Older Kenmore: water pushes out drain while agitating

[Stefan]

Machine will fill up normally, then when agitation starts, water drains out. I can't tell if it is pumping or just pushing through. When level gets low enough, agitation stops while tub refills. Repeats throughout cycle.

It's an older, top loading Kenmore.

 

[handyman1962]

It sounds like the water is siphon right out of the drain. If this is the case check the end of the hose where it goes into the drain line it has to be a loose fit so air can get through. Also the drain can't be any lower than the washer or it will just siphon out.