Hello!
Ie been making my own pumps for about 4 years now. I’ve used many items over the years but here is the easiest way I e found for the lowest price.
A beverage dispenser - the key is finding one with the right spigot that will find the tube from the brake bleeder.
https://www.amazon.com/Berglander-Dispe ... 64&sr=8-77
Next you need a brake bleeder kit-
https://www.amazon.com/ZEAJSRU-Handheld ... YXRm&psc=1
Finally a silicone funnel to use as a seal, what you’re going to do is cut off the bottom few rings with a pair of scissors and slip the large ring over the jar rim. the orange one should work in this pack, however you need to make sure the diameter is the same as the jar.
https://www.amazon.com/Silicone-Collaps ... 23&sr=8-34
Now all you need to do is connect the tube from the pump to the spigot on the beverage dispenser and add the seal to the top of the jar, add some warm water and get your heating pad and you are ready to go.
The other tip I will share is if you have a bigger jar and can’t find a silicone seal you can use foam edging to make a seal. Just cut the piece to size and use some electrical tape to get a good seal.
https://www.amazon.com/Baby-Pre-Taped-F ... 116&sr=8-3
Happy to share some tips or answer any questions, feel free to send me a message.