Blaine,
If the hose is made from polyethylene, then you can fuse end caps/fittings on and make repairs with a No.14 fusion machine. You can find more information on a No.14 fusion machine at:
http://www.mcelroymfg.com/fusion/machines/no14.htm
If your still not sure of the pipe size and material, look for any markings along the length of the pipe or "hose." There should be a hot stamped manufacturer's name, spec and size, etc.
I am assuming you need 4" IPS (Iron pipe size) The actual OD is 4.5" with a circumference of about 14 1/8". If the hose is ovaled out you can wrap a tape measure around it and measure the circumference and compare it to the following charts to get the exact size. (this is very important)
http://www.mcelroymfg.com/fusion/solution/pipesize.htm
For more information on where you can purchase or rent machines see our distributor locator at:
http://www.mcelroymfg.com/fusion/buyit/buyit.htm
Most distributors stock a complete line of fittings as well.
Hope this helps.