300SDL Inj Pump Bottom Seal Leaking
 

I have a 87 300SDL and the bottom seal/gasket on the injection pump is leaking oil.
Causing it to pool up in the cavity of the motor mount bracket.

Has any one changed this seal while the pump was still mounted?

I've done a couple
 

Not too bad a job really. The little torx bolts next to the block are tight. I took a 1/4" drive torx (I do not remember the number right now), cut it down to fit in a ratchet wrench, and had no problem after that. Warning, it does make a bit of a mess when the bottom plate comes off. Old seal on both of them just fell apart. Replacement part does not look like the parts diagram as it is round, but fits just right.

Good luck

Bill

After replacing 2 seals in my SDL's IP the leaks kept coming so I pulled the IP to replace all the seals.

Sixto
95 S420
87 300SDL

fyi: Preliminary assessments indicate that the o-ring for the top of the oil filter on an OM617 is a suitable replacement for the IP bottom plate on an OM603--in case locating the correct seal is difficult, otherwise go with stock.

Mine leaks a bit from that seal as well. It looks like you can get the cover off with the pump still mounted. It will be tight but seems do able.

I plan on getting my IP rebuilt this winter so for now I will just ignore the leak, it is pretty minor anyway.

__________________
H2O2 fyi: Preliminary assessments indicate that the o-ring for the top of the oil filter on an OM617 is a suitable replacement for the IP bottom plate on an OM603--in case locating the correct seal is difficult, otherwise go with stock.

So I take a round seal/gasket/o-ring and forum it in to a rectangle and try to hold this shape while I try to mount the cover with six screws.
Sounds like a nasty job really. Definitely will look at the price between seal & O-ring. I do have that style oil O-ring.

Had mine done 2 weeks ago, but top seals were cause
 

Same symptoms, noticed left mount was cleaner than usual, but it was less than 1 year old, so thought it was still clean from newness. Checked closer when I noticed a fuel odor and could see dripping off bottom of pump when engine running. But... turned out to be 2 top seals on injector lines leaking a barely noticeable sheen across the top surface, down the side and dripping off the bottom. When wiping off the top quickly, you could spot the sheen reforming if the light was right. I took to the local Bosch shop since I did not have the splined socket (or any other tools yet here)

I've installed that o-ring on a spare pump sitting on my bench, but I've never determined 100% whether it will seal properly. It installs by slipping over the rectangular ridge on the bottom plate and conforms to that shape rather easily.

I wonder if I'm the only one, but my lift pump gasket is leaking. Do any of you have leaks there? Because I wonder if that's what causes the bottom cover to leak or maybe it's just the diesel fuel cleaning up?

Thanks
David

I am in the process of replacing the orings and seal (93 300D 2.5L)l eaking just below the spline nut on the IP. Only No 1 is leaking, but I am going to replace all 5.

The orings and seals r dealer items. The orings look different than anything I have seen.

I have the manifold and fuel lines off yesterday. Started the job at 5 pm.

While in there, I also will be replacing the glow plugs and the last fuel line from fuel filter to back side of IP.

The following was forwarded to me by Sixto.

Originally Posted by gsxr
Here's what the TDM says, word for word:

To obtain a correct seat of delivery valve holder sealing rings, tighten delivery valve holder to 30Nm and release, tighten once again to 30Nm and release again, then finally tighten to 30+5 Nm. Excessive tightening may cause a leak on elements at low and high pressure end by distortion of injection pump housing.

Interprest as you wish...

You read my mind on the torque values, was just going to ask.

Well I received my dealer seals for the inj bottom of the pump.
I tried to use one of my t-25 bits to undo the bolts but it felt real sloppy
and none of the other sizes would fit.
Do they make special bits that are metric? Or is my set just a cheapy?

I also installed new Blistens on the front and the inside bolts were a pain
to unbolt and bolt, my 10mm socket would not fit because of the angel of the
shock.Used a box 10mm wrench with very little turning motions.

I recently found out that the fastener that I though was a Torx is actually a 12 point metric fastener. I'll bet the injection pump requires a 12 point metric bit, as well.

The trick for the shocks, which I also found out after the fact, is to compress the piston rod and rotate the shock outward as far as possible. Then the innser screw is readily accessible and you don't need to spend 30 minutes trying to get the damn thing to start and turn 10 times. ;)

Tri square or Triple square bits
 

I did use torx to do the ones I replaced, but I would have used tri or triple square bits if I would have had a set that went that small. I concure that they are probably the "correct" tool for the job..

Bill

Help - some idea on removing ONE LAST screw
 

I tried to change out the bottom seal on one of my 300SDL project car and I ran into problem and need some ideas. I need to remove the bottom 6 screws on the IP to change out the seal with the IP in the engine. I removed the small fuel heater and its holdig plate over the engine mount to give me more room to access the screw heads. I have the correct T30 torx bit and I managed to remove 5 screws but NOT the inside right hand corner one. That one is a pain to get to and the screw head seems to be slipping. I do not think I damaged it myself, probably was done by others.

I use this right angle screw driver to remove the screws as there is limited room.

http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=92630

I am at my wits end as to how to remove the last screw. I can put everything back together and put up with the oil leak but I dearly want to replace it. Any ideas on this one. Removing the IP is out of the question.

That's the only safe way to do it at this point. You'll only damage the screw further if you can't see it.

Questions on 300SDL IP?
 

I may not tackle this job but just want to ask a dump question.

I failed miserably to remove the last screw in the far RH corner. I put a small tray underneath the IP with some rag and it seems to be collecting all the oil. However, I am considering taking out the IP as I bought the o-ring and I may as well put it to good use.

Say, if I mark the IP pump relative to the engine block and re-install it in the SAME place, do I need to set the timing again? Can I screw up? I have done gas engine timing but I am not sure whether I can handle the 603 engine.

Any advice is welcome.

As long as the IP is locked when you remove it and remains locked until you install it, there's no need to mark the block. Mind that you install the IP such that the bolts are in the middle of their slots so you have the maximum range of adjustment in both directions.

[edit] You'll reduce the number of variables if the timer remains engaged with the timing chain.

You can eyeball IP timing easily with an IP lock. It's not more difficult that timing a gasser distributor, just a ton heavier :) You can rent an A-B timing light in the tool rental forum which you might as well do to remove the doubt.

Sixto
87 300D

What do you mean by locking it? I am a novice on diesel engine and IP.

Thanks Sixto.

On the driver side of the IP, there's a service port capped by a plug that takes a 17mm wrench. When you remove the plug, a couple of teaspoons of engine oil will drip out, and it should look something like this -

http://www.w124performance.com/image...__RIV_tang.jpg

The flat screwdriverlike tip you see will be centered in the port when the IP is at the reference position which corresponds to a crank pulley position of 14* ATDC #1. That's where it would have been set at the factory. It will shift because of chain wear, replacing the head and gasket, etc.

The locking tool looks like this -

http://www.w124performance.com/image..._lock_tool.jpg

The lock threads in place of the plug and the slot at the far end engages the tang visible through the port. With the lock in place, the IP driveshaft cannot move relative the IP case so IP timing is preserved when removing/installing the IP.

[edit] Pictures from the gsxr collection.

Sixto
87 300D

Great pictures, thanks

I had the same leak from the bottom plate on my son's 87 300SDL. New seal from the dealer was $13. We had couldn't get the torx screws out so we just removed the IP put in a new bottom plate seal and all new o-rings at the same time. Popped it back in and fired it up. No leaks, no problems.
We wasted an entire day trying to get those torx screws out without removing the IP. Somebody had striped a head before us. Way less trouble to just pull the IP and 'git-er-done'.

W126 Diesel Injection Pump bottom seal replacement
 

I just completed this task on a 1987 300SDL and YES, it can be done without removing the IP (injection pump) from the vehicle. If I must stress ONE point, it is PATIENCE!

You DO NOT want to trash the Torx (T-30) heads of the six (6) screws (M6-1.0 pitch) x 12mm length holding the bottom cover in place.
My tools of choice were a 1/4" socket driver, an assortment of 1/4" diver extensions, a T-30 Torx driver bit, a flexible 1/4" driver extension and a (Sears Craftsman) 1/4" x 1/4" flexible socket. The T-30 Torx bit inserted into the 1/4" flex socket just barely yielded enough room to get a sufficient purchase (bite) on the Torx head screws to loosen them. As one member suggested in this thread, cutting down (shortening) the Torx driver bit will increase your ability to get a good grip on the screw heads. Since driver bits are usually made of hardened tool steel, it is usually necessary to grind the bit down with a grinder.

I found it helpful to remove the clamping bracket which supports the two hard lines to and from the oil cooler. This gives you a bit more room to maneuver in.

Make sure the Torx head recesses are clean and free of dirt so the driver bit will seat to the bottom of the recess. I used spray brake cleaner with an extension nozzle, a tooth brush and q-tips to get them squeaky clean!

Take your time! Take your time! Take your time! Be sure to have a GOOD grip on the screw head before you attempt to loosen it. BTW, this is not a real messy job if you do it after an oil change and before restarting the vehicle. The amount of remaining oil in the injection pump is not that much.

Once you have all 6 (six) screws loosened, it is not difficult to remove them. Clean the bottom of the injection pump thoroughly and the sheet metal cover as well. You are now ready to install the cover with a new seal ring (A 004 997 46 40). Usually, one wets (lubricates) the new seal ring with a bit of fluid (oil). However, doing so in this case will cause the new seal (i.e. big square cross-section o-ring) to slip off the cover or twist before you can snug the cover in place. I opted to fit the new seal dry, though I did consider a few drops of super glue to hold it in place on the cover plate.

If you are suspect about the condition of the screws you removed I would NOT waste time to visit the dealer in an attempt to get new ones. Rather, find a local fuel injection pump re-builder, one that handles Bosch injection pumps; he will have them and should only set you back about $8. Other alternatives are to use socket head hex screws (M6 x 1.0 x 12mm - 5mm allen wrench) or even better, flange screws/bolts (same M6 x 1.0 x 12mm - 10mm flexible socket driver). Just be certain the screws of your choice are at least grade 8.8 (minimum). I purchased new Torx head screws but opted to use flange bolts because of the larger bearing area of the flange head. I purchased a Sears Craftsman 1/4" drive x 10mm flexible socket driver for this purpose.

There is enough room under and around the injection pump so that you should be able to fit the cover and hold it in place while you install two (2) screws by hand to hold it in place. Then it's under the car to install the remaining screws and snug them down EVENLY. Put a rag under the injection pump (just in case), fire the beast up and check for leaks.
Hopefully, you are good to go for another 23 years.

Update on the leak.
 

This job has been dormant for a year. I just put a rag under it to soak up the oil. Managed to remove the last screw and replaced the seal. To remove the last screw, I used a saw blade and cut a slot on the bolt head. It was not easy as the access is difficult since the IP was in situ. I then used a flat blade bit to remove the bolt. So it is possible to replace seal without removing the IP but you just have to be careful.