rschleicher,
Even though this post of your was 2 years old it helped me when I took my Monovalve out yesterday. You are right about previous posts or instructions NOT telling you to replace the coolant cap prior to taking the monovalve out. first time I lost quite q bit of coolant. Second time (today)(dummy here reassembled the monovalve with the coil cover upside down with the slots at the bottom) I had read your post and uncapped the coolant overflow tank, and then recapped it. The loss today was less than half of yesterday's loss.
It pays to read these DIY hints and posts...even if there are some age to them.
Thanks.

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1986 Euro 500SEC "RUF" 9:1CR, "Rose"
1985 Euro 500SEC Cabriolet AMG Widebody
1982 Euro 500SEL "Blue"
2001 Texas Heeler (Aussie/Queensland X) "Sulphie",
2012 Queensland Red Heeler "Squeak"
Best dogs I've ever had.