This DIY describes the process of removing the washer reservoir in an R171 SLK.
I am doing this right now because I am getting ready to install an aftermarket fender which will not leave enough room for the washer reservoir to be installed. After the fender install is completely I am going to figure out some other solution for the reservoir but that is a separate future thread
.
This DIY is useful for people that want to replace their washer bottle perhaps because it has started leaking, or need to replace one of the pumps or perhaps the fluid sensor.
I hope it will prove useful to someone.
STEP 1: WHEEL REMOVAL
The first step is to remove the front wheel on the right-hand side of the car. There might be a separate DIY for this step. Basically slightly loosen the 5 lugnuts. Then jack up the car. Unscrew the lugnuts the rest of the way, the remove. Take off the wheel.
At this point it would be a good idea to place a stack of wood under the central jackpoint in the middle of the engine block in case the car slips off the jack. I use the cheesy jack that comes with the car, and it is not the most sturdy thing, so if you're using this, please be safe and make sure you have a backup measure in place in case the jack decides to slip.
STEP 2: REAR FENDER LINER REMOVAL
After you remove the wheel things will look somewhat like this:
![Image]()
We'll now remove the rear section of the fender liner, by first undoing 1 10mm screw and 5 10mm plastic nuts, indicated in the picture. Two of the nuts are behind the shock in approximately the locations indicated with circles.
Next we need to remove 1 8mm screw and 3 expansion clips from the bottom of the car, before we can remove the fender liner. They are indicated in the following picture.
![Image]()
One of the expansion clips is a bit recessed and cannot be seen directly in the pic, but I've indicated its location with a circle. The expansion clips are of the type where the center section does not fully come out, but just retracts. I use a small screwdriver to pry the center section out a little bit, then grab it with needle-nose pliers to get it out the rest of the way.
Now you can carefully pull the fender liner out. Do not pull too hard if you have the car jacked up on the OEM jack, because too much lateral movement might cause the car to slip off.
This are pictures showing the hardware that we've just removed (minus the 10mm screw which is missing on my car), and the fender liner itself.
![Image]()
![Image]()
The washer bottle is now visible in the space behind the fender liner. As you can see it's a tight fit in there. You cannot even put your hand in between the bottle and the fender itself.
The bottle is held in place by two friction couplings on the back and bottom of it, and by a single 10mm nut indicated in the picture. Note that there's no point undoing the screw now because we need to remove all the pumps, hoses and electrical connections first.
![Image]()
STEP 3: REMOVING WASHER BOTTLE HARDWARE
First we need to remove the refill funnel which is reachable through the engine compartment. Undo the expansion clip holding the funnel opening in place, then simply pull the funnel up and to the right (towards the middle of the engine compartment). It will come loose. If your washer bottle is very full, some of the fluid will escape at this point.
![Image]()
This is what the funnel looks like after you've pulled it out.
![Image]()
Now let's take a closer look at all the hardware hooked up to the bottle itself.
![Image]()
To the left is the supply line, pump and electrical wiring for the Bi-Xenon headlight washers. If you don't have this option, this slot will be empty.
Next to it is the supply line, pump and electrical wiring for the windshield washers. Both of the pumps are held in place by a black plastic bracket.
On the inside of the bottle is a third electrical connection for the fluid level sensor. There is a 4th connector visible in my picture which is kind of taped to the wire that goes to the fluid level sensor, but this one is terminated in my car. So this is presumably for some option that I do not have, perhaps the washer heater.
![Image]()
Undo the fluid level sensor connector, and pull on the right of the plastic bracket to undo that side. It might look like it's glued on or something but as the picture shows there is a little button which holds it in place.
Next we'll pull up on the pump for the windshield washer to undo it. Note that when you do this, the entire bottle will empty out as you can see in my picture. So if you don't want 7 liters of liquid on your garage floor, you should put something underneath to catch it.
![Image]()
I am doing this right now because I am getting ready to install an aftermarket fender which will not leave enough room for the washer reservoir to be installed. After the fender install is completely I am going to figure out some other solution for the reservoir but that is a separate future thread
. This DIY is useful for people that want to replace their washer bottle perhaps because it has started leaking, or need to replace one of the pumps or perhaps the fluid sensor.
I hope it will prove useful to someone.
STEP 1: WHEEL REMOVAL
The first step is to remove the front wheel on the right-hand side of the car. There might be a separate DIY for this step. Basically slightly loosen the 5 lugnuts. Then jack up the car. Unscrew the lugnuts the rest of the way, the remove. Take off the wheel.
At this point it would be a good idea to place a stack of wood under the central jackpoint in the middle of the engine block in case the car slips off the jack. I use the cheesy jack that comes with the car, and it is not the most sturdy thing, so if you're using this, please be safe and make sure you have a backup measure in place in case the jack decides to slip.
STEP 2: REAR FENDER LINER REMOVAL
After you remove the wheel things will look somewhat like this:
We'll now remove the rear section of the fender liner, by first undoing 1 10mm screw and 5 10mm plastic nuts, indicated in the picture. Two of the nuts are behind the shock in approximately the locations indicated with circles.
Next we need to remove 1 8mm screw and 3 expansion clips from the bottom of the car, before we can remove the fender liner. They are indicated in the following picture.
One of the expansion clips is a bit recessed and cannot be seen directly in the pic, but I've indicated its location with a circle. The expansion clips are of the type where the center section does not fully come out, but just retracts. I use a small screwdriver to pry the center section out a little bit, then grab it with needle-nose pliers to get it out the rest of the way.
Now you can carefully pull the fender liner out. Do not pull too hard if you have the car jacked up on the OEM jack, because too much lateral movement might cause the car to slip off.
This are pictures showing the hardware that we've just removed (minus the 10mm screw which is missing on my car), and the fender liner itself.
The washer bottle is now visible in the space behind the fender liner. As you can see it's a tight fit in there. You cannot even put your hand in between the bottle and the fender itself.
The bottle is held in place by two friction couplings on the back and bottom of it, and by a single 10mm nut indicated in the picture. Note that there's no point undoing the screw now because we need to remove all the pumps, hoses and electrical connections first.
STEP 3: REMOVING WASHER BOTTLE HARDWARE
First we need to remove the refill funnel which is reachable through the engine compartment. Undo the expansion clip holding the funnel opening in place, then simply pull the funnel up and to the right (towards the middle of the engine compartment). It will come loose. If your washer bottle is very full, some of the fluid will escape at this point.
This is what the funnel looks like after you've pulled it out.
Now let's take a closer look at all the hardware hooked up to the bottle itself.
To the left is the supply line, pump and electrical wiring for the Bi-Xenon headlight washers. If you don't have this option, this slot will be empty.
Next to it is the supply line, pump and electrical wiring for the windshield washers. Both of the pumps are held in place by a black plastic bracket.
On the inside of the bottle is a third electrical connection for the fluid level sensor. There is a 4th connector visible in my picture which is kind of taped to the wire that goes to the fluid level sensor, but this one is terminated in my car. So this is presumably for some option that I do not have, perhaps the washer heater.
Undo the fluid level sensor connector, and pull on the right of the plastic bracket to undo that side. It might look like it's glued on or something but as the picture shows there is a little button which holds it in place.
Next we'll pull up on the pump for the windshield washer to undo it. Note that when you do this, the entire bottle will empty out as you can see in my picture. So if you don't want 7 liters of liquid on your garage floor, you should put something underneath to catch it.
