I looked in Bently's manual and searched this forum. Yesterday I changed the headlight washer pump because the fluid was leaking out of the cracked pump case. I had the reservoir completely out on the work bench. There were two pumps, one at the bottom with two hoses that go the the windshield. The other pump I replaced has one larger hose that goes to the front of the car. The question is, how the heck does the rear window washer work. While playing with the controls it managged to squirt fluid on the rear window once. One of the pumps runs everytimg the stalk is pushed forward. What makes the fluid go to the rear window? The headlight washers work great with the new pump installled.

I would really appreciate any enlightenment, like I said the Bentley manual does not discusss the Avant in regards to the rear washer.

Lou

 

Any help?

 

The bottom pump should have two "line-out"s on it. One goes to the windshield, one goes to the rear hatch. Pushing forward on the stalk should only jet washer fluid to the hatch. I just recently replaced both of my pumps.

 

Thanks for the reply brrman.

The pump on the bottom does have two lines from it. I assumed it was one for each side fo the windshield. Is the cylindrical piece on the side of the pump some type of valve that only lets fluid go in one direction at at time, based on which way the staulk is pushed? That would explain another mystery I witnessed while draining the tank last weekend. I took one hose off and fluid drained out, I took the other hose off and nothing came out of it. Sounds like one side is normally open and the other is closed, they both change state when power is applied. Sound reasonable?

Lou

 

yep - sounds perfectly reasonable to me.

 

I ordered a new pump, when I get it installed I will autopsy the old one. It will be a couple of weeks at least.

Lou

 

Well, I finally got around to changing the windshield/rear window washer pump for a new one. I dissected the old one apart to see how it worked.

In essecence it is like two pumps in one with a directional check valve if you will, attached. When the impellar turns in one direction the check valve diaphragm is pulled and pushed in the direction that allows flow from the desired port. Reversing the direction of the impellar rotation reverses the direction of the diaphragm movement allowing flow to go out the other port.

Prettey clever if you ask me.

Lou

 

Do you know where the rear washer tube is exactly routed from the reservoir to the rear wiper ?
I need to trace it.