We've been slowly returning (read: replace everything that's worn and never been touched :) a '90 GL to the road and started to replace the coolant tank this weekend. Would have it finished if the right part was given to me...

Anyway -- the PO had complained that nobody could ever get the cooling system correct, and he'd start to see that cheery blinking light before getting towed home. So here's the question: when I removed the coolant tank there was the crack I expected at the seam, but also it was cracked on top near the cap. The crack at the seam is new (or wasn't seeping before) -- I'm curious if the other crack could have been there for awhile... thoughts?

Oh, here's another question: the tank I removed is part# 025 121 407A while the replacement tank a friend delivered from his shop is 100 121 035. It's obviously not the right part (top hose nipple is way too large), but I'm curious what it's really for. Any ideas?

john