SL55/63/65/R230 AMG: DIY - Changing the Kompressor cooling pump on a SL55
It's extremely easy to do and requires just a little bit prep.
First, get a replacement pump. I ordered the Bosch 0 392 022 010 because of it's increased reliability vs the original pump and because it does not require any electrical adaptation.
Second, make sure you're doing the operation on a cool engine. Cooling system is extremely hot and pressurised when the engine is warm.
Third, get yourself some equipment to clamp the hose or to obturate it (or both).
Start by raise the front right wheel, you don't need more than that, everithing is located there at the front

Remove the platic protection: 5 screws, 3 large 10mm and 2 small 8mm

You have direct access to the pump

Sequency to remove the pump is as follows:
- 1) Disconnect the cables
- 2) Remove the metallic clamp, disconnect the hose from the pump. Be careful, that side is the input for the pump and you might get an undesired shower if you do not move quickly to block the flow. I used locking pliers and a champagne cork. Remember that there is also liquid in the pump and that one will fall (on you !).
- 3) Remove the 10mm bolt that holds the pumps
- 4) Now the last hose is easy to access. It's the return hose, so it should be empty at this point

The old pump, almost identical to the new one.

Only difference is behind but from what I found the absence of whole has no influence.
The old pump

The new pump

You just need to remove the pump from the ruber holder. I used a screwdriver and a little bit of WD40

We can now install the new pump following the reverse sequence:
- 1) reconnect the return hose
- 2) Fasten the 10mm bolt
- 3) Remove the cork and reconnect the hose to the pump
- 4) reconnect the cables

That's it, everything is in place

In the end I did loose only a glass of liquid which is what was in the pump.

Good luck !


