I have a 2011 focus 1.6 tdci with a windscreen washer problem.

The fuse was blown so i decided to remove the wing inner and remove the reservoir to have a look. The usual suspect black mucky stuff in the filter so i cleaned everything out and tested the pump with clean water and everything seemed fine.i got rear windscreen wash no problem but nothing on the front. The pump sounds fine on both operations but no water on the front. I swopped the water connections on the motor and then the front operated perfectly but no rear wash. Is it possible for the pump to fail on one outlet only or am i missing something obvious ?Many thanks for any help in advance. 

This morning i got a new reservoir pump £15 and fitted it and decided to check along the lines to the windscreen. Boy were they mucky and the check valve was mucky so i gave it a good spray through and ran clean water through both front and back and every thing is working as it should. This is the first time in my 37 year driving i have had to do this and its a reminder that where theres water theres muck.