E39: Replacing / Unclogging the Washer-Jet Pump

If you think your pump is faulty then check this post first - Windscreen Washer-Jet System Problem.

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Removing the pump is easy, but getting to it is quite involved due to the amount of under-car panelling the E39 has.

PROCESS:

1. Jack up the o/s front of the car and detach the plastic mud-guard by removing the 3 hex-head screws that hold it to the wheel-arch. using a 7mm wrench.

2. Lift off the plastic under-tray that sits to the rear of the wheel-arch by removing the 5 plastic-studs around its edge. If you lack a took for pulling out this kind of stud then lever the head of the centre-pin out a few mm with a flathead screwdriver and then slide it clear with pliers. The body of the stud should now slide out easily.

* The car may need lowering to remove the under-tray and re-lifting, as the jacking-point lies in the centre of it.

3. Remove the 7 hex-head screws around the inside of the wheel-arch. as well as two at the leading edge of the under-tray, unseat the inner wheel-arch from around the lip of the wheel-arch itself and pull the plastic inner-arch down out of the way.

* The water-tank for the windscreen and headlight washer-system is located just behind the wheel-arch, below the front of the driver's door. Not the Intensive cleaning-system, which has both the tank and pump under the bonnet.

4. Unplug the wire-connector from the pump in centre of the tank**, by sliding a flat screwdriver into the clip and lifting it upwards.

5. Pull the slim hose-connector clear of the central pump** and allow the tank to drain.

This is a good point to test the washer system one last time to make sure it isn't a blocked hose and the pump is getting no water.

6. Gently twist and pull the pump upwards about an inch out of its mount, then remove the black rubber-bush it sits in.

7. Flush the tank several times by pouring water into the filler-nozzle under the bonnet and allowing it to drain through and clean around the lip of the pump-mount. Check the pump for clogging.

8. Replace the rubber-bush to the tank and, using the new pump if necessary, reverse the procedure.

** The pump in the centre of the tank with the slim hose is for the windscreen washers. The left-hand pump with the larger hose is for the headlight washers.

*** The black connector on the inner corner of the tank is the level-indicator probe. This is also a push fit and the best place to drain from, after removing the wire-connector as above.