Today we’re going to discuss changing your windshield washer pump. We’ll go ahead and categorize this task as an intermediate level project (if you’re thinking beginner, intermediate and advanced) You’re going to need some tools to knock this project out. Here is a list of what you will need:
- voltmeter or 12VDC test light (to check voltage at connector)
- piece of hose / siphon (to remove as much washer fluid as possible)
- small flat tip screwdriver
- 10mm socket & ratchet
- vise grip or decent pliers
- brass or steel brush (old toothbrush also helpful)
- Q-tips for additional cleaning
- hot water (works well at removing loose rust/dirt)
- CRC Electronic Cleaner (MAF Cleaner works too)
- Electrical tape (if housing is cracked)
- about 45-60 minutes (a refreshing drink wouldn’t hurt either)
First siphon as much washer fluid from the tank as possible. If your tank is already empty then great! But if you have a lot of fluid still in the tank it would be best to drain it or be quick with the tank removal so that all that fluid does not wind up all over the place.
Then remove the 10mm bolt holding the windshield washer tank in place:
Unplug the electrical connector from the washer pump:
Lift the washer tank up slightly and using a small flat tip screwdriver gently pry the black plastic bracket tab from the tank and remove the bracket:
Remove the washer jet hose from the pump outlet (if tank is full be prepared for fluid to come gushing out):
Disconnect electrical connector for the ‘washer fluid low’ sensor:
The washer tank & pump can now be removed from the engine compartment. If you have to drain the tank now; do so. Once drained remove the washer pump by pulling the pump straight up.
If you have a new washer pump then place the new pump into the tank and install everything in back into the engine compartment. If you are going to repair your washer pump then continue reading.
Inspect the washer pump for damage (my pump has a large crack along the top half of the housing):
Separate the top half of the pump housing from the bottom half using the small flat tip screwdriver (use a twisting motion instead of prying):
Once the top half of the pump is loose remove it. You should end up with these two parts:
Using the flat tip screwdriver GENTLY pry the side tabs the connect the top of the pump motor to the can (metal housing):
Once the tabs are moved gently remove the top half of the pump motor from the can (metal housing):
The underside view of the motor top. You can see the electrical components and the motor brushes (use q-tips to clean between the brushes):
A view of the electrical pump motor. Rust has seized the armature to the field magnets in the can and will not turn by hand:
Using a vise grip at the lowest setting needed to grip the armature axle turn gently twist the axle until the armature breaks free from the field magnets:
Once the armature can be moved gently remove it from the can (this armature shows signs of rust starting from the bottom – possible leak within the pumps impeller housing):
A look inside the motor can and field magnets (lots of rust from the bottom – up):
Using hot water, your finger, an old toothbrush, a metal brush and q-tip remove as much rust / dirt / debris from the pump housing:
Using a metal or brass brush clean all contaminates from the electromagnets. Be careful NOT to break the armature coil wires or damage the communicator (small brass piece atop the electromagnets). Clean that with your finger or VERY gently with a brass brush:
Once you have as much as you can clean; use the Electrical Cleaner (MAF Cleaner) to rinse off all the components. Let the components air dry. Before assembly blow air into the outlet port of the pump assembly. If the impeller is still working you will hear a whirling noise as well as see the movement of the white plastic piece at the inlet port.
To assemble, be sure to insert armature back into pump housing (can) with the notched end of the armature axle at the bottom. You will have to twist gently to get armature to seat correctly in between the field magnets:
The armature is fully seated when the electromagnets are just below the top of the field magnets (can assembly):
Now line up the pump motor top with the housing by using the plastic tab and notch available (the blue capacitor is right behind the plastic tab) – only line up these points – DO NOT attempt to seat pump motor top yet:
With the tab and notch aligned look at the underside of the pump motor top to get a view of the motor brushes:
Use the flat tip screwdriver to gently move the motor brushes aside in order to secure the pump motor top to the housing (the brushes should end up resting on the brass communicator):
With the motor top fully seated; bend the metal tabs of the motor can inward to secure the top to the rest of the housing (I found it easier to first tap in from the side of the tab and then from the top):
Carefully line up the top half of the pump housing with the pump leads and secure the top half to the bottom half. Be even with the pressure and gentle so that you don’t force the top half farther than it needs to be or you might end up cracking it.
If you have a battery charger or a 12VDC power supply you can test the washer pump motor before installing into the tank. My pump kicked on right away using the maintenance charger I use for my motorcycles.
Now would be a great time to flush out your windshield washer fluid tank. Washer fluid can gel and gum up the tank over time (use LOTS of hot water):
Also flush out your washer pump filter / seal (this one was covered in blue gel before I washer it):
Now place washer pump filter / seal back in the tank opening (make sure it is flush not half in like this picture):
This is a properly seated washer pump filter / seal:
Place repaired washer pump assembly back on the tank (you can see that I used electrical tape to wrap around the top half of the washer pump due to the crack it had):
Install washer tank & pump back into engine compartment. Connect ‘washer fluid low’ sensor, washer jet hose, black plastic bracket to tank, washer pump connector and 10mm bolt to metal body. Make sure tank seats properly at the bottom (there are small alignment tabs that go into the metal).
Now add washer fluid to tank, key on (position 2) and activate the windshield washer system. If the washer jets spray fluid then congratulations on a job well done:
We’re All Done!
Now where did I leave the refreshing drink I had made myself at the beginning?
Sources: BMW Forum, E46 Forum
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