Slow coffee stream and smaller brew size with B70

Question

Keurig B70 11 months old.Cleaned B70 in accordance with manual (white vinegar) end of October and it worked fine - Thanksgiving week lots of use - really slowed down and brewed small cups (1/2 to 2/3 of size selected).Cleaned again (per manual except I used whole gallon of vinegar) and it seemed to work better flushing water through. But still too slow and small with K-Cup (Timothy's).We always fill unit with water from refridgerator (has filter/charcoal cartridge etc for ice maker) and we do not have especially hard water.I do not hear or see an air pressure blow out at end of cycle (although that was evident when flushing water at the end of a cleaning proceedure).Does this sound like a scaling problem, or could it be a weak pump??