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?