VW Golf MK4 Rear Wiper Washer Jet Nozzle Pipe Repair

The rear wiper nozzle was rotating with the wiper arm. I had to open and see what was going on. Apparently the o-ring was broken and stuck between the washer jet pipe and the wiper pipe.

Luckily I checked the issue fairly quickly before it developed a worse problem. In many cases people realize this when the washer jet pipe is broken due to friction as it is not centered anymore without the o-ring. This causes washer fluid to leak inside the rear hatch and break latch microswitch and other things.

There is a repair kit for this purpose with part number 8L0 998 711. But it is as expensive as new motor and also fits only Valeo model as the washer jet pipe is slightly different in Bosch.

 
So, it is best to repair it before it develops a worse problem. Below is a picture of the repair kit but I did NOT use it. But it comes with 1 small o-ring and 2 large o-rings (one is not visible in the picture as it is on the wiper arm shaft already.). I don't know if the large o-rings are same size as the front wiper arm shaft o-rings. But it looks like they are probably same size.

Dissassembly And Re-assembly

Luckily there are only 2 screws and 1 panel to remove to reach the wiper motor. In this Golf MK4 Estate / Variant model. The screws are inside the handles for closing the rear hatch. (philips head screws)

Once the screws are opened, the panel can be removed by pulling out. Use some plastic opening tools and start from the middle and be patient. It is easy to break the plastic pieces on this panel, if panel is removed unevenly (eg. one side pops out with force), as the clips are really tight.

Once the panel is removed, you can access the motor. The only thing to do is to remove the electrical connector by opening the latches using a small flathead screwdriver and the washer fluid pipe by pulling out.

Normally, once the small torx screws are removed. The rear panel should come off quite easily. In my case it was very difficult to pull it out as the o-ring was stuck between pipes and it was very difficult to pull it out. I had to use some flathead screwdrivers to pry it slowly out while turning around.

Above is a picture where the pipe is partially out. Once it goes off a little bit, it is possible to remove the rear plate.

Once it is removed, and it is in good condition. You only need to clean inside the wiper arm pipe before re-installation.

I found pieces of the small o-ring inside the wiper arm pipe. The washer fluid pipe outer diameter is 3.4mm and the wiper arm pipe inner diameter is 4.7mm. I found some 3mm inner diameter (I.D.) and 1mm thickness (C.S.) o-rings from AliExpress and it seemed to be exactly same as the original. So this makes 5mm outer diameter so it fits quite snugly.

I only had half of the original o-ring but I measured it was slightly thinner than the new o-ring. Perhaps years of usage may have thinned it a bit. But when I put them on top of each other, the curve matched perfectly.

As I pulled the inner pipe quite a bit when removing. It seems like it moved a bit out from it's plastic holder. I had to warm it up using hair drier and hammer it back in gently.

As you can see, it fit slightly too long before hammering it. It should normally be flush with the outer pipe.

Here is a picture I took when inserting the o-ring in place. I simply put it on top and push it down using the washer jet nozzle. Yes, it is swimming in bearing grease.

The installation is reverse of removal. It appears there fits 2 o-rings (3 o-rings is about 0.5mm too much!). So I pushed in two o-rings so it is now double sealed. Perhaps better than new?

There is another o-ring which is on the wiper arm shaft but I did not remove it. Perhaps it would be wise to check it also once in a while.