...on the early 996s and 986s are the same part number and all need to be replaced if you still have the original cap.
They tend to lose their pressue-holding capacity and will leak water vapor.
All of them came with xxx.00 caps and Porsche had to modify them 3 more times.
The latest version, as you note, ends in xxx.04 and that version seems to work very well.
Happy Porsche-ing,
Pedro
Pedro Bonilla1998 Boxster 986 - 311,000+ miles:
[www.PedrosGarage.com]
PCA National Club Racing Scrutineer - PCA National HPDE Instructor - PCA Technical Committee (Boxster/Cayman)
Racecar spelled backwards is Racecar
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