The drain hose in my washing machine is backing up. I had to replace the pipe that the hose sits in. It is about 3 inches shorter than the old one. Not sure if this has anything to do with the back up. It starts to drain fine, and then water comes out the top of the pipe.

That stand pipe should be between 36 and 39" depending on the make of washer. It must also be at least 2" in diameter and trapped. If you still get a backup you will need to rod out the drain with an auger, run about 10' of rod back and forth. Another home remedy is to mix a cup of baking soda with a cup of table salt. Dump it down the stand pipe and add a cup of vinegar, don't put your face over the top of the pipe. Tomorrow dump a bucket of really hot water down the stand pipe.

Thank you, I'll try it.