The best way to find the leak is to put some soapy water on the tube and look for the bubbles. The best way to fix the leak, assuming that it is a tire innertube is to purchase an innertube repair kit. You can get the kit from any bicycle shop or Walmart or kmart. The instructions are on the package and are easy to follow. Inner tubes are not that expensive. You might want to replace the tube. I would still suggest buying a patch kit so you arent going down a river and get left flat.
In the rubber part of what?
Put an inner tube in the tire.
depends where the leak is comming from. If its the flex tube about $125,if its not really bad it can be welded.
fix the vacuum leak
If the bypass hose on the 2000 Cavalier is rubber then the hose can be cut and spliced together with a coupling to fix the leak. If the hose it metal then it will need to be replaced.
locate leak , if it is close to a union such as a clamp or going from rubber to metal line, try tightening clamp or cutting a small length off rubber hose and applying a new clamp
Most times - new rubber vacumn hoses, sometimes new plastic hose connectors. A bandaid will work also if you have found the leak.
it depends if it is a metal line or rubber lines , if it is at a fitting or at the master cylinder or abs i can help you find these if you cant locate the leak
First off where is it? If it is in line then you can cut that section off and replace it with rubber fuel line of equal size.
Replace the rubber seal. You could seal with silicone but you would be unable to open it again.
spray some armor-all in all of the rubber weather stripping
You need to get a rubber-lined sleeve clamp and a good piece of rubber sheeting. For tempory fix use Duct Tape or Electrical Tape or Plumber’s Epoxy Putty,