E38 coolant leak

Coolant level was down on our 2000 740iL. I noticed some coolant crust on the upper radiator hose 'elbow' connector that I'm pointing to in pic. I decided to keep an eye on it and filled (possibly overfilled) the system. A couple of days later the hose blew off the T-connector (also in pic). Is the apparent seamless clamp reusable or do I just replace it with a standard hose clamp? Also, to address the leak, how does the connector remove from the aluminum neck? I removed the electrical connector type retainer wire. The connector wiggles but seems to be retained by a plastic stem similar to a rivet. Is replacing this leaking 'elbow' connector my only option? Thanks in advance!

Best to just replace the entire hose.

Once you remove the clamp wire, the hose slides off. Try not to wiggle it too hard, you don't want to strain the radiator neck.

Thanks much for this and the tip for bleeding procedure

Originally Posted by M.Wong

Best to just replace the entire hose.

Once you remove the clamp wire, the hose slides off. Try not to wiggle it too hard, you don't want to strain the radiator neck.

Yes, be very careful about the radiator neck, especially when retightening that clamp! I tightened mine a bit too much when I replaced the hose and cracked the neck. I needed to buy a new radiator.

This applies to all BMW's
Over heating and coolant and expasion tanks blowing out are caused by viscause fan couplings failing and head gasket failure. In my forty years of working on BMW's I find CONSTANTLY that the cylinder head stretch bolts loosen off which causes the head gasket s to fail. I have seen this on cars less than two years old with around 15'000 miles.
Some six cylinder engines 1992 till 1996 ish had plastic water pump impellers which failed which also causes over heating problems but a skilled BMW technician will spot this by an erratic temp gauge.

i had almost the same thing happen around the same time of year too. i replaced both upper and lower hoses along with the temperature sensor that is located in the lower hose. was about $90 for parts.

Could someone post the proper bleed procedure if available? I'm new to my 2001 740iL and the first thing I replaced were the two hoses and thermostat - the expansion tank was leaky and cracked and had a broken bobber inside. But now I see the coolant level go down in about 7-10 days and starting to wonder? Anyway knowing the proper way to bleed the air would be helpful - thanks.

Hi there, You will see a bleed screw facing upwards in the radiator area, It is best to do this with a cold engine, Undo the screw and top up the header tank until coolant air bubbles stop coming out of the bleed screw hole, refit the screw and top up the header tank until the bobble is level with the top of the header tank screw thread. Run the engine until hot and then let it cool right down and re check the level wich should be as before. Again I will say that over heating and coolant loss, Fractured header tanks and blown out radiators is due to fan coupling failure and loose cylinder head boltsleading to gasket failure.