mtnman82

For those that want to replace their fuel filter by themselves, here you go ...

By far, the longest part of this chore for me was trying to remove the 4 funky hose clamps on the original fuel filter. The job would have only taken ~45 minutes (including jacking up the car) if it weren't for those dogs ...

Tools/materials needed:
- new fuel filter
- new hose clamps
- socket wrench w/8mm & 10mm sockets
- torx T-20 screwdriver
- jack & ramps
- trach can lid to catch gas
- pair ofr vice-grip plyers

Procedure:

1) First thing to do is to relieve the fuel pressure. On the m271, the fuel pressure relief valve is between the airbox and the engine head (right next to the oil filler cap). Pop off the spark plug cover to find it. Put a whole bunch of rags around the valve to catch the escaping gasoline (I'd wear some latex gloves too) and push down on the pin in the valve (like a bicycle tire valve) to let the gas/pressure escape. When this is done, you can put everything in the engine caompartment back together again.

2) Now you need to raise the car up on the driver's side. I used a jack and a couple ramps. I jacked the car up far enough at each corner to slide the ramp underneath.

3) Next step is to take off the driver's side belly pan which is held on with 8 - 10mm fasteners and 1 - 8mm screw near the front of the car. Slide the belly pan towards the rear of the car for final removal (after pulling away from the studs).

4) Locate the fuel filter next to the driver's rear tire. unmount the filter by unscrewing the strap holding it in (torx T-20). The top of the strap can be removed by sliding it upwards (it rests in a notch in the gas tank).

5) Once the filter is loose, remove the 4 hose clamps and pull the hoses off. Note there will be gasoline pouring out of the filter and from the tank. You will need to clamp off the hose coming from the gas tank (labelled on the filter - look at the new filter to find i.d. the hose). I used some vice-grips (not too tight, you just want to stop the gas from coming out) on the hose and a trash can lid on the ground to catch the pouring gas.

6) After old filter is removed, put new hose clamps on hoses (or use the old ones ...), install new filter (making sure the hoses are connected to the correct ports), and tighten hose clamps.

7) While the car is still up on the ramps, it is a good idea to start it up to check for leaks and remedy if necessary.

8) After checking that there are no leaks, put belly pan back on and lower car. You're done!!!

First pics: the fuel pressure relief valve, my car up on the ramps, and the belly pan off.

PS - It may take a bit of cranking to start the engine, as you've relieved all the fuel pressure and drained part of the system. Mine timed-out when cranking the first time. It might help to turn the key to the 2nd position and leave it there for a while before cranking, as I think that would get the fuel pump running and prime/pressurize the system.

mtnman82

Next pics: Fuel filter location, old fuel filter in mounted position, new/old clamps, and a close-up of these funky clamps Mercedes uses. I'm sure they're great clamps if you have the right tool to install/remove. Quite the pain otherwise ... Cheers!!!

splinter

Well done. Treat yourself to a refreshing beverage with the money you’ve saved.

mtnman82

Glyn M Ruck

Great - Thanks for pics

TemjinX2

nice write up. Couldn't you just relieve the pressure by opening the gas cap? I know on hondas i use to do this, just wondering if mercedes are different in this case.

Glyn M Ruck

Mike - now you've got me thinking. The Bosch FI system maintains ringmain pressure - but from where to where?

TemjinX2

i know from my hondas when i go to fill up when the gas tank is low. I can hear it depressurize when i take off the gas cap. I dont hear it on the c32, i figure its more subtle.

mtnman82

Good question on the gas cap vs. bleeder valve. My car sat overnight before I did this, so when I hit the bleeder valve, there was no pressure. Never touched the gas cap. Maybe someone else can tell us if/when they change their fuel filter ... Other fuel injected cars I've worked on had to have the pressure bled (i.e. taking the gas cap off wasn't enough), which is why I did it here.

C230 Sport Coup

Actually, all thats needed is one set of ramps,
put the rear of the car up, and it's not necessary to completely remove the bottom pan. Just remove a couple screws or whatever (seems like they were plastic) and prop it open with a screwdriver.

MB recommends clamping all the connections...
I didn't releave the pressure, but certainly safety glasses are called for so you don't get a gasoline shower in your eyeballs.

Great pics...I got hung up on those clips when I 1st went to do it, and
I replaced them with clamps from hardware store.

mtnman82

Just re-read and clarified (hopefully) on the clamps - thanks for pointing that out C230. I wasn't meaning 'not' to use clamps - in fact, I bought fuel injection type hose clamps to be sure they stayed on good.

C230 Sport Coup

Ha, yeh, I bought the special Fuel injection clamps, but then couldn't find them when the time came, so just bought some from the hardware store.
It took me a long time to get an answer from anyone on the forum (the other dead one) on how to get those freaky MB clamps off...
just pry 'em.

I'm coming up on time to do it the 2nd time....

Glyn M Ruck

Wise choice!

ba114

can you suggest what size hose clamps are needed as a replacement if not re-using the old ones?

bludog

Great Post. Thanks!

I just got a quote for a Fuel Filter change from MB on my '05 C240 for $250

C230 Sport Coup

Thats actually less than what many people have been quoted, since
MB feels a fuel filter should cost about $150, when a bosch one can be had for $35. And, well Bosch practically invented Fuel Injection so I imagine
it's a good product.

ATL_MB

Recently did this on both my and my wife's cars. My understanding is that this procedure is much more important now that ethanol blends are common.

GetMercedesParts.com (M-B of Annapolis) has W203 OEM fuel filters for $86.25 (vs. $115 at my local dealer).

Remove the gas cap (per M-B manual) to relieve fuel system pressure.

I use regular hose clamps and they work fine. Crimping the fuel lines is a pain -- only one line really leaks for more than a second or two -- so just have the new filter handy, and slip the one line that really leaks onto the new filter as soon as it is disconnected from the old filter.

And while I generally think that wearing safety glasses is kind of stupid - do it. Gas in the mouth tastes bad, but gas in the eye hurts like hell (I put my glasses on too late).

M-bENZ

mtnman82,

Where exactly is the fuel pressure valve in the first pics ??

Thanks,

Andy

bludog

I ordered the Bosch filter from www.autopartswarehouse.com for $40 (shipping included)

Glyn M Ruck

[QUOTE=ATL_MB;3610181] My understanding is that this procedure is much more important now that ethanol blends are common.QUOTE]

True - ethanol scrubs all the rust & crap out of the fuel tank & dumps it in the filter.

mtnman82

Sorry, I guess it's not very clear in the pic - just to the right of the oil filler cap is a schraeder type valve (it's shiney in the pic, as the black cap is off).

johnand

Thanks for the write-up mtnman82. Gettind ready to replace mine soon, and just ordered the OEM filter from RM European for $40.50 http://www.rmeuropean.com/Part-Numbe..._14601D3A.aspx , screw paying ~$100 that the stealership wants.

shopgirl32

do you guys have the part number and place where you guys pick up the replacement clamps for the hose? Thanks

mtnman82

Sorry, I don't have any part #'s for the clamps - I just got them from the local Autozone (or Kragen) store.

Javi_m16

Just had my 5 years A service done on my 2006 C230 in Germany, 300 Euro, the fuel filter alone was 100 Euro... wished I looked here before I had the service done, at least I would've bought the Bosch filter.