560 SEL brake problem

Hello,
I'm new to this group... and to newsgroups altogether !
I am noticing 'sponginess' when applying the break pedal on my 1989 560SEL. I don't think it is due to air in the brake line. There is no noticable
leaks that I can see. Can anyone tell me the correct procedure, or what clues to look for, in order for me to cancell out a 'master cylinder' problem?
Thanks in Advance TD
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Tibor D wrote:

How long since you changed the brake fluid? It should be every two years for optimum performance on the older cars.
JJ
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Yep, you need to change your brake fluid.
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OK, I'll bite! What happens to brake fluid that necessitates (is that a word?) it be changed???
John

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Brake fluid by nature is hygroscopic... they love to absorb water... when they do absorb water, they lower the boiling point of the brake fluid... Once that happened and fully saturated, the brake fluid will boil under high stress and create steam... which is what causes sponginess.
Air is compressible, liquid is not compressible... there is no buts... no but whatsoever... breast implants is not in a rigid casng... LOL...
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Excellent explanation Tiger! Except for the breast implants part, that just was a distraction...
LOL, Marty
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LOL... my mind wanders... my mind wanders... LOL
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Thank you for the explanation. My mechanic tells me that the fluid is getting dark and needs to be changed. I just put it on my list of 1000-ways-to-deplete-my-checking-account.
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