Coolant Leak

Hello All,
First let me inform everyone that I did research old threads first. : ) Anyway my coolant level low indicator has been coming on for a month. well actually in came on about a month ago and I checked expansion tank and it was alittle low. I purchased BMW coolant and topped it off.
Well it came on again today and let the car cool and I inspected the hoses where I discovered a mini crack on the upper expansion tank hose ( water vent hose ). It was actually on the plastic part of the hose. I checked online for the part and found it to be around 35.00.
To install this part myself, i must drain coolant from the bottom and release the bleed screw for a good flow. The part # 17127519247. I noticed that the plastic tubing doesn't sell separately. Is it a certain procedure to install this hose. I do not want to take to dealer to do this and is this a normal or usual wear part where leaks occur?
Thank you ,
Blake
My 2005 645ci has 66,000 miles.

If you are talking about the plastic pipe & hose that run across the top of the radiator, it must be replaced as one piece. This is a very simple install. The connection on the drivers side can be replaced with a simple hose clamp. The radiator will self bleed on the 6 series by itself. There is a very good chance that your expansion pipe will fail shortly. It might be something that you want to change while you have the cooling system open. I would also suggest that you only use BMW coolant, to prevent further problems with the cooling system.

To remove the hose from the expansion tanks, slide locking clip out, then wiggle the hose loose. The clamp on the drivers side will need to be expanded, then replaced with a new hose clamp. You do not need to drain the cooling system to replace this hose. Make sure to bleed the pressure off the expansion tank 1st.

Good Luck!

Thank you Herb! Is there a bleed screw near the expansion tank.

Just loosen the cap on the expansion tanks slowly before to bleed off pressure in the cooling system. After that, remove the hose. The line that you are replacing, is the bleed line. You can watch the air disappear as it returns back to the expansion tank. The drain screw is at the bottom of the radiator, on the passenger side.

Herb ,
The part came in and the install was easy like you said. Thank you for your help .