There's an excellent product called Extreme Tape. I got it a Part Source here in Ontario. It is a silicon self-adhering tape that bonds to itself. It is electrically insulative, air tight, watertight, withstands extreme temperatures and high pressure. I used it on a big crack at the underside of my turbo intake air hose while I waited for the replacement hose to arrive. That was 6 months ago. I have the new hose but figure I'll save it until the repair job leaks. I bought a 2nd roll of the extreme tape for road side repairs, as it could be a real life saver for any hose that blows a leak.

Al