Injector Pump Lube Oil

IP lubrication is supplied by engine, no lube oil is needed unless the pump is removed.

So the oil port/cap on the pump is for adding oil if and when the pump is removed?

Also, there is no oil visible inside the pump, and that made me wonder.

Plug is to fill a replacement pump.

Small diameter lube oil line goes to pump.

Lambach's post:

Doesn't apply to Randall's car.

There were 3 types of injector pumps for the diesels in those years.

1. M - with pneumatic governor

1. M/RSF and MW - both with a mechanical governor.

The M-injection pump had a separate oil lubrication system that was supposed to be serviced at regular intervals.

The other two drew their oil from the engine block.

One way to tell the difference between the M-type and the other two was that, when you viewed the back of the M-type pump, the bottom of the back of the pump that faced the firewall was round. The sides of the back end of the other two types of pumps were straight and parallel with the corners beveled or rounded off at the bottom.

For the '75 diesels here are the numbers:

For engine numbers 615.912/913/916 the pump was M-type => 240D's up to 1977

For engine number 617.910 it was MW-type => the '75 300D

Your's is probably an M-type. It has it's own oil and uses the same type of oil as your engine (although my mechanic put in synthetic oil when he rebuilt the injector pump).

As you face the injection pump from the driver's side of the car, the you'll see a check plug on the side of the injection pump housing a little less than an inch to the right of the manual delivery pump. Unscrew it and notice what happens when you do. If nothing comes out, the pump's low on oil. Add oil until it comes up to the check bore.

It's not unusual for fuel to end up in the pump. So more typically, instead of nothing coming out, you'll notice a fuel/oil mixture coming out when you unscrew the plug.

There is no drain plug for the pump so I aspirated the oil out of it whenever it came to changing it's oil (If I recall correctly, the recommended way was to back off the bolts on the back plate and let the oil run out. Far too messy and potentially problematical for me).

As far as amount is concerned, I just added oil until it came up to the check bore. It's less than a quart - probably a lot less.

Sorry I can't be more exact but I think you have enough to work with.

Have fun.

r> Also, there is no oil visible inside the pump, and that made me wonder.

There is no way you can actually see the oil by looking "inside the pump". It sits at the bottom of the pump and there is a lot of things between the two of you. Take a thin piece of stiff wire with white insulation and slip it down the oil port and you'll find it down there - if it's there.

Thank you very much--one less thing to worry about.

Now we know why the later IPs are lubed from the engine.

Amen!

One less pain in the butt.

The only nice thing about the M-type that I know of was that the oil in the pump never mixed with the contaminated oil of the engine block. It was "always" clean (relatively speaking). The only contaminate was fresh fuel which, in the case of diesel fuel, is also a lubricant. When you drained the pump, the oil/fuel mixture looked as good as new. It just smelled of diesel fuel.

ron