Expansion Tank Hose O-Rings and Flanges

NM8SHUN · 08-20-2023, 06:36 PM

Hello,

New here, and haven't been able to quite find a thread that answers this. I'm hoping for some expert guidance.

I recently replaced the Coolant Expansion Tank. Newbie on the Z4 here, and I didn't watch very closely at the organization of the flanges and O-Rings as I removed the hoses from the old.

Now that I've assembled again, I've got a leak (presumably) where the hoses connect to the top of the tank and radiator.

I think that likely I've messed up the equipment that is on the inside of the hoses inside of the clip. It seems like there should be a hard flange (opening to the two male connections on the tank and radiator), and that there should be an O-ring between the flange and the rest of the hose.

Is this right?

The part I'm talking about is included in the attached photo.

Thanks for your help!

John in VA · 08-20-2023, 09:00 PM

If you car has the M54 engine the Z4 might have components similar to the E46. See:
https://www.e46fanatics.com/threads/...4-s54.1262447/

https://www.ebay.com/sch/i.html?_fro...mw+z4&_sacat=0

You can put the BMW part number into realoem.com & see what other models use the same part.

08-20-2023, 06:36 PM	#1
NM8SHUN Registered 2 Rep 4 Posts Drives: 2003 Z4 3.0i Join Date: Aug 2023 Location: San Antonio, TX iTrader: (0)	Expansion Tank Hose O-Rings and Flanges Hello, New here, and haven't been able to quite find a thread that answers this. I'm hoping for some expert guidance. I recently replaced the Coolant Expansion Tank. Newbie on the Z4 here, and I didn't watch very closely at the organization of the flanges and O-Rings as I removed the hoses from the old. Now that I've assembled again, I've got a leak (presumably) where the hoses connect to the top of the tank and radiator. I think that likely I've messed up the equipment that is on the inside of the hoses inside of the clip. It seems like there should be a hard flange (opening to the two male connections on the tank and radiator), and that there should be an O-ring between the flange and the rest of the hose. Is this right? The part I'm talking about is included in the attached photo. Thanks for your help! Attached Images
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08-20-2023, 09:00 PM	#2
John in VA Colonel 1172 Rep 2,417 Posts Drives: 2015 228i M Sport Join Date: Jul 2007 Location: Leesburg, VA iTrader: (6)	If you car has the M54 engine the Z4 might have components similar to the E46. See: https://www.e46fanatics.com/threads/...4-s54.1262447/ https://www.ebay.com/sch/i.html?_fro...mw+z4&_sacat=0 You can put the BMW part number into realoem.com & see what other models use the same part. __________________ ____________________________________________ 2015 BMW 228i in EstorilBlau II Metallic / Terra Dakota Leather - 6-speed manual, M Sport Package, Cold Weather Package, Lighting Package, Premium Package, Harman Kardon premium sound, Anti-theft alarm system, Blue Metallic Matt Accent Moldings, Aluminum Hexagon Interior Strips, Anthracite Headlining
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