I know the pain of the 16v fluid resevoir all to well. It looks full, it seems full, you might even be adding fluid to it, BUT, unless the sucker it to the top and more to spill over into the back compartment, you aint bleeding nuthin' but air baby! My dad and I bled the lines dry trying to bleed the system of air before I got in there with a good light and a magnifying glass and realized the front compartment was full and the secret rear compartment was bone dry. Sneaky Germans! I am sure it serves some other purpose other than confusing DIY guys like us, but, I will not soon forget that mistake and aggrivation of knowing how to bleed brakes and still not getting anywhere. After the rear was full and kept full all four lines bleed in no time easy peasy.
Silly Rabbit.

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Christopher Henkel
1990 190E 2.6 - Arctic white SOLD
1986 190E-16v - Blauswartze
1993 300CE - SOLD
2003 W208 CLK 320 Cabriolet - Magma Red