A6 Rear Wash/Wipe arm going a little beserk

[Norfolkchris]

Mine had similar symptoms and I replaced the motor last week. (Also ended up replacing the wiper arm because it had corroded itself to the motor shaft. I bought a pulling tool but still couldn't remove it without destroying it)

Having read a few posts elsewhere and stripped the old one down I believe that the root cause (or at least contributory factor) of this problem is blocked washer jets. (Mine were blocked and extremely difficult to properly unblock because there must be an uneven internal profile which stops you poking the crap out. I would actually recommend replacing the jet at the same time).

There is an internal seal which has to deal with the shaft motion and I suspect it wears with time. When the jets are blocked there is an increased pressure differential across the seal which allows washer fluid to enter the wiper gearbox. My mechanism was heavily rusted. There is also a small circuit board which controls the wiper motion and sometimes this can get flooded too. Either or both will cause erratic behaviour or failure.

[rjsdavis]

Mine had similar symptoms and I replaced the motor last week. (Also ended up replacing the wiper arm because it had corroded itself to the motor shaft. I bought a pulling tool but still couldn't remove it without destroying it)

Having read a few posts elsewhere and stripped the old one down I believe that the root cause (or at least contributory factor) of this problem is blocked washer jets. (Mine were blocked and extremely difficult to properly unblock because there must be an uneven internal profile which stops you poking the crap out. I would actually recommend replacing the jet at the same time).

There is an internal seal which has to deal with the shaft motion and I suspect it wears with time. When the jets are blocked there is an increased pressure differential across the seal which allows washer fluid to enter the wiper gearbox. My mechanism was heavily rusted. There is also a small circuit board which controls the wiper motion and sometimes this can get flooded too. Either or both will cause erratic behaviour or failure.

Thanks for this.

It's an annoying problem. My jet (or at least the cap) is defo not blocked - whenever you activate the rear wiper, water floods out onto the screen with no problems at all.

The other day, I did sit in it in my driveway, and use the rear washer for ages. I checked the boot afterwards, and there was no water hanging about in the tailgate. Yesterday, I could hear water swishing about as I opened the tailgate, so it seems likely that rainwater is finding it's way in, rather than it being a leak from the rear wiper system.

Looking at the boot, it has been suggested that the seals behind the tailgate lights are the likely suspect. I will check this out when I get another motor and look to fit it. However, what I don't understand, is how this affects the electrics of the wiper motor in any event? The lights are a good deal lower than the wiper and wiper motor, therefore, even if rainwater is getting into the tailgate behind the lights, how can it possibly affect the wiper motor internals?

[Norfolkchris]

Thanks for this.

It's an annoying problem. My jet (or at least the cap) is defo not blocked - whenever you activate the rear wiper, water floods out onto the screen with no problems at all.

The other day, I did sit in it in my driveway, and use the rear washer for ages. I checked the boot afterwards, and there was no water hanging about in the tailgate. Yesterday, I could hear water swishing about as I opened the tailgate, so it seems likely that rainwater is finding it's way in, rather than it being a leak from the rear wiper system.

Looking at the boot, it has been suggested that the seals behind the tailgate lights are the likely suspect. I will check this out when I get another motor and look to fit it. However, what I don't understand, is how this affects the electrics of the wiper motor in any event? The lights are a good deal lower than the wiper and wiper motor, therefore, even if rainwater is getting into the tailgate behind the lights, how can it possibly affect the wiper motor internals?

I agree. I don't see how water entering low in the tailgate can affect the wiper motor at the top. I said above that I thought blocked jet were contributory to the internal water leak problem but I think the leak could still happen without this. When I took mine apart I could see that the seal relied on a rusting metal tube rotating inside a rubber seal - it's bound to leak to some extent. You can actually inspect it without removing the wiper or motor. After removing the tailgate trim panel the motor is exposed. You can unclip the washer hose and then remove 4 or 5 small screws that secure the cover plate. Take it off and it will immediately be clear whether you have a leak. All the steel moving parts inside mine were heavily rusted.

[dean warren]

How easy does the plastic boot trim come off? I have to swap my motor, that was blocked


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[Norfolkchris]

How easy does the plastic boot trim come off? I have to swap my motor, that was blocked


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I'm not sure I would say easy but I followed the video below which is accurate. You need to pull pretty hard to release the clips. The hardest part is the last two plastic tabs which he points out in the video. You need to study the pictures carefully to understand the correct direction to pull to release them. It's hard to get a grip in the right place. In the end I bent a small hook on the end of a piece of stiff wire and slid it between the glass and the trim so I could get a strong pull in the right direction. Just take it slowly and understand which way it wants to move to avoid breaking anything.

YouTube