Dear friends:

Please take a look at the attached image first.

I tried to flush and change the brake fluid on my 1984 300SD using Power Bleeder, which is designed to apply pressure on the fluid in the brake reservoir. However, the brake fluid kept leaking excessively through the 2 black rubber caps as shown in the image.

My questions are:

1) What are the proper name and part number for those 2 black rubber caps?

2) Before flushing, I sucked out the old black brake fluid from the brake reservoir. However it seems that my brake reservoir has 2 different "chambers", and I could only suck out the old brake fluid from the outer "chamber" because there's no hole through which I could suck out the fluid from in the inner "chamber". I saw a little plastic plug on the right side of the reservoir (in the image) and wondered whether this plug is used to drain the old fluid from the inner "chamber"?

I had changed brake fluid on a 1981 240D and did not encounter
a similar problem. Is there any big difference between 300SD and 240D brake reservoirs?

3) Have anyone tried to flush brake fluid using Power Bleeder on a 300SD? I'm still wondering whether 2 new rubber caps can keep the brake fluid from leaking under pressure from the Power Bleeder, because it looks like these 2 caps are only loosely attached to the brake reservoir.

Thank you very much for all your information!

Best regards,
Eric

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