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Old 08-03-2013, 05:51 PM
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bluebee bluebee is offline
Seek to understand,^Value
Location: San Jose, California
Join Date: Mar 2008
Posts: 25,236
Mein Auto: 02 BMW 525i M54 auto 130K
I was doing some research for someone needing a coolant bleeding DIY, when I ran into this cryptic sentence:
Originally Posted by Aussie528iT View Post
The expansion tank does not have an overflow tube. Coolant is vented through the cap (cap is hollow inside) and any over flowing coolant will leave white stains around the top of the expansion tank. This is normal but leads some people to think their expansion tank is faulty and leaking
So, if the expansion cap is the one-way coolant overflow valve (with a two-way air check valve built in), then what is the purpose of the so-called expansion tank overflow tube that goes from the expansion tank neck to the top of the radiator?
Please read the suggested threads and add value, either by pictures or by descriptions, so the next person stands on your shoulders.
See also: E39 Bestlinks & How to easily find what you need

Last edited by bluebee; 08-04-2013 at 04:00 PM.
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