Is there a seal between the nozzle and the tip? I have glue leaking out everywhere??

yes you can lock tight glue for rubber and plastic.(tube glue not superglue it's like a gel) thin amount of glue locks it in place or a blob of glue turns into a rubber seal. also stops cracking from same crack. used it myself works great.

The cost of a glue gun varies between $5-$20 for a good one.
The glue gun works based on heat, in the front of the glue gun there is a heating element, once you install the glue cartridge and press the trigger the glue cartridge is pressed thru the heated element who melts the glue forcing it thru the front nozzle

Here is a great blog on how to change a glue gun nozzle. But big things to remember, preheat the gun, use gloves or a wrench and be careful! If you don't preheat your glue gun, you are likely to strip the nozzle and then be unable to use it again and may even break the gun. Hope this helps!

http://www.gluegun.com/blogs/tips-tutorials/7918501-how-to-change-a-glue-gun-nozzle

The glue might not work because glue can melt and since it is close to your vacuum motor that creates heat causing it to melt so I personally would just go buy a new one they are like 20$ but if you want to keep on trying glue I think super glue would be your best gues

sometimes the trigger can be very hard to pull. if the glue is melting but not coming out the nozzle, where is it going?

hi, is this from around the shaft? if so a seal is fitted to this, it is easily replaced by removing the gearchange lever, und using a small sharp pick to push between the shaft and the seal, with not much effort you can pull the old one out,clean around the shaft and seal area and gently push the new 1 in useing even force all round, TIP IF YOU LAY THE BIKE DOWN ON ITS RIGHT SIDE YOU CAN REPLACE THE SEAL WITHOUT REMOVING THE OIL.

try to heat the glue up more so it melts. if the glue in the nozzle is clogging the works and not heating up enough to melt, try to remove it with a razor blade

High-temperature silicon glue will probably work ok. Be sure to clean the hole with alcohol and allow 24 hours for the glue to cure. Epoxy would be a better seal, but it doesn't adhere to plastic very well. Hope this helps!

try gorilla glue

Plug the glue gun into an electrical outlet. Make sure it is placed in a secure place, away from flammable items. As the glue gun heats up, a little bit of glue might drip from the end so you won’t want to leave it on a wood table or on carpet. Insert a glue stick into the back of the glue gun. If the glue gun already has a glue stick in the chamber, keep a second one in reserve nearby. Gather the materials you want to glue together. Hot glue works exceptionally well on thick fabrics, dried flowers, Styrofoam, wood and plastics. Since it leaves a thicker residue, it is not the best choice for thin papers, fabrics and ceramics. Check to see if the glue in the gun has melted by squeezing the trigger slightly and touching the tip to a test piece of paper. If the glue comes out easily, the glue gun has heated up fully. If the trigger is hard to pull, wait a minute more for the gun to heat more completely. Pick up the glue gun and squeeze the trigger slightly while you draw a thin line on one side of the item to be glued. Immediately place the other object to be glued on the glue line, pressing firmly. Hold the two pieces together for about 15 seconds. Test to see if the item still holds when you remove one hand. Let the item set for a few minutes in order to “cure.” Once the glue has dried fully, use a fingernail to scrape away any of the excess glue.