How can I fix Bosch WFF 1401?

This machine runs through a normal wash cycle but at the spin stage the water is pumped out of the machine and will not progress to a spin. I have removed the top cover and can hear a 'clicking' every 10 seconds from the top side mounted panel behind the circular programme dial. There are two components on this panel, about an inch square or less with red covers and these are the parts making the sound. The covers pull off but I can see no way of pulling off th parts and anyway don't know if the problem is here or on another sensor. Any help please