Mk7: No water through rear washer

[PT8888]

Hi guys!
Got a problem with the rear washer on my Mk7.
Fronts work fine & can hear the pump operate for both front & rear operation..... but no water out the back.
Checked the rear spoiler nozzle with a pin & not blocked.
Have also removed the front NS headlight & uncoupled the pipes. Respective pipe spurts water out when operating front / rear.
Clearly, there's a break or blockage from this coupling to the back.
Any ideas how to unblock / diagnose further??

[Bits-left-over]

Hello. Did you manage to clear the blockage?

[PT8888]

Nope! It's still blocked!
I understand it's a pig of a job because the rear spoiler has to be removed to access the pipes/nozzle?

[Bits-left-over]

I took the spoiler & high brake light off to clean all the muck out, to replace the screws & add plastic washers to protect the paintwork (threads had rotted so not much holding the spoiler on). It’s not a difficult job. I usually take photos like a tourist when I’m dismantling, so if I’ve got any of the spoiler & washer pipe, I’ll send them through. The pipe goes up the near side A-pillar & then runs across to the rear right hand corner of the roof lining. The pipe in the roof lining is glued in place so there are 2 in-line connectors to complete the run - one behind that A-pillar trim & the other is at the rear trim where the small window is. When disconnected, the roof lining pipe is close enough to the boot lid to pull it out a bit, disconnect it & aim it down towards the light cluster to avoid filling the boot. Try the rear washer.

If you’re getting water now, then it’s just the short pipe run to the washer jet that needs to be unblocked. If it’s just that, then remove it & soak in hot water with washing up liquid for half an hour & hopefully that should clear it. Probably better to take the jet off the pipe. Let me know if you want the photos.

If you’re not getting water out, I’d check the roof lining pipe & the pipe from the A-pillar to the engine bay. Unless you’re going to force water into the pipe the only way is by gravity so you’ll have to pour it in from the rear & watch for it coming out in the engine bay.

If you’re still not getting water out, then it becomes a bit more of a job because you’ll have to remove the A-pillar cover, disconnect the pipe from the in-line connector & check for blockages from there. Apologies for stating the obvious, but make sure you don’t activate the rear washer while the A-pillar pipe is disconnected as there are wiring loom connections, air bags, fuse box, etc around the area that could get soaked & ruin your day. Better to disconnect the pipe in the A-pillar from the connection in the engine bay. Then, if you can get to it, you could try blowing down the pipe to check for any blockages & do the same for the roof lining pipe. That should make it obvious where the blockage is, or hopefully, where it was.

There’s a chance that the blockage could be at the pump outlet where the A-pillar pipe connects but I don’t know about that side of the washer system. If your windscreen is getting water ok, then I would assume that the pump isn’t blocked.

Assuming you know which pipe is causing the problem, you might need to put something through the pipe to clear it. You can get very thin fibreglass rods that connect together like drain or chimney clearing rods, except these ones are quite flexible & would go down the pipe. If the blockage is in the roof lining & won’t clear, then you might have to take the lining out to get at the pipe more easily to clear the blockage, or to replace it. I imagine the A-pillar pipe will be a bit of work if you needed to replace it.

[Bits-left-over]

Just noticed your car is a 1.5 so is it from 2017 or so? I’ve based my reply on my car, which is 2009. I’m not sure if everything is the same so be careful following my advice as I might be giving you duff information.