Dissappearing windshield washer fluid

fluids
windshields
#1

I have a 97 Olds Bravada that constantly loses it’s washer fluid. No visible leaks; have replaced both pumps (front and rear windows). Stays full if the vehicle is not driven, but when driven, the fluid level just keeps going down! Never a drop on the garage floor, either. I even left it at the dealership for 3 days for them to drive. They admit it’s leaking but couldn’t find the source of the leak. Can anyone help? Thanks.

#2

Does it lose the fluid when driving (and not pushing the fluid/wiper switch) or does it lose the fluid only when you drive and activate the switch to wash the windows? I’ve had the latter happen once, it was a broken joint of two rubber tubes somewhere in the trunk lid.

#3

You can use a hand pump, lightly pressurize the washer system backwards from the tubes going to the nozzles, and see where the water comes. You’ll have to plug the vent hole in the cap of course.

If you really want to have some fun put the car on ramps, engine off, ask your buddy to slide under on his back to look for the leak, and then pressurize the system…

Sorry, couldn’t resist…

#4

Even though there are two pumps, I believe that there is only one WW fluid tank on this vehicle. The hose that leads from the under-hood tank to the rear window washer is very long and there is undoubtedly a separation in the hose somewhere underneath the vehicle.

It may take the forces generated by acceleration to cause it to leak, thereby preventing a visible leak while it is parked. If someone searches thoroughly underneath the car (or wherever the hose to the rear is routed), the separation should become apparent.

#5

When you say the pumps were changed you mean that the container was changed too? Maybe a small crack in the container, probably around the fluid level and when the car starts moving the fluid leaks and evaporates at the same time. I will be putting some colorful fluid and start looking for traces in there.

#6

Do you get a good powerful spray out of your washer nozzels? I have seen the tubing leak (if your spray is good this is unlikely).

Another possibility is that your are missing a chech valve and the air rushing by the nozzel is pulling the fluid out.

You would have to pull up the carpet to find a leak (in the rear is where I found one leak,not so hard to pull up the carpet).

#7

I had the problem of poor washer fluid mileage on an old Astro van I used to drive for work. It had the nozzles on the wiper arms and so I’m pretty sure what was happening was that every time after I used the washers the air rushing by would cause all of the fluid that was in the lines after the pump to dribble out. I think ordinarily, this shouldn’t happen because it’s a sealed hose but I’m guessing there was a leak somewhere that only leaked air into the system, serving as a vent, but not fluid out so I couldn’t find it. Since I wasn’t paying for washer fluid and I had plenty of opportunities to top off every time I filled up the old gas guzzler, I never worried abut it too much.

The thing to do might be to have the mechanic run the washers so the tubes are full of fluid and then hook the hose up to a vacuum pump (or, if there’s a trainee around have them suck on the tube) and see if an air bubble develops anywhere on the line.