My brake pedal is a bit low and spongy for my tastes and they dont pump up.

I changed the rear pads and bled the rear lines. The front pads have not even half way worn. All calipers are working , non leaking and rotors are good smooth and thick. Flex brake lines not dried or cracking. Car 10 years old , 75k miles. I'll bleed the fronts to be sure.

I was thinking I need a master cylinder (original).

Could it be the single digit temps lately combined with poor fluid (years of water accumulation as it was a bit brown in the rear)?

Any thoughts fellas?

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Patrick Leber
'84 190E 2.3
'83 Porsche 944 (track car)
'84 Porsche 944 (parts car)
85.5 Porsche 944 (sled)