can I fix a karcher 1400 # unit model 79C2?

I have a Karcher model 79C2. It acts like it is only pumping on the half cycle. perhaps a cylinder or ring is broken. should I try to repair or forget it and buy a new washer. It's a 1400 pound unit that I have been happy with for general cleaning around the home. cleans plastic siding quite well, and decks.