VW Golf mk4 rear washer repair

A common problem on the Mk 4 Golf is water leak from the rear screen washer system.

More often that not, this problem manifests itself within the tailgate and causes water to be directed onto the electrical switch within the tailgate lock mechanism. The result of this problem is that reduced flow may be seen at the washer nozzle, and the ‘tailgate open’ warning light may appear on the dashboard whilst driving. In the worst case, the alarm system can be fooled into thinking that the tailgate is actually open thus preventing the central locking system from activating to lock the car, or causing false triggering of the alarm off once the car is locked.

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The problem area within the tailgate is the connection between a flexible piece of washer hose and a fixed fitting on the end of the wiper motor shaft, through which the washer water is fed. A VW dealer is likely to declare that an ‘incorrect screenwash additive’ has been used in the system previously, and this has resulted in a blockage of the washer jet causing the pipe to be blown off. However, in truth it is just a weak design that cannot cope with the high pressure and flow of the VW washer pump particularly if the nozzle freezes during winter.

To access the washer pipe connection, first you will need to remove the internal trim panel covering the lower half of the tailgate. This panel is retained by one screw inside each of the two internal moulded handles on the panel, and a series of trim spring clips that must be prised away by pulling the panel away from the bodywork.

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Once the main body of the panel is loosened, care must be taken to release the panel at each end where it joins the internal grey (or beige) screen surround.

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Once the internal panel is removed, it will be clear if the washer pipe has been leaking by the dampness or blue coloration of the fibre sound insulation that lines the trim panel. The plastic connector that is part of the end of the washer pipe should also be clearly visible, either connected loosely to the wiper motor or hanging loose on the end of the pipe.

Rear washer repair Repair #1

A simple job may be to simply reconnect the pipe to the wiper assembly, but this is likely to be only a temporary solution as the problem may reoccur in the future. If you choose to retain the VW connector then inspect it closely to ensure that it is not cracked and that it clips back onto the motor firmly.

On my car the connector was cracked so it would never seal correctly and an alternative repair was necessary.

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Rear washer repair Repair #2

If the pipe connector is damaged, or you simply don’t trust it to not leak in the future, here is a simple repair solution to remove the weak connector.

Firstly, buy a length of 3/8” dia windscreen washer pipe from your local motor factors. You will only need a length of approximately 50mm for this repair, but it is cheap even if you have to buy a 8’ long pack from Halfords. You will also need a sharp Stanley knife, a couple of small cable ties and a mug of boiling water.

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Chop off the VW pipe connector from the washer pipe, but try to retain a small section of the enlarged diameter section of pipe where it was moulded onto the back of the connector. Cut a length of approximately 50mm from the new washer pipe and place it in the hot water for a minute or so until it softens. Using a little washing up liquid if necessary, push the new pipe over the outside of the old pipe as far as it will go whilst retaining at least 15mm of new pipe beyond the end of the old pipe.

Reheat the end of the new pipe and then push it over the fitting on the wiper motor. Wrap a cable tie around each end of the new pipe for additional security, and if necessary use another cable tie to hold the washer pipe against the nearby wiper motor wiring loom to prevent any kinking of the new pipe.

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If the inside of the tailgate is wet from previous washer pipe leakage then use an electric hairdryer to dry the lock mechanism out thoroughly before reassembly.

Squirt some WD40 or similar water dispersant onto the back of the tailgate lock and switch assembly, to ensure that any residual moisture does not find its way into the switch.

Reassemble the interior trim, taking care to align the trim clips with the holes in the tailgate where possible. If the sound deadening panel is wet from the leaking washer pipe then allow it to dry out fully before reassembly to prevent any alarm problems.

Now enjoy the new found pressure in the rear washer system and marvel at how water from the rear washer can now spray onto your front windscreen!

Rear washer repair Repair #3

An alternative symptom of a failed rear screen washer can be a break in the feed tube inside the wiper motor assembly, which allows the washer jet to rotate with the wiper arm as described below by Tim Price:

…..The tube that passes through the motor and carries the wash fluid is made from brass and I have found that water collects in the collar that holds the brass tube (near to the jet).  The collar is made from alloy/steel and corrodes over time.  The corrosion eventually holds the brass pipe at the jet end and causes it to twist through 90 degrees when the wiper is activated (I saw this happening).  Before long the brass pipe shears off and water starts pissing out as described. 

The solution is to dismantle and remove the old pipe, drill out the collar to a more generous dimension (7mm).  Then you get a similar diameter brass tube (B&Q) and use that, bending through 90 degrees and following the path of the old tube, connect up and you are away.  It is a good idea to grease the collar that supports the tube.

Since the repair, mine has been faultless!  (2 years)

If you have performed this repair or have any tips to add, please use the comments section below and share your experiences with other mk4 owners.

This article was provided courtesy of www.golfmk4.co.uk.
We believe the site is no longer live, so we have rescued the article and placed it on our site along with some other information.

If you enjoyed this post, subscribe to our also useful Newsletter, you can read more about it here – CarBasics Newsletter

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