[greg2006325i]

Upper radiator hose broke while driving yesterday. Ordered new parts.
Having quite a time getting the hose removed from the engine and radiator..
I am using as much force as I can muster pulling straight out Very afraid of pulling
or wiggling too hard and damaging the connector to the radiator and having to
replace it also. Any tips for getting it out?....I have completely removed the locking
pins on both ends. Thanks Greg

[whyzee125]

Spray a toot of penetrating oil in it or use a mini crowbar to apply a tiny bit of outward force while wiggling it side to side. I've never damaged a radiator while doing this though obviously there are no guarantees. These cars are at the age where likely more than half of them are not on their original rad so unfortunately it could be collateral damage. I think you'll be okay though.

[greg2006325i]

Originally Posted by whyzee125

Spray a toot of penetrating oil in it or use a mini crowbar to apply a tiny bit of outward force while wiggling it side to side. I've never damaged a radiator while doing this though obviously there are no guarantees. These cars are at the age where likely more than half of them are not on their original rad so unfortunately it could be collateral damage. I think you'll be okay though.

thanks for the reply....pulled extremely hard and it popped off....antifreeze leaked all over the belt when it broke...not sure if I should get a new belt or try and clean the belt and pulleys with simple green. etc...

[lowrydr310]

Glad you got it off. I'm the future, another trick that works is heat. I used my wife's hair dryer last time, but have since ordered a real heat gun. Get the connector nice and hot, and that helps them come off much easier.

Antifreeze on the belt is fine, just rinse it off with water before starting. Even if a little is on the belt with the engine running it should be fine as long as your tensioner isn't shot and the pulleyn isn't out of alignment.

[mainbearing]

This is a very common failure. You should also check the "Mickey Mouse" flange below the oil filter housing if that has not already been replaced by a metal Mickey.

Heat gun, silicone spray or penetrating oil, or in my case Dremel carefully cut and then pry open the upper hose connector.

The upper radiator hose bibb is known to break off when people tried to remove the connector. That area of the radiator is also a known failure spot, such as the picture in this thread:
https://www.e90post.com/forums/showthread.php?t=2222208

Or once the cooling system cooled down to luke warm and there is no pressure in the system, try working the hose connector loose at that time. This is an alternate heat method that I used.

https://www.e90post.com/forums/showthread.php?t=2010192

[Cloverdale]

Originally Posted by lowrydr310

Glad you got it off. I'm the future, another trick that works is heat. I used my wife's hair dryer last time, but have since ordered a real heat gun. Get the connector nice and hot, and that helps them come off much easier.

Antifreeze on the belt is fine, just rinse it off with water before starting. Even if a little is on the belt with the engine running it should be fine as long as your tensioner isn't shot and the pulleyn isn't out of alignment.

The heat gun makes the impossible (that lower rad hose on the passenger side), easy peasy!

[krhodes1]

Heat is your friend here. And I used a dilute dish soap and water mix too. I would not put anything oil-based anywhere near that radiator plastic if you can help it. My car that I had to replace that hose on is an N51, so the penalty of breaking that radiator neck is a radical walletectomy to replace the stupid N51 radiator.


I second or third replacing the "mickey mouse" flange while you are in there. Mine crumbled to the touch. Annoyingly, the reason I had to replace my radiator hose was that the nipple for the expansion tank hose broke off while I was replacing that hose pre-emptively, and that one was perfectly fine. Not brittle at all. Go figure.

[lowrydr310]

Originally Posted by krhodes1

I second or third replacing the "mickey mouse" flange while you are in there. Mine crumbled to the touch.

What's the lifespan on the plastic Mickey Mouse flange? I'm all about preventative maintenance especially on failure-prone items, but my 330 has a Genuine BMW hose with plastic MM flange that was replaced in early 2020 during a full cooling system overhaul. I haven't squeezed it, but wondering when I should consider switching to a metal one.

[kkasson]

Originally Posted by lowrydr310

What's the lifespan on the plastic Mickey Mouse flange? I'm all about preventative maintenance especially on failure-prone items, but my 330 has a Genuine BMW hose with plastic MM flange that was replaced in early 2020 during a full cooling system overhaul. I haven't squeezed it, but wondering when I should consider switching to a metal one.

I wouldn't worry about it - the genuine plastic one lasts at least 10 years in my experience.

[StradaRedlands]

Originally Posted by kkasson

I wouldn't worry about it - the genuine plastic one lasts at least 10 years in my experience.

Agree... you're good for a bit!

[e90yyc]

Looks like krhodes1 has already said it but I’m going to say it again: Heat.

Using a heat gun to remove these fittings—night and day difference. No need to wrestle them off.

[mainbearing]

Check for discoloration (when it starts to get a hint of brown like your radiator connector, latte coffee like under the hose is a bit late). If it was from 2020 then it is still fine. You can wait until the next coolant change, which I typically do around 4 years. This would be the ~10 years others mentioned.

That said, since the cooling system is getting drained, might as well put a Metal Mickey on there. See also if the OFHG needs replacement. Put a Viton one on there if not already, bolts evenly torqued to 16 lb/ft IIRC.

Originally Posted by lowrydr310

What's the lifespan on the plastic Mickey Mouse flange? I'm all about preventative maintenance especially on failure-prone items, but my 330 has a Genuine BMW hose with plastic MM flange that was replaced in early 2020 during a full cooling system overhaul. I haven't squeezed it, but wondering when I should consider switching to a metal one.

[lowrydr310]

Originally Posted by mainbearing

See also if the OFHG needs replacement. Put a Viton one on there if not already, bolts evenly torqued to 16 lb/ft IIRC.

Oh that's all fresh, they were all replaced in 2020 along with all radiator hoses, radiator, water pump, thermostat, etc.

I did a similar refresh on my 335 in 2023, and replaced the MM flange with a Rein part. I learned the hard way that the O-ring supplied with the MM flange is junk because it started weeping coolant less than two years after installation. Coolant would leak out of the MM flange, run down the seam between the valve cover and head, then drip down right on top of the thermostat/water pump. I swore it was a thermosat/waterpump leak until I looked closely and followed the path. I replaced the flange with a "URO Premium" one and a Genuine BMW o-ring. The URO Premium flange is much better than the Rein flange.

[mainbearing]

Yeah, same here with the included Rein o-ring. It basically turned into hard plastic.

I happened to have a BMW o-ring on hand and just used that. Good reminder!

Uro Premium flange with lifetime warranty:
https://www.rockauto.com/en/moreinfo...GTs24KYA%3D%3D

[Black_Ls1]

You can also buy the MM flange from your local AutoParts store in the US. Its about 30 bucks with warranty

[GoRomeo]

Originally Posted by kkasson

I wouldn't worry about it - the genuine plastic one lasts at least 10 years in my experience.

Mine lasted almost 20 yrs in my N52.