washer fluid tank dries out over night

[fgross2006]

I'm sure this topic was posted before but I never did get a resolution on this.

My 84 LX washer fluid tank doubles with the anti freeze overflow tank. I actually put this in and it was NOS when i got it about 5 years back when I just got my car. I have never been able to keep washer fluid in the tank more than a day.

Sounds crazy but it just disappears. I have tried changing the rubber tubing to smaller tubing twice already. I flipped the tank upside down and put a bead of clear silicone all around the perimeter of the lid, which is not supposed to come off anyway. Last week I took the tank out of the car. Put it on my work bench and filled it with water with the rubber tube plugged with a screw. In an hour not a drop of water came out or left so much as a drip on my work bench. I put the tank back in, with smaller tubing and filled the tank to the top with blue washer fluid.

Next morning every drop was gone and no water anywhere in the engine compartment or on the ground below. Literally everything was bone dry yet this tank was 100% empty overnight.

Has anybody dealt with this strange phenomenon? I hate to have to buy an aftermarket tank. it ruins the look of the engine compartment to do that.

[emerygt350]

i had a similar issue but it was going over into the coolant. new sealant on the top fixed that. no clue what is happening to yours!

[fgross2006]

Well I pulled the tank again today. there is an opening between the washer tank and the anti freeze overflow tank but water only runs out if I tilt the tank backwards when its full. Other then that theres no reason for all the fluid to run dry over night. It cant evaporate that fast even in extreme heat.

I swapped the elbow fitting that connects the tube from the tank to the main line running to the windshield. I got one that reduces to a smaller nipple and replaced the hose with a yet smaller one to the tank. I took the liberty of dabbing a small smear of RTV around the nipples before slipping the rubber hose onto them. Hopefully it will leave it nice and tight.

I also pulled out the washer pump and smeared a bit of RTV around the rubber stopper. It's not supposed to need it but it can only be leaking from the pump or the hose. Lastly i put dry white napkins under the tank and under the hose couplings. Will see tomorrow if the tank is empty or even low, is the napkin wet or stained blue.

[fgross2006]

It's now been 3 days and the washer tank is still full to the top. Not a drop lost so between the tube connection and the washer pump I managed to seal up whatever was leaking.

[emerygt350]

yeah, probably was all evaporating before you could figure out where it was coming from...

[fgross2006]

yeah, probably was all evaporating before you could figure out where it was coming from...

I'm still losing washer fluid just not as fast as before. tank is about 1/2 inch lower than when I filled it 2 weeks ago. I haven't pumped any fluid. I may have to accept it as it is. All I can think is evaporation since the tank shares space with the radiator overflow.