I have a fuel leak on my 1983 300D at the injection pump. It looks like the leak is below where the "spider" metal fuel lines connect to the pump, so I have to take off the two nuts on the pump.

I believe someone here indicated that I need to replace the o ring and either a spacer or washer that is under the plate.

Does anyone have a source for these parts? I've checked fastlane and couldn't find them.

Are there any special precautions I should be aware of when replacing them, other than being real clean?

Thanks
Joe

Are you sure the leak is BELOW the plate with the two nuts. You REALLY don't want to remove those two nuts. If you move the plate under the two nuts, you are changing a critical adjustment.

Have you pulled the piece under the line, the spring, the valve, the sleeve and the copper washer? If you have not, maybe replacing the copper washer, or tightening the long fitting under the line will cure your leak.

I had a leak at this area which tightening the fitting corrected.

Good luck,

Larry

No, I am not sure it is below the plate. I assumed, probably incorrectly, that was the only place left to leak given that the top nut is tight.

I haven't loosened the 2 nuts holding the plate on yet. I suppose I will try to tigthen the nut below the nut that attaches the spider lines. Maybe that is where the leak is?

Any idea how tight they should be?

Thanks
Joe

Joe,

I don't know in foot pounds. I took mine apart because it was not hitting on number one. I took everything in there apart and cleaned it as thoroughly as I could because that cylinder wasn't firing.

I put it back together and got the cylinder firing, just lucky.

I drove it some and saw a leak there. I loosened the line and cinched down the fitting pretty good. Then tightened the line firmly.

Unless it's a cylinder head, rod nuts, main bolts, or other critical parts, I don't use a torque wrench. Just tighten things by what my years of tightening things tells my hands to do.

Sorry I can't give you more information.

Good luck,

The copper washer (seal) seals the pressure in the injection line. The o-ring at the base of the pressure valve holder (what you unscrew) seals the pump element from the outside -- this is what is leaking.

I got new seals from my indy mechanic -- FastLane has them, too -- look for pressure valve holder seals under injection pump.

The second "nut" is actually the pressure valve holder -- it is all one piece. Don't move the two nuts and hold-down plate -- on your pump it is the pump sleeve calibration (it is set to deliver the correct amount of fuel at the correct time) -- if you move it, fuel deliver timing and volume may be wrong for that cylinder.

If I remember correctly, you can still unscrew the pressure valve holder without loosening the two nuts -- they are 13 mm. If you have a simple plate with serrations that fits over the pressure valve holder, it is just to keep it from unscrewing, and you will have to take it off. It will be held on by a pair of screws, not nuts.

Torque is 30 ft/lbs for the 603, that should be sufficient for the 617, too. Probably best to get new seals and new o-rings -- the seals may or may not work after being used.

Peter

__________________
1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!

Peter,

Thanks, I did not remember the o-ring at the bottom of the fitting. I was leaky in tightening mine and getting it to stop leaking. I retightened the line at the same time, so MY leak may have been the line.

You learn something new hear every day, and that's a fact.

Have a great day,

Larry:

For being such a simple concept, diesel engines are a little complicated!

The locking rings on my 300DT have been moved, so either someone fixed a leaking o-ring and screwed up the seals, or has tried new seals to fix the rough idle and knock. I'm hoping that it is the former rather than the latter -- else I'm in for major engine work, probably a bent rod on #4, along with leaking head gasket, etc.

I'd guess you didn't get the pressure valve holder sealed on your 300 when you set the injection timing -- nice that it got fixed so easily!

Peter

__________________
1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!

Peter/Larry

Thanks for the help. It indeed is leaking from where the element screws into the injection pump.

The spider lines are connected with a 17MM, and I had no trouble removing it. I then tried to remove the element but couldn't get it off. It looks like 15 mm or 16MM, which unfortunately I don't have a wrench or deep well socket for.

It seems very tight, maybe because a previous owner trying to stop the leak, I don't know.

Is it right hand thread, ie, I loosen it counterclockwise.
I couldn't find the copper seal or the o ring on FASTLANE, but with give them a call tomorrow.

Do you think I should change all of the seals at once, or just do the one?

I'm half way through adjusting the valves, and the turbo air tube had a duct tape repair that I am fixing correctly.

thanks Joe

Joe:

My unwritten rule on IPs is that if they aren't broken, I don't fix them. Just replace the one o-ring that is leaking and leave well enough alone. If the others leak later, you can fix them then. My 220D isn't leaking at all, and is 30 years old this month!

The pressure valve holder is, I think, a normal right-hand thread. Shouldn't be all that tight. Again, check the "ears" -- if they have a nut on each end, leave them alone. If they have a screw, and have splines that fit over the holder, you have to take them off, they are locks to keep the holder from unscrewing. If you still can't get it out, call a diesel injection service place (you can find one in the phone book) and ask! Much better to appear ignorant than break something. You may very well find a place to do the seal replacement for you at small expense!

Peter

__________________
1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!

Thanks again.

I am afraid of breaking something. There are nuts, not screws on the plate so I know to leave that alone.

I'm a bit afraid that that previous owner cranked it down in an attempt to get it to stop leaking.

The Hanes manual also tells you to remove the element to connect the drip tube up for injection timing check. They don't say the threads are left handed, so I would have to assume it is right handed.

Thanks

Joe:

Unfortunately, you are probably correct -- and you could tighten that holder with a 10 ft cheater bar and never stop the leak, since that seal isn't the one leaking! The holder probably hasn't been unscrewed since the pump was made, too -- probably stuck.

If it makes you nervous, talk to a diesel injection shop. Some will do the seal repair in the vehicle, if you beg some -- you don't want to take the pump out just to change a seal!

Peter

__________________
1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!

I just went through this last week – replaced all of the brass O-rings under the delivery valves in the IP. I was trying to eliminate the loss of fuel (bleed down) in the injector lines while the engine was off. (It ends up that two of my ‘new’ Bosch rebuilt injectors are the culprit on that issue.)

The seals are under the delivery valve holders, which are in turn under the injection line fitting on top of the pump. The need for cleanliness _cannot_ be overstated when opening up the pump.

Unscrew the injection line fitting(s) (“pipe connections” in MBZ parlance) on top of the IP in the normal counter clockwise rotation – they are NOT reverse threaded. They may be pretty tight – don’t worry about excessive force (within reason) when unscrewing them – they’ve been in there for a long time. Some penetrating oil may help. Once you pull off the fitting, use a small magnet to fish out the delivery valve & holder. This is a good time to clean the delivery valves with some carb cleaner while you have them out. Pull out the old brass o-ring seals, put in the new ones – pretty straightforward. Before putting the delivery valves back in, use the primer pump to flush out any debris or crud that is left in the pump chambers. When you reinsert the fuel line fittings, it is important to oil the threads to get the proper torque value on them - on the 617 engines, they should be torqued to 40-50Nm. NOTE: When you torque them down (after they are finger tight), do it in ONE sweeping rotational motion – don’t intermittently ‘sneak up’ on the torque setting.

RTH