Foodsaver v485 no longer seals

SOURCE: Foodsaver Food Sealer Vacuum V2240 T: Foodsaver Professional II Turbo. Vacuum pump work...

This is likely happening because the unit cannot detect that a vacuum has formed, and as a result, the unit never "turns on" the heating element to seal the bag, with the gaskets around the vacuum channel being the probable culprit. The Foodsaver gaskets will deform and/or dry out with time, just like in any device, but you don't necessarily have to replace them. I've tried this inexpensive solution on my own Foodsaver V2490, and it works perfectly.
Buy some food-grade silicone grease and apply it to both the upper and lower gaskets. I remove the gaskets and coat both sides with a thin layer of grease before replacing them in their respective channels. And since this grease will be absorbed and/or dry out with time, you will have to do this occasionally, so I also flip the gaskets (i.e. turn them over) whenever I apply the grease.
You can buy a 2 oz container of silicone grease at any dive store, or you can buy it over the Internet by searching for "Trident silicone grease".
This is a link where you can buy it for around $7.00:
Dolphin Dive Center
I do not work at this dive center, but I am a scuba diver and already had some grease that I use for the numerous rubber gaskets in my gear. The 2 oz. jar will last you several years, and you will find many other uses for it around the house since the grease will last longer than a spray.

SOURCE: Tillia Foodsaver VAC 370 won't stop vaccuming to seal

My Foodsaver 820 wouldn't stop vacuuming, and after fiddling with it and doing a little research, I located the vacuum switch on the circuit board and de-soldered it (verry simple, only 2 solder points). On the underside of the switch it looks kind of like an allen head screw. NOTE before attempting this, make note of how far the screw is recessed into the housing and/or count how may turns it takes to remove it! I removed the screw and spring and sprayed electrical contact cleaner in the holes and in the hole where there is a little brass disc. (Wear safety goggles for this) The little brass disc is what makes the contacts that turn the pump off after reaching the necessary vacuum. Mine was gummed up and stuck so it would never make contact to shut off. I reassembled it, and re-soldered it back on the board. I then put the whole thing back together and it works like new.

You could probably make the same repair without removing the piece from the board since there is a hole in the circuit board where you can gain access to the screw, but it will be messy. If you have any experience with soldering, it is about as simple as it gets

SOURCE: Need to get the bottom seal/gasket, foodsaver no

try using a small bead of high quality,high tempature silicon caulk. put bead over existing seal and make sure it cures thoroughly before closing or you will never be able to open it