Fuel Injection Pump Oil

[Jordan]

Well, finally got around to changing the oil in the fuel injection pump.  Obviously, as you will read, it should have been higher on my to do list.  I finally found the dip stick, which is unscrewed using a flat head screw driver or a 14mm wrench.  Does not have the T cap I have seen on other pictures which is why I missed it.  Instead of removing the oil from the dip stick I went in through the breather cap on the top of the pump (see picture).  I used a syringe with a flexible tube to extract the oil, very black and thick.  I could get the flexible tube down about 200mm (8in) into the pump.  It just kept on coming until I extracted about 700ml of oil.  If the capacity is around 250-280ml as I have read on other threads, mine was way over capacity.  There is no fuel smell.  I suspect the PO didn't know there was a dip stick and just filled it up.  Would this have caused any long term damage?  I keep shaking my head just thinking about it.   

Since the oil supply in a 230SL FIP is contained, has anyone used synthetic oil in their pump?  I do not use synthetic in the engine, but wondered if it was worthwhile in the pump itself.  Or do I end up with the same problems, leaks where there previously weren't any.  I have the standard 120R11 pump.
Thanks again for all your assistance.
Marcus 

[badali]

I just used the same oil that I put in the engine.  I changed it a few times since I don't think it was done much before.  It is so clean now I can not see it well on the dip stick...

[twistedtree]

For what it's worth, my R11 pump only too 150ml - at least as best I could tell.  With clean oil it is quite difficult to see it on the dip stick.  The 250SL uses an R18 pump which still have the separate oil reservoir.  Perhaps that pump has a larger capacity?  I'd be interested to hear how much yours takes.

[Jordan]

Just thought I would follow up, my pump only took 150ml to get to the full mark, similar to twisted tree.  I note others have put 250 to 280ml in their pumps.  Do the different pumps take different amounts of oil or could it be I still had some left in my pump?  Just want to clear up the discrepancy.
Thanks
Marcus

[twistedtree]

I screwed the dipstick all the way back in each time I took readings.  I take it you did the same?  Maybe others didn't?

[Jordan]

Yes, I screwed the dip stick all the way in each time I took my reading as I had read that on another thread.

[Benz Dr.]

Very likely you still had some oil in the pump. The main thing is to have it at the full mark when you get done.

  My 250 doesn't have a dip stick on the back and is more like a 280SL pump so not all of them are alike.

[twistedtree]

Dan, do you know which pump you have in your 250?  That's interesting if it doesn't have an isolated reservoir.  I've seen two other 250 both of which do.