BLACKCDI

Just an update to my original post.
I have replaced a second fuel filter since the first post. (the interval is usually 30k miles). My CDI now has 130k miles on the clock.
Some observations on a screw type hose clamps, in my experience they work just fine, after I replaced the original click type clamps(they were leaking badly) with screw type cplamps I have not had a leak for over 30k miles.
On my second fuel filter replacement at 120k miles I noticed that some of the hoses are getting worn at the ends, after checking with the dealer and finding out that each hose cost over $40 I decided to cut a small portion off the end of each hose (half an inch or less) and put them back on using (again) screw type clamps. There is enough slack in each hose so you could do this without buying all of them at $40-60 a piece.
To make sure you don't get the clamps too tight or too loose you need to purchase a right size clamps according to the hose you goona install them on.
Last 10k miles absolutley dry!
This is just my observation, I know that some people prefer to use click clamps, in my experience they leak.

brbhan

Fuel Filter Change – E320 CDI

Follow instruction below to do the job right the first time.


A picture is worth a thousand words. My thousand follows.

Tools and supplies:
-Dentist’s pick to
-ease fuel hose grip on old filter nipples; to break-the-bead in tire speak;
-R&R two O-ring seals on electronic water sensor.
-Torx T-35 and T-15 for engine shroud removal and water sensor removal.
-Hex 5mm for clamp on filter bracket.
-Few small rags to absorb fuel around filter.
-Paper towel.
-Fuel hose separator pliers optional. $10 at Harbor Freight.
-Click-R pliers, both, for removal and installation of fuel hose clamps ($23 on eBay).
-Two spare Click-R clamps, just in case! Both are different sized, stamped 86-150 & 86-125 [13mm clamp p/n 0069971890 on input; 15mm p/n 0059971990 on output line.]
Engine shroud bolts: Torque 9Nm.

Observation:
-Filter priming and system bleed is automatic with minimal manual assist.
-Filter design revisions apparently affect the way curved nipples are supported to avoid collapse: Factory-installed (Mann) filters are equipped with accessory plastic support tab. Dealer-sold revisions incorporate integral metal post to support the slimmer input nipple.
-Main filter bracket clamp (w/5mm hex screw) incorporates a spacer tab to prevent over-tightening w/possible deformation of filter body.
-New replacement filter is fitted with protective plastic plugs covering center water sensor opening as well as in/out nipple ends - to avoid fuel pump damage by contamination. Replacement filter is supplied with two replacement O-rings for water sensor plus one replacement black Bleed screw w/seal pre-installed. I would reject a purchase not protected by plugs.
-Filter has integral water separator; water is measured by sensor which is linked to dashboard diagnostics.
-At end of ‘Preparation’ below, fuel system pressure equals zero!
-For laymen, Star Service Manual Library, P/N P-2700-211-06 is sketchy.
- At job end, bench-assemble the two engine covers by sliding 3 rubber grommets of one into corresponding slots in the other. Re-install as one, large single unit for ease.

Preparation:
-Open fuel tank filler cap to ease system pressure.
-Remove BOTH engine top shroud covers. Torx T-35.
-Loosen black Bleed screw, located center of old filter (on top of water sensor) 3-4 turns until hiss is heard. Hissing subsides to sub-sonic. So, allow additional 15 minutes.



Procedure:
1. Using Click-R pliers, undo two fuel hose clamps. Pliers has one thicker jaw. Thick jaw rests on SMALL end of clamp. Holding pliers steady and vertical, squeeze handles firmly until clamp “Clicks” open. Repeat for other clamp. Note clamp position.
2. Gently pry loose these re-usable clamps, nudging each backwards on hose.
3. Use dentist’s pick around fuel hose circumference to free up first 1-2mm. Remove fuel hose with gentle twisting motion; residual fuel in hose replaces pried void, lubricating remaining hose-to-metal contact surface.
4. Prop up removed hose ends in vertical position to avoid fuel spillage. By now there is no pressure in these lines. (To prop, I used simple spring alligators, handles resting in engine crevices).
5. Remove black Bleed screw; do not discard yet. Unscrew two Torx/Star15 screws holding water sensor/electrical plug assembly.
6. Re-assemble black Bleed screw. Use it a) to rotate water sensor assembly 30 degrees to clear obstruction, and b) to yank this assembly out of old fuel filter. Shoulder of slightly loosened old black Bleed screw may be levered up w/screwdriver to coax out assembly.
Note: Sensor reaches deep. Undo clamp holding sensor wire to allow slack.
7. Replace two O-ring seals on water sensor. Wipe assembly clean, wrap in paper towel and set aside on engine block for now.
8. Loosen filter bracket clamp - 5mm hex. Lift out, discard old filter. .
9. New filter element is correctly oriented when MB logo and part number are clearly visible in filter bracket window cutout, as seen standing in front of car, facing driver. Filter top sits flush with top of bracket. Tighten 5mm hex screw.
10. Lubricate sensor O-rings w/diesel. Insert assembly, at 90 degrees to filter top, into center of filter. Affix with two original Torx screws,
11. Re-attach fuel lines and slide Click-R clamps to original position.
12. Review procedure item 1. above: reverse Click-R Plier position to ‘Click’ close the two clamps. Thicker plier jaw rests on larger end of clamp this time. Conventional screw-type substitute clamps not recommended due to likelihood of over/under tightening and diesel engine vibration concerns.
13. Replace fuel tank filler cap. Install (new) black Bleed screw. Hand-tighten only.
14. Turn ignition key to position 2 but DO NOT start engine.
15. Keeping key on position 2 for 30 seconds, loosen black Bleed screw 3-4 turns to observe steady fuel flow at orifice at top of screw.
16. Again, hand tighten bleed screw. Return ignition key to position 0. Remove all rags surrounding filter. Start car. Let run.
17. Wipe filter assembly dry. Inspect for leaks. Fuel seepage, if any, shows as accumulation on lip of filter top. S/b no leaks if done right.
18. Re-install engine top shrouds as a single unit. Align by gently fitting over oil-fill cap first. Avoid pinching lines.
19. Start an IRA Savings account. At date of this writing, dealers across the States charge $180 to $300 for this job; 3-plus shop hours for labor plus cost of lunch while awaiting car delivery!

End.

MBBLUTEK

hello, I am new to this forum. How do I access the photos? Anyone know if this fuel filter replacement procedure is different in any way for a 2008 E320?

brbhan

No pics. Hence the detail.
Procedure applies to series 211, E320 (diesel) CDI.
Check with your dealer re applicability to 2008.

crazypotato

The hoses will sometimes get stuck to the filter inserts. I just want to share a super easy way to take off both hoses from the filter inserts. Use the open end of the wrench to push the hose. PM me if you still don't get it.

ManuTheMan

Excellent article . Thanks BLACK CDI and the others for the observations. These topics make you save a lot of money, and the enthusiasts (like almost all members here) gain quite some self pride when the job's done

Just changed the diesel filter and the air filter with a friend. Perfect instructions.

cdnbacon

Thanks vm to BRBHAN. Explicit and accurate directions. I changed the fuel filter on my '06 CDI last Saturday and it was fairly easy. It would have been easier with the CLIC-R tool which I will buy since jerry rigging my tool set was not optimal. And cost me some time. I did the 26k mile service since I needed a baseline to start from as I have only had the car since June'10 and bought it with 22k miles on it and it now sits at 26k.
The information everyone supplies gives me much more confidence to DIY.
I have an aversion to paying a boutique dealership exhorbitant prices for such easy work. We are blessed with local MB garages who compete very well pricewise with the big dealerships and one in particular I used for an oil change - when they got it on the lift and took off the under covers they discovered a transmission leak which they fixed on the spot. It's a common problem with the CDI so it would be advisable to occasionally check the underside for potential problems.

brbhan

Glad it worked for you.

The common tranny leak s/b covered under MB warranty. Also, watch for an oil drip at turbo intake pipe. Location: accessed from below, this silver colored pipe sits between rad and engine. Oil drops are visible where pipe curves at its lowest point closest to front under-engine cover. That too is a warranty item and can get bad and expensive if not addressed. Mine occurred around 25Kmi. Dealer eventually fixed after three visits. New pipe and ancillary parts.

connecticutcdi

I'm having trouble removing the sensor at the stop, does it just pull straight out. I tried using needle nose pliers. Did you use any tools i.e. flat screw driver?

brbhan

Att: connectucutcdi
Read and re-read steps 5 & 6 in my original post.

Since I do not know whether or not you worked on the torx screws holding the assembly, I'd hate to misguide. Be as detailed as possible, should you have additional questions.

brbhan

An afterthought about screw-type clamps: Initially, they're OK. However, they stay put in one single position, necessitating periodic tightening to fix leaks opver time.

On the other hand, hoses will either swell or shrink. Click-r clamps self adjust to accommodate such dimensional changes. When diesel leaks, the leak is replaced with air. Diesels hate air in the system.

cannonec

Where do you get the female (outside) torx sockets or wrenches?
I have male socket set (looks like allen wrenches).

brbhan

Sears Roebuck has a specialized 'Tools' division. Store salesperson should be able to assist. www.HarborFreight.com is another source. For the latter, look for coupons on the web and coupons inside magazines such as the Family Handyman. Frankly, tho' I cannot recall ever having the need for the tubular type. Then, again, I hardly use the CDI - in favor of the SDL.

Oh, last not least, check out eBay. I am surprised at the availability of specialized tools - which is where I picked up the special pliers for the fuel filter job.

Good luck!

nadimramzan

Hi... I have E 320 CDi, year 2000, UK model, does my car have something similar to bleed the air out of the system. My car is also having starting problems. If its been standing all night, it wont start after the first key turn. After the first key turn, you have to leave it 5 mins, then crank, and it starts. Just had a full service, battery is ok, glow plugs have been replaced, and injector seals done. One of the clear fuel lines from the pump has a bubble around 3/4 inch. Any help would be appreciated. thanks

brbhan

Greetings, Ramzan Sahib:

The CDI fuel filter, to my knowledge, comes in two flavors (note: US spelling , the two being a) WITH and b) withOUT a water separator built into the filter. The water separator setup involves an electronic sensor that plugs/screws into the center of the filter and is visibly connected to an electrical wire that feeds data to the CPU. The bleeding mechanism is integral to this setup in that a center screw, when loosened, allows air to escape.

Bottom line: If you observe an electrical line hooked to the filter assembly your question regarding ''....something similar to bleed......" is answered.
BTW: All MB diesels thru' the decades, to my knowledge, have utilized the 'Center Screw Above Filter' for bleeding purposes. The CDI continues in that tradition. The old saying: If it works, why fix it.

A diesel motor is set up to self-bleed. The bleed screw merely hastens the process. Self-Bleed = there are two fuel lines, one feeding the pump and cylinders, the other is a return line. When the engine turns, any air introduced during servicing is returned to the fuel tank and eliminated from the circuit. This is exactly what is happening in your case; the initial engine revs fail to fire up - are engaged in eliminating air introduced to the system through leaks over-night. This done, the engine finally fires.

For proper operation the diesel fuel system MUST NOT have any leaks. When fuel escapes, air replaces the void. You must have an uninterrupted fuel stream from the tank, right up to the cylinder. Cradle to grave concept.

Newer formulations of low sulphur diesel fuel, it is claimed, expedites deterioration of rubber hoses so they may need to be changed oftener - say, every five years (as compared with older models) to be safe. Serious fuel system air leaks cause knocking sounds as you drive.

Reading your msg it is evident you have diagnosed your problem yourself!

Solution: Look for fuel leaks. Park over newspaper over-night. Slide under the car with a flashlight and look for moisture. Patiently, do it yourself. Mechanics do not make much money on such trivial matters.
That is my modus operandi. Hope this helps.

nadimramzan

thanks, will check. Was also going to check the small pipes running across the injectors, because they seemed quite loose.




regards

Gifu

reviving an old thread...
question: is there a prefilter in the tank? A "sock" as it is sometimes called?
Previous owner mentioned that dealer replaces transmission due to "hesitation", but problem persisted (Ha). Problem turned out to be "filter in the tank". My diesel land cruiser had this, and I found it clogged.

(I don't have any hesitation, I'm just curious if others have found, changed, cleaned the sock on a CDI)

ot1

Earlier in this post it was mentioned the the oem click clamps could rust. The two click clamps I got from the dealer cost $4.25 total and they are stailness steel unlike most little screw type hose clamps from china made of some crap steel And they can tear up the hose too. What a mess it would be if one of those cheap hose clamps failed.