My son said the 1985 300D was leaking brown liquid, but not quite oil. I found the lift pump outlet fitting loose, dribbling fuel when I got it home. When I removed the pump to replace the gasket, I found the top ear of the pump (cast-steel?) snapped off (photo 1). That let it leak oil as well, so the drips were a combination of diesel and oil. The resulting shaking may have loosened the fuel fitting, or perhaps I never tightened it.

I rebuilt the pump when he was home at Thanksgiving, in hopes of fixing a rough idle. I didn't have the proper gasket and no time to wait, so used a simple washer one from another engine kit (black). It was only slightly thicker, but by leaving the ear overhung, it might have stressed it to crack. Since then, I bought the correct gasket (top, photo 1).

The last photo is the lift pump disassembled from the Nov rebuild. I bought the plastic check valves & springs on ebay ($15 for both). The originals didn't look degraded and the rebuild didn't help, so I just made problems for myself, but occasionally poking at these old cars gives results. One P-P posts says a lift pump rebuild helped greatly. I took the roller apart, thinking there might be bearings to replace, but it is just a shaft & disk so if it feels tight it is fine. I replaced the shaft O-ring w/ a Viton one. You must pick it out of its groove in the bore.

Fortunately, I had a spare lift pump from my failed engine. Otherwise, P-P sells new ones for $459 (Bosch) or $570 (genuine M-B), and there is always the junkyard.

Finally, in case it helps somebody, some notes I took:

Bosch Lift Pump in 300D OM617 turbo engine.
FP/K22MW22
Casting Numbers:
"02720" on side
triangular base: "2" one side, "2445703010"

Attached Thumbnails

   

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1984 & 1985 CA 300D's
1964 & 65 Mopar's - Valiant, Dart, Newport
1996 & 2002 Chrysler minivans

If by chance the lift pump kits become no longer available there will be a lot of howling. The 10.00 master cylinder kits I used on good clean bores seem to have almost disappeared.


Perhaps for those that expect to keep their 123s very long term. Or passing them down in their family. Building up a supply of the common failing parts from a wreck and other sources might be considered. Locally they are now becoming quite scarce.

Mercedes sells the Valve Kit you describe that has enough to change the Valves but unfotunately lacks the little O-ring.

There is several sources for the generic kits that have all of the gaskets and Oi-rings for the Fuel Supply/Lift Pump. With the shipping they were around $17 or sometimes less. Generic Lift Pump Kit as on eBay. Complete kit.Gasket kit to fit Bosch* Supply Pumps ADS-DGK-301

Lift Pump Kit Hunter 617.951-952
OM617.951 and .952 Lift pump Repair kit W126.120 300SD W123.133 300D - PeachParts Mercedes ShopForum
Lift Pump kit post #48
fuel pressure - Page 3 - PeachParts Mercedes ShopForum

More Fuel Supply Lift Pump rebuild kit stuff
Refreshing the fuel pump on an OM617 (European spec – non turbo)

0000900210 Fuel Supply/Lift Pump kit for mine Bosch kit# DGK301 ($14.60 CDN).
2910-01-255-1278 DGK301

There is also a kit for the 240Ds with M-type Fuel Injection Pumps.

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84 300D, 82 Volvo 244Gl Diesel

When I bought my lift pump rebuild kit, the Bosch fuel injection shop told me that these same lift pumps are used on a huge variety of equipment and engines, just about anything that uses a Bosch inline IP.

I just don't see the odds of this kit going NLA any time soon being high.

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617 swapped Toyota Pickup, 22-24 MPG, 50k miles on swap

That looks like the lift pump that came on the SuperPump, "M" based as y'all may recall. So far so good. Mine has no primer pump and I understand that they came with and without at different times. Once I got my first startup all has been groovy. My guess is that if you can't find the lift pump parts here you can contact Goran and he'll be able to fix you up.

Dan

That is true to a certain point. The Fuel Supply/Lift Pumps on the 240Ds on the M type Fuel Injection Pumps has a different type of valves in it (disc valves).

The Fuel Supply/Lift Pumps on them also only have 2 holes in the pump flange.


Also the Hand Primer threaded area can be different in diameter so not all hand primers are going to fit.

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84 300D, 82 Volvo 244Gl Diesel

@Diesel911

Yup not exact, but enough close enough pumps to be made to work. Also on our engines it's easy enough to swap in an inline electric fuel pump. Would require building a blockoff plate for the factory lift pump, but wouldn't be too difficult.

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617 swapped Toyota Pickup, 22-24 MPG, 50k miles on swap

On the 617.952s and W123s people seem to want to electrify stuff that held up for 30+ years.

If you rebuild you fuel supply/lift pump it should out last the Car. And, it is a cheap fix.

It is the Fuel Pressure Relief/Over Flow Valve that is the weak link if not replaced.

We are unfortunate in getting these vehicles far after their prime and after neglect or even abuse by prior owners.

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84 300D, 82 Volvo 244Gl Diesel

An electric pump is always a backup plan. But I'll probably grab another lift pump for backup on my next junkyard trip. I was encouraged to find both lift pumps looked pristine inside. My next plan is to add a fuel pressure gage at the IP inlet. Others have done so by tapping the banjo bolt at the IP, which acceses it after its spring inlet regulator, and what the IP cares about (should be ~10 psig).

One advantage of diesel is that once running, you are immune to total electrical failure. An electric pump would void that. But, I am prepping to go electric on the vacuum pump since those can destroy the engine and I had one come close already - roller bearings failed, arm dragged and wore half thru in 100 miles.

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1984 & 1985 CA 300D's
1964 & 65 Mopar's - Valiant, Dart, Newport
1996 & 2002 Chrysler minivans