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2010 e550
All new radiator water pump cooling hoses. First test drive the lower hose came off the water pump because I had the clip off one side. Trailered back home. Reset it and refilled the system.
Seems there isn't a cut a dry bleeding procedure other than run it until operatiing temp and keep it topped up, correct?
Did this again and went to get on the hwy,, did WOT for a few seconds only to get low coolant notice. Pulled over immediately and found the upper hose popped off the radiator this time.
I KNOW it was filled seated and correctly clipped in this time.
What am I missing here?
Ive know wasted $40 of coolant.
Don't think it's hg, no milkshake. Temps stay under 210. No misfire or loss of power, coolant in exhaust etc.
I saw someone mention collapsed motor mounts could let the engine move enough to pull it off. I don't seem to have significant engine movement while parked and throttling it. But it does have 150k miles and idk if they have ever been done.
Last edited by cool breeze; 10-02-2023 at 11:43 PM.
Thanks for the reply. I think those diagram you posted is for the turbocharged w212. Mine is the m273.
The hose that popped off was off of the radiator to thermostat housing on the radiator side.
It was a new radiator and I don't remember taking it off and putting it back on so I think it's oriented correctly.
The post you linked I read and will go over again to make sure it's correctly oriented but I don't think that is the issue. What else could it be if that's not it and is there proper way to bleed these?
Your M273 hose design uses the same quick clip U shaped one like mine, so the caution applies the same, be it at water pump or radiator side. It is the same mechanism. https://www.ecstuning.com/b-genuine-...se/1645010682/
The other possible weak link with this U shaped quick clip is ....also the plastic fittings where the hose is inserted into.
If the plastic fitting for this U shaped quick clip has worn out at the locking section , the hose can pop out.
See image below and use ur own imagination on possible failure :
Imagine a hose ( male ) with steel hose end, is being inserted into a female PLASTIC hose fitting.
Go and inspect your hose again, make sure the U quick clip L bent edge face the correct orientation and the plastic female fitting is in good condition at the
locking section.
To make sure you inspect correctly, you may need a mirror too.
Here is a good video explaining how the L shape edge of the U clip will lock itself to the plastic body of the female fitting, with the provided "parking space"
Do take note, some of the U clip has both L edge facing one direction, like below and mine is like this too :
Some will have the L edges facing different, like below and the utube I linked. Older MB model compared to W212 M276 era.
So maybe M273 may use this kind of opposite facing L edges U clip.
I forgot to tell you the correct way to install a hose using this kind of locking U clip, just in case the link to my old post was not clear enough.
01. To remove a hose of this kind, DO NOT remove the clip all the way , you only need to raise this U clip 1.5cm or 0.5 inch,
so that the locking part of the U clip is no more going to lock with the hose end locking channel, that raised/bulged shape locking channel.
Lifting up a tiny bit of the U clip, it will cause U clip to actually open up, like expanding side way.
I hope you understand my English ...
If you remove the clip all the way ( I did ), there is a chance that it may get its shape distorted ( I did ).
So I bought new ones, because the old one I ruined , one of them...
When observed properly, it is no more shaped properly like a new one and that will make its locking performance poor.
.
02. To INSTALL the hose end ......... the U clip is to be in a LOCKED or maximum inserted position. U clip will automatically expand when the hose end is inserted,
because the hose end design is as such it has a soft slope when being inserted, but will not allow hose end to come loose when the U clip already
got locked properly into the hose end locking channel. You can hear and feel the positive CLICK sound when the hose end got the U clip into the locking channel, do a pull test too after that.
Good luck
EDIT / ADD :
I think I have to correct the information, just in case your U clip design is the old one with near equal width at at its L edge.
See the green region. If yours is like the one on the right side image, that design of U clip will expand its shape when U clip get lifted up a bit.
The left side image, that older U clip design probably will not expand its shape when being lifted up a bit....this oldie design may need the U clip
to be totally removed when removing the hose end.
Take a look at your hose end, does it have a soft slope for its locking channel ?
If it doesn't, you probably can not use the hose end insertion method I described in number 2.
Good thing I am helping you here, now I am able to see design changes on the U clip over the years and I need to be careful when dealing with older MB using that kind of U clip.
Last edited by S-Prihadi; 10-04-2023 at 03:36 AM.
Reason: add info
@S-Prihadi thank you for the excellent info!
I did not have the clips fully seated on another hose so that probably was the initial prblem. Also a friend recommended using some lube on the hose when inserting. That finally let the new hose click and fully seat into the rad. Been driving around with water to test it and everything seems to be holding nicely.
Next up is to drain and refill with coolant.
The new Nissens rad i got doesnt have a drain, but it has the valve. So not sure if i can drain from there.
I cant see any block drains on here or they are too far out of the way.
If i drop the hose off the water pump, i think that should get most of the water out.
10-02-2023, 11:33 PM
