We have a Simpson Aquapulse 513 washing machine?

The Simpson Aquapulse 513 top loading washing machine will go through the cycle up to rinse and then it slows down to a trickle and takes forever to fill up to continue to the next cycle. Water pressure on hot and cold from the supply taps are good and normal. All filters for the water are clean. Miss out the problem part of the cycle the machine continues as normal. What is wrong with the cycle. Thanks.