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.

Epson Expression Premium Waste Ink Pad Replacement / Cleaning

Many expression premium printers have similar waste ink pads. Epson has 2 part numbers. First one is 1612118 and the second one is 1611102. You can always use the 1611102 in your replacements. They are often the same price and 1611102 has larger capacity.

Why Epson has two different parts? That is a matter of pricing. The smaller waste ink pad will be filled quicker and you will need to replace your printer more often. Epson has the smaller type in cheaper models, such as XP-540. At least mine had the smaller type.

Removing Waste Ink Pad Container

First you have to start by removing the two black screws holding a plastic trimpiece.

After that, you can simply lift it up and remove. You will gain access to two silver screws under it. Unfortunately I forgot to take picture of them :) The one on the right is deep inside the device so you may want to use a magnetic screwdriver head or a magnetic pickup tool.

After removing the plastic piece, you will gain access to one more screw. One was already visible. You may need to remove the paper tray completely to see it.

In this printer all the visible screws are black and others are silver colored. Once you remove these screws, you can also remove the lower cover piece.

You will gain access to one more silver screw. This screw and one under the device holds the waste ink pad container in place. The screw under the printer is shorter.

You may tilt the printer when doing this. However, ink may leak if container is too full. It should not be too full. But you never know.

The safer way is to put the printer on top a straight table and leave the container outside the table. As you can see, printer's legs are inside anyway.

You need a screwdriver to lift the plastic slightly to be able to pull the ink container down. Once the container is removed, you can clearly see the ink outlet.

Cleaning or Changing The Sponge

Normally all you need is to dry the sponges. Once they are dry, they should be able to absorb nearly as much liquid as they did originally. But you can also wash them.

One important thing to remember is to not give in to temptation of squeezing them. They will be flattened and won't work as well anymore.

The best way to clean them is simply putting them under running water until no ink comes out.

You can then dry the sponges on a heater or let them dry out outside etc. Make sure to not leave them on a surface which may absorb the ink. Because there comes out small amounts of ink even after through rinsing.

The installation is reverse of removal :) Here is the end result.

How Much Liquid Was Inside?

When I removed the ink container, first thing I did was to measure it's weight.

It weighted 148.2g then I weighted the container with washed, rinsed and dried pads again.

The weight is 61.6g. This tells me that the container was holding ~85g of liqud.

Some Experiments

I wanted to figure out if I could replace the pads with another material. The most logical choice was "magic sponge". It is super absorbent and easy to cut into shape.

 It was easy to install them to place.

The original sponge was 3.5cm high. But I used even smaller 3cm high magic sponge setting in my experiment.

First the dry weight. It was 57.2g

I have first filled the container with water, then turned it upside down until it stopped dripping. This way I could estimate how much liquid the sponge could absorb.

Wet weight 153.9g. So it managed to absorb ~95g easily. That is a pretty decent result considering I used a smaller piece of sponge.

By the way, you can literally buy 100 pieces of 10 x 6 x 2 cm sized magic sponge for less than 5euro! The container has six ~1cm thick pieces so you can use 3 sponges for 1 refill!

Below is outline of the pads (not to scale!) the last piece in the drawing is the middle part which has 3 of same pieces. Total number of pieces is 6.

The height of the smaller waste ink pad is 33mm and the container holds up to 58mm safely.

Epson 33 / 33XL Cartridge Anatomy and Refilling

Most older cartridges have strange airways and passages in them. In some ways perhaps to justify filling cartridges half full. New Epson cartridges are smaller and they do seem to have a more straightforward construction.

It is possible to carefully cut open an Epson cartridge without damaging it. One side of the cartridge is airtight and this is the side which is opened in picture below. The other side simply has another wall under it.

As can be seen easily, the cartridge has a single main chamber. There is a tight canal where the ink outlet is.

The air inlet port is very tight. The cartridge is able to keep vacuum inside. It looks like the inside volume of the cartridge is designed to shrink as the ink is used. The metal plate in middle and the spring under it ensures that inside the cartridge is always negative pressure so the ink will not flow out.

If the inside volume nears zero. The metal plate presses to a lever which opens the air inlet port in corner until it gets in some air so the negative pressure will not rise beyond a level.

I have found out that the cartridge keeps negative pressure even if it has no liquids. There must be some mechanism or membrane at the ink outlet which does not allow air or liquids to travel towards inside the cartridge.

As can be seen below, cartridge keeps the foil completely pressed in with very little volume left inside. It does NOT replenish missing content with air. The air intake valve does not allow air intake even though the spring inside the cartridge is creating negative pressure.

Refilling Epson 33 / 33XL Cartridge

Unknown to most, the green cartridge caps do not make an airtight seal around the outlet port.

The cap will tighten the bottom of the cartridge perfectly. However the little pipe in front of the cartridge outlet is connected to the inside of the cartridge.

As can be seen clearly, the pipe is connected to space between the side wall and transparent foil. The side wall has a labyrinth and a hole to outside. The labyrinth is probably to keep the dust outside. I also found out that some cartridge walls are not completely sealed at factory as I have seen them leak at arbitrary points!

This means that you can't simply make a hole anywhere on the cartridge for filling. As even with the green cap installed, the cartridge will start leaking to inside immediately as there will be no negative pressure holding the ink. The ink will flow out from the outlet and enter to the pipe. It will then travel between the transparent plastic piece and the black wall with air hole.

Before I found out about this, I have drilled few cartridges from the top and tried to fill them. The result was that the ink eventually started coming out from the side wall hole. In some cartridges the wall was not totally sealed so it started seeping through the

Refilling Option 1

As the ink will flow out from cartridge if the negative pressure is stopped. We may only fill the cartridge from bottom. The only suitable place I found for this purpose is the prism eyelet.

You must drill the eyelet very carefully as it is only 2mm away from the plastic foil. I found out that eyelet gets drilled very quickly so do not apply any pressure to the drill.

Yes, the plug covers the eyelet hole but printer simply will think that there is ink. It is possible to put the flap other way around also. I felt little resistance first but cutting the little part of the wall solved the issue. Perhaps you may find smaller plugs also.

Even the ink must obey the laws of gravity. So it won't be leaking out from the output port when it is the highest point.

However, when plugging the hole, you must squeeze the cartridge from sides to expel as much air as possible. This way once you release the cartridge, there will be little negative pressure built inside it.

Refilling Option 2

So you prefer having a hole on top? That is also possible. As usual, you need to drill very carefully as within 2mm distance is the transparent plastic cover. Just use patience and do not press the drill down at all. Let it slowly form the hole.

As the air pressure balance pipe in the outlet is the problem. We can simply block it so the ink won't be able to flow down when the inside negative pressure is lost. You can simply put a small piece of silicone sealant using a toothpick to the hole.

Yes, it would perhaps be possible to re-open the hole after filling using a needle. But what happens if we don't? Perhaps ink flows more rapidly down due to negative pressure built when it is used by the ink head? I have left the hole plugged and did not see any negative consequences yet. Actually, none of the chinese cartridges have such hole either. I am not sure what worst can happen.

Then you need to make the hole in the middle of the cartridge where the other side is connected to top solidly.

Once the green cap is on, the ink will not be able to flow down due to pressure build up at the outlet. However, you still need to squeeze cartridge when inserting the plug. So once you relese it, there will be slight negative pressure built inside the cartridge. Without any negative pressure, cartridge may leak until pressure is balanced, once the green cap is removed.

One thing to consider is that in this position the plug interferes with the metal plate inside the cartridge. However it is probably not a problem. This can be seen in my very first picture which I took from the side of the cartridge.