wma64s wont spin fast enough?

Hi. I have a wma64s about 7 yrs old which will not finish a washing programme. It firstly filled up spun a couple of small spins as normal and then when it needed to spin fast it felt as if it couldn't. Then it stopped and displayed "on" on the display with the clothes still wet. I changed the brushes,clean the filter and pipe work and also the clear pipe from the pressure switch. Now it does most of the wash but goes down to the last minute but will not complete it just goes back upto 4 minutes and does it again