how to shut off pump if full

[maple flats]

I am thinking "what if". If my 1000 gal tank fills to the top, I'm thinking (yes I know, I should have pumped it out sooner) I want to make a short out switch to stop the pump. I'm thinking if I make a device with 2 electric probes to mount into the tank lid, with maybe 1" between them, if the sap gets to that point it should short out the spark if I wire it to do such. The vac should soon fail and the overflowing sap would go into the moisture trap and with no vac should exit thru the bottom flapper valve that only stays closed by vacuum.
Anybody see a problem with this method? Of course I'll try to never have it get over full but I don't want to ruin the pump if it ever did overfill.
Anyone have a better idea to geep the sap from the pump in an emergency overfill?

[Dennis H.]

Look into one of those water sensor alarms that you place by your water heater. Some of them have aux contacts on them that you can then use to drive a relay or someother low current device.

I will look it up for you I seen them sold by a company called Smarthome.

[Haynes Forest Products]

You do not want line current in a tank of sap to short out as a float switch. DO NOT DO IT. Now for a great deal Ill sell you a set up that has 2 probes that will detect high and low liquid levels. But Im not trying to sell it to you. But there are better ways to do it.

[NH Maplemaker]

I thing you could also use a float switch. (pump up, not down )The round black one with the cord and female plug on the end. When your tank fills float goes up opening contacts and will kill power to electric motor on vacuum pump! If you are using a gas motor use a pump down switch. Have one side wire to a ground on motor and the other to spark plug. When the float goes up point will shut and will short out gas motor! You can get these float switch at most plumbing supply houses, also Home Depot. Hope this makes since and also helps you! JimL.

[markct]

i just have a moisture trap on the vac pump, just a pvc section capped with a drain on one end and a reducer down to 1.5 inch on the other and a raquetball inside that floats up and seals off the vac if the chamber fills with sap, saved my pump when my releaser stuck, havent had the vac tank overflow yet tho