Domm

Hey everyone,

So my Mercedes is approaching 39,000 miles and I have read many threads stating that it's highly recommended to perform a transmission fluid flush because many people have had early transmission failures in the 722.9 transmission.

I've looked through a few DIYs in performing this flush and some say that the transmission is completely sealed in, we need a $3,000 machine to flush it, we can perform the service by dropping the pan and changing the filter, and some Mercedes don't have a filler cap.

I'm new to Mercedes and the different models, but I have serviced a few other cars (none as picky as a Mercedes) and I am trying to get a specific answer. Some threads (by john) mention that we can perform the transmission flush just as the W203, but there isn't a filler cap in the W204 (not sure about this) and some require the STAR system to do it. Someone else mentioned that we could use pump the transmission fluid using a pump they purchased on amazon.

My question is that can we perform a transmission fluid flush in the W204 ourselves without the use of expensive equipment? Because if we can't, i'm just going to take the Mercedes to the dealership for this service since it apparently only needs to be done once. Sorry if this has been discussed before and I didn't see it. I just need clarification because I'm confused by the different threads because none of them are under the W204 section and I'm unsure if it's the same process.

Domm

Nevermind -_-' I get it now after looking through the DIY again. Sorry for the stupid question lol

SuPER__S

I did my first trans flush at 50K. I took it to the dealership cost me $300. Didn't want to deal with it.

The way they measure the fluid level is by a laser at a certain temp. I just didn't want to mess with all that headache so stealership it goes.. LOL

Glyn M Ruck

Presume you found this.

https://mbworld.org/forums/clk-class...ce-thread.html

Domm

Yeah thats what I feel as well, but I plan on keeping this Mercedes well past 100k miles. I'm torn between taking this to the so called "stealership" to avoid this meticulous process, but I also feel that learning to do this myself will prove extremely beneficial in the future at the risk of making a mistake. I think I'm leaning more towards performing this procedure myself because, well, I just like working on my own cars. Pride of ownership

Yeah. Well, I found this article before but I guess I needed a few minutes to let the information soak in before I understood everything. The DIY isn't confusing at all. I don't know why I didn't understand it.

Hieronymus

By the way, which are Manufacturer and OEM Part Numbers for fluid filter to newer versions of 722.9 transmission (which uses ATF, Specification 236.15 for fluid) ?

domwild

There is even a sticky for the 722.9 auto trans service. Got myself a $25 12V pump and an auto gear box dip stick ($25, $75 ex Merc) ex Hong Kong, broke the red seal of the filler tube, stuck it into the filler tube at the back fire wall and pumped it out. Measure quantity pumped out. Crawled under car to take sump off, read DIY instructions. Changed seal and filter, cleaned pan and magnet, add oil from pan to measure total taken out. Replace pan. Get torque figures ex DIY Facebook videos.

My oil was black and stank at 120,000km as two separate Merc dealers did not change the oil (and fuel filter!) at the recommended 60,000km, sad! Excuse: Customer did not want it?? So a client puts his car in for service and is then asked, do you want a service?

Repeatedly pump out and refill. Get laser temp gizmo to read level at 80 deg via dip stick while running in Park. My DIY here is not extensive enough, so read everything you can get your hands on, forget the "Filled for life" bull..... It is recommended not to get the colour back to perfect red as it may "shock the transmission" or loosen too much gunk I suspect. One DIY chap even recommends a trick to indicate to the electronics that the oil has been changed, but I am not game enough at the moment to do so.

Merc sells expensive oil which I used, but if you read the Merc oil speci, they allow lots of cheaper equivalents, like Fuchs, etc. .

NZ-Merc

Yes done mine at home no expensive tools required.
First step is by the dip stick mentioned above, measure the oil level with the old fluid first hot and cold write the numbers down... this part is important so when you are finished the oil level is same as when you started.

Remove the oil pan drain plug and let the fluid flow in to a larger oil drain container situated under the trans sump, then remove the trans sump pan.

Remove the plastic/rubber cover below the torque converter and have some oner slowly rotate the crankshaft with a socket and ratchet until you see the drain plug, remove and drain aprox 2.5 liners of oil from the converter.

Install converter drain plug and cover.

Change out the trans filter and give the sump and valve bodie a wipe down, mine was really dirty with a coating of grey/black film.

Install new trans pan gasket and assemble, I reused the trans bolts.

Now measure up the qty of old oil and tip similar amount new oil back in.

Start the engine manual move the shift leaver through the gears back in to park let it idle the turn off for 10 minutes min.

The reason turn off is to let and oil drain back out of the dipstick tube after you have filled through the tube new oil - so after waiting you get an accurate reading of oil level when you restart it.

Top up oil level until correct hot/ cold levels achieved same as level before you started.

Through wash down remove all oil residue, then test drive and recheck level.

In my W204 C200k I used Fuchs Titan ATF 4134 fluid and needed 2 x4L containers.
Dave

domwild

Thanks NZ Merc for that, great! Mine is a C220 CDI W204.008 646 engine 2007 model, but I have not found out yet if it is a 722.9 or 722.6 box, in other words 5 or 7 speed gear box. Your trick with emptying the torque converter I will have to investigate if you tell me which model box yours is, so I am sure we both have the same.

There is a rumour, that flushing the system thoroughly like you have done with emptying the torque converter is "shocking the system" as too much gunk has been loosened, what do you think?

Another suggestion is to also replace the unit (socket) which takes the electrics into the box as those O-rings may leak oil into the electronics. That after-market part is cheap anyway.

JettaRed

iTrader: (1)

Holy cow! You don’t know if you have 5 or 7 speeds, or did I misunderstand? If that’s the case, then take it to the dealer. While this can be easily done with the right equipment, tools, and knowledge, it’s not something to guess at.

A very good good source for what you need is www.fcpeuro.com if you’re in the US. They will sell you a kit for your car. By the way, avoid “flushing” the tranny; just drain and fill.

domwild

Thanks JettaRed. Sorry, at my age I am easily confused. When I read the 722.9 sticky, I realised mine must be a 722.6 box. I am sure I do not have that easy access to the torque converter by turning the crank to get at the drain plug and getting those extra 2.5 litres out of the torque converter plus pushing an overflow pipe in, that is all 722.9 stuff.

You will find that for the 722.6 box, being unable to get the oil out of the torque converter for me as a DIY person meant repeatedly draining/filling with a 12V pump through the dip stick tube. Some stealerships do it via a flushing machine and that process uses much more than the recommended 7.5 (?) litres of oil. Perhaps it also needs a 722.6 sticky here and if I find a reference, I shall pass it onto the moderator.

JettaRed

iTrader: (1)

Well, if you have a dipstick tube, then you have the 722.6. That's actually very good since you can replace the conductor plate if you ever need to without having to get the tranny reprogrammed. Search YouTube for videos on how to drain and fill your tranny, which will be MUCH easier than with the 722.9. Still, run your VIN through www.DataMB.com and let us know what the transmission number is.