A mate and I changed the supercharger oil tonight and discovered some things that may help others when changing their oil.

PREPARATION
First if you are changing your oil make sure you read the DIY from kjlindgr as this seems to be the most straight forward advice on the subject. Apart from this there seems to be some confusion and much misinformation on the net regarding the amount of oil that should be replaced with most other people suggesting to replace the same amount of oil that has been removed. This assumes there to be no change in the oil level as the oil deteriorates which appears to be incorrect. It is evident the oil must either evaporate or change in volume since almost everyone has different readings. We managed to extract less than 125ml but replaced probably between 200-300ml (maybe more) before oil began trickling from the drain plug where the extraction/filling takes place. Make sure you have at least paper below the drain plug with rags ready to soak up any excess spillage. Again read the DIY from kjlindgr for an explanation.

EXTRACTION
The most popular method suggested is extraction with a syringe but not having a syringe handy we had to consider alternatives and surely there were better? Plan A involved a fish pump but turns out all were in use so Plan B sprung into action...

First we found 2 x 3 foot lengths of clear hose, a jar, a bicycle pump and a vacuum gauge. Switched the valve in the pump upside down so it sucked instead of blew and connected the gauge. We then connected both hoses to the lid of the jar and ran one to the pump and the other into the drain plug of the supercharger. With one person pumping to create a vacuum in the jar another poked around looking for oil.

Turns out that looking for oil wasn't as easy as we imagined! After a poor start poking around semi-aimlessly, extracting only a small stream of drops with each pump we decided to pursue a more controlled extraction method. Inserting a foot long thin wire into the hose did the trick and once bent appropriately allowed precise manipulation of the sucking hose into all the nooks and crannies that the crusty oil might be hiding.


extracting oil from the supercharger via pump

REFILLING
To refill the supercharger the valve on the pump was switched back to its correct position and now connected relatively airtight directly to the can of Jet Oil II instead of the jar so the new oil was “pumped” in rather than “sucked” out. Essentially everything in reverse.


replacing with new jet oil II via hand pump

This is one of those jobs that most people let slide by but considering how low most people seem to find their oil and with the high price of a supercharger it's definitely worth some preventative maintenance.

 

nice write up sir!

 

what is the size of the damn small allen key

thank you

 

its a number 5

 

great !!!! thank's !!!

 

Hi

Thanks for the write up...well done.

Regards,

OZZYAMG

 

What did you think of the smell?

 

Actually not nearly as bad as I was led to believe. Smelt like lanolin. I've owned the car for 12 months so unsure if the previous owner had changed the SC oil although it looked pretty bad like it needed changing and the level was low from what I could tell. Hmm maybe my nose isn't easily offended but I wouldn't have guessed that...

 

A "ball head" 5 will make the job easier.

 

Contact cement on the ball head when you put it back in keeps it from dropping.

 

My bad, answer written in haste.... Ball Head #5 is correct for 10 points!

 

job done !!!

thank you all for the great info !!!

 

I saw mentioned a 5mm hose, is that ID or OD?

 

before i make a thread does anyone here know why my car is shooting oil from the pulley on the inside of the hood? it started happening ever since the supercharger oil was changed... could it be overfilled?

 

maybe.... did you put back the same quantity you took out or more ?

 

I'm not sure which 5mm hose you are referring to but if it's to fit into the drain plug then definitely OD.

 

Changed my 2003 cl55 oil today. After carefully probing the nooks only 30cc was removed.
The odor is a lot like the cadaver lab. A combo of dead and formaldehyde .

150 cc of jet oil back in before a slight return from the drain hole.

This was quick and easy maintenance that I'm glad I did.

Why does Mercedes not recommend this work?
It would be easy cash.

 

At the time Mercedes put too much faith in the longevity of the oil. Initially inferring the supercharger was a maintenance free part for the length of its life the lowly oil turned out to be its achilles heel. Turns out that lubricating parts which are spinning at tens of thousands of revs took its toll over the years and "did" actually change the oils structure, effectiveness and volume.

Considering some of the low oil extractions coming out now I don't think it will be long before we see a few issues as unwitting 55 owners run low on sc oil.

 

My guess is overfull. Mine is filled to the plug with the SC level and doesn't leak, but I had it nose down putting rear K-mac bushings in and found some drips on the floor. I had changed the oil 3 times and still recognized the smell of those drips.

 

Mine was filled when my supercharger was off. A tech at the dealer did it

 

The other DIY thread is what I'm referring to I believe. Someone there mentioned using a 5mm hose but did not specify ID or OD. The smallest OD hose I could find on amazon was a 8mm OD line. Do you know if that would work?
I wonder if that tech had the drain hole tipped upwards and put too much oil in it.

 

I dont know but its been a pain in the a$$ having to put tape on top of the hood so the oil doesnt shoot on the hood it self because that oil does not come off what ever you do to it, buff wax w.e it will never come off. I am going to try and reach him and see wtf he did

 

Maybe the bearing was on its way out and only became a problem once oil was refilled back to the correct level? It's a fairly straight forward procedure to change the bearing.

 

i just had the pulley replaced... one of its springs was bad so the bearings and the pulley is new. so far so good but i always keep my eye on it.

 

I'd be chasing up the tech who did the work. Find out exactly how much oil was replaced - beyond that I'm stumped...