole thing.