Technical Rear screen wash hose leak

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Technical Rear screen wash hose leak


New member
Apr 29, 2019
Tips for investigating potential rear screen washer hose leak:

First thing:– DISCONNECT THE BATTERY ( I think the seats have airbags (but could be wrong on this) so better to play safe).

Easy(ish) and quick(ish) way to carry out investigation is to start by removing the trim from the passenger side sill (the bit you step over to get in the car).

This is held in place by two Philips head screws – one to the bulkhead side of the bonnet release catch and one at the bottom of the B pillar – and five our six clips (forgot to count them) all bar one of which are moulded into the trim.

Remove the two Philips screws then lift away the trim at the bulkhead end whilst pulling the top of the trim at the door hinge side in the direction of the door lock striker plate – this will release the moulded clip from the body (will probably need a flat bladed screwdriver or trim removal tool to get a purchase on this).

When this is loose, pull the rest of the trim vertically upwards from bottom which will release the rest of the clips and allow you to remove the trim exposing the wires and rear screen wash hose that runs down this side (this allows you to see more than 50% of the hose run).

Reconnect the battery, turn the ignition on and get someone to operate the rear screenwash whilst you keep a close eye on the hose run from the bulkhead to the B pillar to see if any water comes out – a torch will be handy for this.

If you have a leak in this area it should be very obvious - water will appear very quickly (and if it is where it is not wrapped by tape it will spurt out).
If you have a leak but it is beyond the B pillar then you have a lot more work to do - not covered here.

If you find a leak, remove wiring and hose bundle from the clips and cut the tape so that you can free the hose from the wires. Cut out the leaking section with a sharp knife (so you don’t flatten and stress the hose) – my burst was 2-3mm wide. Dry out the inside of the hose with kitchen roll or similar.

Info for repairing the hose - I used:

Silicon RTV (bathroom sealant)
Internal hose coupler
Tubing to go over the hose
A bit of fine sandpaper
Electrical insulating tape or similar

The hose is 7mm OD

I used a 4mm coupler (tried a 5mm but couldn’t get it to fit) -
7mm ID rubber hose -
I also bought a set of trim clips since I lifted a lot more trim and broke some clips -

Cut a piece of the rubber tube to be quite a bit bigger than the length of the internal coupler and put a couple of bits of tape on the door seal to show you where you want it to go when it is over the join.

Lightly sand the hose coupler, the outside of the screenwash hose and the inside of the rubber tube to give the RTV something to key to.

Put the tube over one piece of the screenwash hose and move it out of the way.

Put RTV on one side of the internal coupler but keep away from the end – you don’t want any going into the hose, coming loose at a later date and blocking the jet – and push it into the hose. Put RTV on the other side (again keeping away from the end) and push the other end of the hose on to it.

Put more RTV onto the outside of the hose and slide the rubber tube over it to align with the tape you put on the door seal. Put RTV around each end and leave for 24hrs to set.

After 24hrs wrap the rubber tube tightly with insulating tape (bells and whistles here – could be just my paranoia).

Test the rear screenwash and check for leaks. If OK:-

Tape up the hose and the wires and put back into the clips (if the leak was at a clip and the repair makes it too thick to go in there is space for the hose to run outside the clips.
Put trim back; carpets should dry out in due course (bigger job if you want to lift the passenger footwell carpet)

Hope this is of use.
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Thanks for that.
Would if I knew how to do it.

I also posted yesterday identifying that if your rear screenwash water doesn't come out almost immediately then you likely have a leak.