Windshield and Headlight Washers

Most likely culprit is the little valves that are supposed to keep pressure up in the lines. They look like T fittings but are actually valves of a sort. There's one under the hood for the windshield washers and one under the headlight for the headlight washers.

You can repair them but replacing the diaphragm with a thin piece of latex glove, buy new ones ($17 usd), or you can just replace them with "T" fittings for 1/8" tubing.

The t fittings are a good way to test - if it works with the t fittings, then it's a valve issue.

OK ...this is somewhat odd. I didn't drive the car in a few days and today both windshield jets are working fine (a miracle mechanical recovery?) but now the rear washer stopped working.

I don't know much about the rear wipers... but if there's a check valve involved, it's typically the culprit :-)

Yes, and as has been previously mentioned, whether the check valve is one of the "tee" configuration or just the right angled ones, they are easily rebuilt. Just pry off the "cap" with a thin screwdriver or knife blade. Inside you'll find a membrane which will have hardened and/or broken. Scrap the old membrane and replace it with a small piece of latex cut from a rubber glove. Snapping the "cap" over the latex is what holds it in position, then trim the excess off from the outside.

The rear washer has a straight check valve that could be the problem. Another common cause is that the rubber pipe going into the rear washer assembly (inside the rear door) simply jumps off. In this case you can see the washer fluid pouring out of the bottom of the rear door. To access both you need to remove or release the interior door panel. This is done by pressing the centre part of the clips inwards before pulling them out and by unscrewing the interior handle. Now you can start separating the door and get a descent but not good access to the check valve.