just got thru replacing the little valve under the hood blanket that distributes water to both washer nozzles. the nozzles had quit delivering water and the pump,resivoir, and lines had all checked out ok. one hour to the dealer in travel time and five dollars later the problem was solved. parts person said they get dirt in them and clog up. very curious because the fluid looks like it passes thru two filters before hitting the little "T" looking valve. pulled it apart and found no dirt at all. It operates as a distributio valve and check valve. a very small diaphram is held against water pressure by the smallest of springs. since we have had no rain for a long time i had not used the washer. the little diaphram had become stuck to the base and could not be dislodged by water pressure. when i pulled the top off with a pocket knife and reseated the
diaphram it worked perfectly.
Five dollars to Volvo. an education for me. a tip for the interested.