87 300DT inj pump leaks at del valves

[MBZCOLLECTOR]

I've never seen injection pump leak before at delivery
valves in 40 some years of MB Diesel experience in the USA.
I have the splined socket and and pipe crowfoot and the
gaskets (o-rings).
What else do I have to remove on this 6 cyl model to replace
these o-rings? Intake Manifold?
I read a post somewhere that it could be fuel related.
I have never used any additives in the tank in the 8 yrs
I've owned it. This is a really great driving car so will
fix and keep running as long as possible.
Has anyone else done this job?

[sixto]

You can do it without pulling the manifold (turbo, right?). Release the lines at both ends and the clamps as well so they're more willing to move out of the way.

Check the archives for the torquing procedure. Some manual that's not included in the CD set has a more detailed procedure than 'tightening torque 35Nm.'

You should probably replace the copper washers as well.

Note the orientation of the delivery valve carrier. I'm pretty sure the carrier goes in with the groove down.

Sixto
95 S420
91 300SE
87 300SDL
83 300SD

[psfred]

Fairly common on this engine -- mine were done improperly, with the result that I got the car cheap -- three cylinders weren't firing properly from delivery valve seal leaks.

Definitely replace the seals, they are easily accessable and cheap, and the old ones are likely to leak.

Pull injection lines (and get all new retainer clips, they will break when you try to open them).

Remove locking rings, then unscrew the pressure valve holders. Seal ring is on top, have a care not to drop or lose the spring and vavle insert, as the spring tends to hang in the holder. Replace 0-ring, then re-install the holder.

Tighten to 25 Nm twice without unscrewing, then to 30 Nm. If you don't have a torque wrench, use moderate pull three times with a wait between. If you don't, the seals will leak, and you will have terrible knock and peformance problems from poor fuel delivery.

Use some anti-seize on the screws for the lock rings, the body of the pump is aluminum.

One of mine was so loose I didn't need the wrench to unscrew it.....

Peter

[MBZCOLLECTOR]

Thanks Sixto and Psfred
I have all necessary tools, but never worked on IP before.
Yes it is 6 cyl turbo 197,00 mi, bought it used from Knauz,
at about 140,000. Hasn't been used a lot as the 83 300SD
was my favorite(425,000 now, driveline 'clink').
I only have the 'rubber like' O-rings.
I will get copper seals from dealer and pipe clips.
Thank you very much for your help and concern!

Hope you had a good Father's day
Ken
87 300Dt 197,000
83 300SD 425,000 drive line 'clink' flex plates ok
87 190E 152,000 high NOx Wife's car
68 220D8 200k?+ valve guides shot 15mi to qt oil
63 190Dc 200k?+ no engine problem,except vac pump diaphrams
65 300SEc
92 Cummins/Allison MH 70,000
78 504D Peugeot 70k Can't hold head gaskets
76 504D Peugeot 170k+ nevr had any engine problems
81 5.7D Pontiac 225,000 I replaced IP 3 times, trans shot
83 4.3D Olds 200,000 IP ok, head gasket prob?
"If all engines were Diesel, world history would have been
completely different,IMHO"

[MBZCOLLECTOR]

I replaced all six rubber? orings under the delivery valves
Sunday,June 22,2003. Took about six hours.All springs came up with with the valve bodies. Found the best way to reassemble is to sit spring on top of insert and lower the valve housing carefully down over the spring. Threads won't catch if not seated properly. I did each one individually. Thinking about it later it should be easier to remove all delivery valves from front to back, and install from back to front, carefully not mixing any thing up and covering open delivery valves ports on injection pump. I will post here a list of tools needed to do the job if there is a need.
Hardest part of this job is trying to get the right parts and having to wait almost 3 weeks for the splined socket tool, which was not machined quite right and I had to file off abot .002" off each spline in the socket to get it to fit onto the delivery valve.
Thanks to all here who helped,Ken 87 300DT runs great again