Can't get oil extractor to extract
 

I bought an Astro oil extractor and can't get it to suck out the oil. I called their cutomer support and was told that I'm not getting the extractor tub all the way to the bottom of the oil pan. Well, I've pushed until it hits metal. And the best I can suck out is about one quart. The support person said he never advises nor uses the extractor for engine oil because it is difficult to get the extractor tub to the bottom of the pan. I've read of others on this form using oil extractors successfully.
I have a 1988, 420 SEL. Does anybody know whether there is a way to get the extractor tub to the bottom of the oil pan on my model Mercedes, or any other advise on getting this extractor to work?

Hi Lakelover:

Try to extract the engine oil while it's still really HOT HOT HOT!
Hot oil flows much more easily.

That's the key.

Regards,

Eric

Make sure your extractor isn't leaking. If air's getting in, you won't have a vaccum long enough to suck oil.

Sixto
91 300SE
87 300SDL
83 300SD

Eric,
Well the engine was up to temperature when I tried extracting the oil but perhaps not really hot, hot, hot. Does the dip stick reach the true bottom of the oil pan? I'm thinking not but rather that it reaches a point that can measure the low point on the dip stick. The extractor tub will go about 2" further in than the dip stick before it "thumps" on the bottom or something. So, am I at the true bottom of the pan or is there an obstacle such as the oil pump or other object directly below the dip stick tub that I might be hitting? If so is there any way of getting past such an object?
Jerry

Try sealing your extractor's tube at the dipstick tube instead.
The dipstick tube itself is actually designed to be used for suction extraction, and seems to work better.

1) Put your device's extractor tube in, but just slightly (1/4 inch) off the bottom of the pan.
2) Make an air seal around your extractor tube at the dipstick tube using duct tape or similar.
3) Suck away- Bet it will work...

Best of luck.

Not being familiar with the Astro extractor, what is the extraction tube made out of? If it is plastic, do NOT try to suck HOT oil...it will just collapse on itself and you won't get much oil. Let the engine cool down a bit and try to suck warm oil, not hot.

I think that you are at the bottom of the pan. If you weren't all the way down, you would hear the tube sucking air.

I think your oil is just too hot.

You might try an angle cut at the end of the tube so the end doesn't seal itself agains the bottom of the pan.

Might there be a layer of sludge at the bottom of the pan?

Sixto
91 300SE
87 300SDL
83 300SD

dont your oilpans in USA have a tapping plug?

here in Sweden it has.... :D

Niklas - unfortunately, it is probably slowly becoming an option;).

POOR BASTARDS :cool:

Dakota,
The extractor tub is made of a fairly hard, transulcent plastic. I don't think it would colapse unless it got very hot. I would say the oil temperature was warm but not hot, hot.
Sixto,
I didn't see any sign of sludge on the tip of the tub when I pulled it out. Cutting an angle at the end of the tub sounds like a good idea. I might try that.
Csnow,
Sealing the dip stick tub also sounds like a good idea. Actually, I tried that with a rag. Duck tape will work a lot better. I'm not sure but I think I could hear air being sucked in by the extractor as though the pan was dry leading me to think the extractor tub was not into the oil. After failing to get oil out with extractor I reverted to the old fashion way of draining the oil. . . through the drain plug. It's a nuisance but I may have to continue doing that way. Also, I had removed the oil filter when I started using the evacuator. Do you suppose I should have left the oil filter in place before sucking out the oil?
Thanks all for your advice. Any more ideas are welcomed.
Jerry

I don't agree with sealing the suction hose in the dipstick tube. You're not trying to create a vacuum in the crank case. I remove the oil filler cap to ensure that vacuum isn't created in the crank case as that would only make it more difficult to extract oil.

Counterpoints?

When I got my Topsider, the nipple that the suction hose connected to was loose allowing air to leak into the chamber. The Topsider people sent me a new fitting and it's been fine since.

See if it'll hold pressure. Not as telling as submerging it but a whole easier.

Sixto
91 300SE
87 300SDL
83 300SD

Oil filter should not make any difference. It sounds to me like the end of the hose is not in the deepest part of the pan. Sounds like it is working ok seeing as how you are getting some out.

I tend to believe the the problem is that I cannot get the extractor tube in the deepest part of the oil resevoir. So, the question is: how do I get it deeper. Is my particular model (88' 420SEL) of mercedes the problem? If I had a cross section of the oil pan and the dip stick tube I could see what the restriction is. Is there such a cross section view available? Or does anybody have such a view who can explain what may be obstructing the entry of the extractor tube? Apparantly nobody else has had this problem.
Sixto, why didn't I think of checking the extractor pressure holding. Guess I'll use it on a bucket of water and see how it works.
Jerry

Jerry,

Be sure to also compare the length of suction tubing to the dipstick length. This will quickly tell if you are reaching the bottom of the oil pan.

My experience is the oil extraction works best with warm but not hot oil. Too hot allows the plastic line to collapse on itself. I am looking for a metal pipe to replace the plastic line that goes into the dipstick tube.

Keep us posted,

Haasman

Oil Extractor
 

"Lakelover" : If you check the Maintenance Manual and refer to the section on oil changes, there is a drawing of the special adaptor used by MB to suck the oil from the engine via the dipstick tube. That drawing shows that the adaptor and suction tube are only inserted into the top flare of the dipstick tube, about two inches. The dipstick tube evidently goes right to the bottom of the oil pan, or close enough, so suction applied at the top of the dipstick tube is enough to draw out all the hot, hot oil.

Rather than try to purchase the elegant adaptor used by MB, I purchased a length of 3/8 inch I.D. transparent, braided, PVC tube from Home Depot. The O.D. is about 1/2 inch and fits easily but snugly into the flared portion of the dipstick tube. I connected that back to the container for collecting the hot, hot oil and that container in turn is connected to a vacuum source. The oil filter cover is first removed, then the vacuum is applied. Yesterday was my fourth experience using this method and the measured volume of the oil removed was 7+ liters....I am satisfied that I removed all that was in there and it took about 15 minutes, with no mess.

DHA

Does this tubing you got from Home Depot simply jam into the dipstick tube or does it go all the way down into the bottom?

Haasman

No need to get the extractor tube to the bottom of the pan. Save yourself the trouble, and seal to the dipstick tube instead.
It was designed for this.
DHA's method is right on track.

Haasman: I confirm what csnow has already noted. The 1/2 inch OD, transparent, braided PVC tubing is inserted into the top flare of the dipstick tube. That O.D. will not allow the tube to enter beyond the flare and makes a tight seal. The transparent tube is apparently heat resistant enough and the internal braiding makes it strong enough to withstand temperature and vacuum. Its neat to watch the last few bubbles of oil pass along the tubing, signaling that the sump is dry.

DHA

DHA, Thanks for the tip. I'm going to try it. From your description it sounds as though you use a motorized vacuum source. I'm wonding if it'll work with a hand pump (Astro). Guess I'll find out.
Jerry

Lakelover:

Not to beat this thread to death, but the powered vacuum source is an old 1 HP ShopVac. The ShopVac pipe fits nicely to the pouring spout of an old 2.5 gal plastic gas can (holds 10 Liters). I drilled and enlarged the air vent on the gas can to accept a 2 inch long 1/4 inch brass nipple (Home Depot). The O.D. of that 1/4 inch brass nipple is 3/8 inch. That in turn fits the 3/8 inch ID, transparent, braided, PVC tubing. I used about 4-5 feet of that tubing and, as stated in my earlier reply, the tubing snugly fits into the top of the dipstick tube of my car. Its not Rube Goldberg...its more like Swis Family Robinson. The oil never reaches the ShopVac.

DHA, you're very resourceful. Too bad I don't have a shopvac. I picked up a 1/2" OD, PVC, this morning and found it a bit small for the flang on my dip-stick tub. Looks like I need a 5/8 or 11/16 for a snug fit. It'll be tomorrow before I can see what larger size is available. Anyway, the point is that one-size doesn't fit all models. Jerry.