Hello,

My car is a 1985 300D (W124) Euro model 6 cylinder non-turbo diesel. I recently developed a fuel leak at the injection pump from one of the fittings on top of the unit. There are six of them (one for each cylinder)......I believe these are called delivery valves? Please correct me if I am wrong. I was told that these were removable and that there are o-rings inside that need replacing. Looking at them, they have a splined portion which is used by metal brackets to hold them in place. The metal brackets are mounted to the injection pump with Torx screws. My questions are:

1) Are these fittings that go between the injection pump and metal line called delivery valves? If not, what is the correct name?
2) Can these delivery valves be removed and the o-rings be replaced? I assume that this should solve my leakage problem.
3) Are these delivery valves left or right handed threads? Any other special precautions I should take when performing this repair?
4) It also looks like I need a special wrench or socket to remove these delivery valves. Any recommendations on where I can buy one? I found a socket at this website (Tool #M0109).....Is this the correct tool?

http://www.technictool.com/merc.inj.pump-sockets.htm

I am mechanically inclined and I have worked on my own cars for years. However, all of my cars have been gas engines, and this is my first experience with a diesel. I am not familiar with the terminology of some of the part names or procedures, as this is a learning process for me at the same time! Any help/advice would greatly be appreciated!!

Thanks in advance
Alex.
bxtech@excite.com

Alex,

Take a look at this and see if it fits your situation:

http://tech-meister.com/DieselBenz/TECH/124-series/Pressure-Valve-Seal-Replacement/

If so, Hazet tool 617 589 01 09 00 *might* be the spline tool you need, not 100% sure:

http://www.samstagsales.com/mercedes.htm

There are Japanese alternatives available.

Here are some other links:

http://www.peachparts.com/shopforum/showthread.php?t=128675
http://www.peachparts.com/shopforum/showthread.php?t=83002
http://www.peachparts.com/shopforum/showthread.php?t=128096


Jack

http://www.peachparts.com/shopforum/showthread.php?t=126728

#11

Danny

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1984 300SD Turbo Diesel 150,000 miles

OBK member #23

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Thanks guys for the help and for the very informative links! All my questions were answered. I checked into the parts today and I plan to do the repair this weekend. It all depends on if I am able to obtain the special socket. The one that is on the tool list is out on loan right now. I am very thankful for these forums and for the members who make them what they are!

Thanks again, Alex.

bx what kind of diesel are you running? LSD or ULSD

i just bought the splined tool to do this job this weekend.I wasn't aware i needes the other offset socket , but i could possibly rent the splined socket to you as early as monday. I got the socket from mercedes dealer for 39$, cheapest i could find it, and they don't try to rip you a new one on shipping, actually no shipping cost for me.every where else wanted 30-50$ for the tool plus 20$ freight. P.M. me if you want the tool when i'm done.

I'm in California. I believe all the service stations here sell the S15 ULSD fuel. I'm not sure if it's true or not, but I've heard that ULSD is more damaging to seals than LSD causing them to prematurely fail.

[QUOTE=bxtech]Hello,

My car is a 1985 300D (W124) Euro model 6 cylinder non-turbo diesel. I recently developed a fuel leak at the injection pump from one of the fittings on top of the unit.

Please let us know how things work out. I have one of those IPs on my 85 but have never had to do anything but change out the vacuum stop switch. Good Luck

__________________


1985 Euro 240D 5 spd 140K
1979 240D 5 spd, 40K on engine rebuild
1994 Dodge/Cummins, 5 spd, 121K
1964 Allice Chalmers D15 tractor
2014 Kubota L3800 tractor
1964 VW bug

"Lifes too short to drive a boring car"

Thanks otto. I appreciate your generosity! However, I ended up buying a socket and I just completed the job yesterday. $39 for the socket?, that's a good price. The local dealer here says that they do not even sell the tool. I called another dealer in the next town and they quoted $52 plus one week for it to arrive. I found it in stock for $45 at an independent MBZ parts house.

As for the job, I was able to remove the injector lines with a regular 14mm wrench. I didn't need the offset crowsfoot socket. However, my car may have a different configuration than yours. I hear that you have to remove the intake manifold on some cars.

At this point, everything is installed but I can't get the car started! I was recommended: When all is completed, leave the lines at the fuel injectors about 1/2 turn loose and crank until you see fuel leaking out. The air will be bled out of the lines at that point, tighten the fittings and (whalla!!) the car should start! Not so easy. I've been cranking and I can't get fuel out of the lines! Any suggestions???

Thanks.

Actually my dog a german wirehaired pointer is otto.It would be pretty funny if i named myself "the great".haha.Did you check to see if your prefilter had fuel in it?how long did you crank it , don't let the starter get to hot though,you don't want to change that.Have you got a mityvac, some have used that to pull fuel.make sure your fuel filters are full of fuel.Please post back with results.I'm waiting for it to stop raining so i can change my seals. also did you torque and retorque to the specifications ,i believe 25 ft/lbs.I also read to do this on a warm engine because it will start mush easier.

I finally got the car started! I guess I didn't crank it long enough. I actually had to crank it for awhile! I also had to keep the pedal to the floor. It says that in one of the links (above). I think it makes a difference because I forgot about flooring the pedal the first time. It runs well and the leak is fixed!! I'm happy I got that job done! Overall, it's a relatively easy job. The hardest part was getting the parts and the special socket.

As for working on the car while it's warm for easier starting. I don't see how that could be done. First of all........It's no fun to work on a hot engine with getting burned, etc. Second, by the time you remove all the lines, plastic clips, etc., remove each valve, carefully clean everything, install the new parts, reinstall the valves/holdown plates, retorque the valves and reinstall all the lines/plastic clips.....The engine will be cooled down so much it will be equivalent to a cold start. I suppose someone could rush the job without cleaning the parts or double checking things, but you might have problems in the end. I read that everything should be cleaned, and to make sure that the valve is installed right side up. I also read on another post that a valve was accidentally installed upside down when these seals were replaced. I would recommend not rushing and to take the extra time to double check or even triple check things as they are assembled to prevent mistakes.

Anyways.........I want to thank everyone for their help and advice with this repair job. It went very well. It's been a learning experience for me as well since I've never worked on diesel cars before. Many good, friendly, and knowlegeable people here on the forum. I'm sure glad you guys are around! Thanks again! Alex.

I went through this with my 98 E300TD just this weekend. I was very frustrated with the price of the socket. I got a flange of a junker and welded it to a spark plug 13/16 socket and it worked just fine. Total cost 50 cents.

Thats A Wicked Idea!