You may be able to use some kind of adhesive or sealant because that washer
tank is not under pressure like the overflow tank is.....

It might be worth a try before replacement.

Do we know what type of plastic it is?  Polyethylene perhaps?

Please post them to the group, I am more than interested also.

Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's
Canadian Off Road Trips Photos:  Non members can still view!
Jan/06 http://www.imagestation.com/album/pictures.html?id=2115147590
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Instructions for plastic bottle repair.

I don't guarantee this because I wasn't convinced it would work until
I tried it.

The product I used was named Permapoxy 5 min plastic weld. www.permatex.com
item# 84125

I used it to fix my overflow reservoir in 2005 and it hasn't leaked a
drop since. But your WWAF bottle may be a totally different plastic.

I removed the reservoir and rinsed it out. The crack was about 3
inches long and easy to find on the bottom flat surface. When it was
dry, I roughed up the area for about 3/4 inch (2cm) around the crack
with very coarse sandpaper, then finer sandpaper (60-120). I did not
drill at the ends of the crack to prevent it from spreading. I
squeezed out the 2 part epoxy onto waxy paper and mixed it thoroughly
with a wooden coffee stir stick. Then I slathered it over the crack as
thick as possible for about 1/2 inch on each side of the crack and
past the ends. I left it to dry as long as possible before
reinstalling it. I removed it about 7pm and reinstalled it about 6am
and drove to work. I topped it up there and it has been fine since.

I only bought one package and used about 3/4 of it for this fix.

If this doesn't work, I think I might have a good bottle on my 89 XJ
partsmobile I could send you if the postage is less than a new bottle.
I'll check in the morning.

Good luck! Let us know how it goes.

Merrill