I'll start with a picture. As to the setting, think 95 degrees in the middle of the afternoon, north of Mono Lake off 395 in CA on the east side of the Sierra, me holding the hose in one hand and taking the picture with my cell phone in the other after finding the source of the problem....
What you are looking at is the failed Snap Lock fitting located on the bottom of the radiator on the passenger side of the van. When this failed, it failed fast and it was a good thing that we saw the warning messages on the dash quickly. Our immediate reaction was to shut down the AC, turn on the heat, and watch the temperature display as we made our way off the dirt track we were on and got back to gravel. It's a good thing we were on our way back and were close to the road when this happened!
The immediate result was that Flint got his first tow, this after four years and 60+k miles of trouble-free service.
So what happened? I carry hose repair tape, hose clamps and enough water to fill the radiator, but my experience (before this) did not extend to this type of Snap Lock fitting. Think of a precision female receiver on the radiator with a matching precision male fitting on the hose, an O-ring in between and a three-sided exterior spring that holds it all together....
The van went to MB of Reno to be repaired. Good shop, I have no complaints with the service. According to them, they have never seen a failure of this type before.
Speaking to Dennis of Linden Engineering over on the Sprinter forum, he says this is something they are seeing back in CO on what is becoming a regular basis, and that the fault lies with the spring clip loosing its spring tension over time. He has started to replace the spring clip as a routine item every third service (the service Flint had about a thousand miles BEFORE this happened...)
From the MB Reno paperwork: "
Found lower radiator hose disconnected. Reconnected hose, filled coolant, test drove, found lower hose slowly backing out of radiator and releasing coolant. Inspected radiator, found lower hose connection on radiator deformed. Drained coolant, removed air intake and grille. Removed and replaced radiator, lower hose and retaining clip. Filled and bled cooling system, test drove, confirmed proper operation".
Here is what both ends of the hose look like after the repair. Believe me, you have to look to find this particular attachment point! First the easier-to-see standard connection, followed by the Snap Lock Fitting connection to the radiator.
And here is the figure from the MB computer. The O-ring is item number 220, the hose is item number 200. Here are the part numbers:
906-501-20-82 A HOSE
000-993-08-02 A SPRING
Per Dennis, the spring clip can be changed from the exterior without disturbing the O-ring seal. Based on my use this is now something I will add to my regular maintenance schedule and this clip will get changed out every 3 years. I have a couple of them on order right now and one will be added to my on-board spare parts kit.
And here is a link to see what the offending spring clip looks like and costs:
https://www.mboemparts.com/oem-parts...ing-0009930802
All-in-all, this is just part of the experience and I got a nice train ride back and forth to Reno as part of it. But I don't want me, or any of you, to have to repeat the experience, thus I suggest we all learn more about this particular item and prepare accordingly!