Why no back windshield washer fluid comes out

I pressed the front and back washer buttons to empty the old washer fluid and poured 1 gallon of new winter washer fluid in the washer. Yesterday, I turned on the front windshield fluid button, fluid come out. However, no back windshield fluid come out when I pressed the back windshield fluid! Why?? 1 galon is not enough? Or something 's wrong?

Did you pour any fluid into the jug for the rear washer (in the rear of the van, not under the hood)?

Was the fluid you emptied water. Pumping it out won’t get the last of it which,
if it’s been cold, may have formed a frozen plug. A possible to eliminate.

My manual said washer fluid reservoir for windshield washers & the rear windown washer is shared.

It was regular non-winter windshield washer fluid.
It it has formed a forzen plug. How to unforzen it?

Park it in a heated garage for about 12 hours.

Any attached garage should do. Overnight temperatures ae below freezing, yet my car is still above 50 F in the morning.

Purge the bottle immediately and fill it with “winter mix” washer fluid. Then pump some out the windshield wash nozzles to purge the lines. Once you get the line to the back window unplugged, run some through to the rear washer nozzle to get that line purged of summer mix and filled with winter mix.

I use winter mix all year around. I’m too lazy to do the changeover, and I have less fluid to store.

I had an 87 Horizon and they had all the equipment but they forgot to drill the hole for the fluid to spray out of.

don’t know your year or make, but the hoses might be an issue. They may have become swollen or brittle/hard. Replacement hoses are very cheap at the parts stores. Buy a little more than you need, always handy to have certain items like that around. Of course, this is all assuming you have bad hoses, otherwise everybody else is spot on about a freeze plug.

Give it some time to if it was empty, it’s gotta pump all the way to the back.
Good Luck!

When you ran the summer fluid until the reservoir was empty, the lines still had summer fluid in them. When you added the winter fluid, you should have kept pumping until it pushed the rest of the summer fluid out.