KillBillz

So I walk out to my car and see all my coolant on the ground. After putting the car on ramps I see my right side coolant hose has separated. The clamp that is supposed to be holding it together it looks non reusable and crimped from the factory. In a pitch I purchased a hose clamp from the auto store ( one that you tighten with a screwdriver ) and refilled with Pentosin NF. No leaks in the few miles that I had to drive the car to an auto body shop ( someone side swiped me).


So my question is... should I leave the auto parts clamp or replace the entire hose ?? Going to attach a pic of the hose in question. Will also circle the area I repaired.

belarus27

In my opinion should be pretty secured if the right size was used.

kajtek1

Having lot of garden hoses around, I can tell that crimp connectors on rubber hoses suck big time.
The rubber tends to shrink over the time and unless it is very strong crimp- that will begin to leak.
I don't see anything wrong with worm drive clamps, that work on cars for decades, especially when MB hoses start costing in hundred$$$
But still good inspection is advised. Loose connector coming apart without previous leaking raise a brow.

KillBillz

Yeah I believe what I installed was what youre referring to as a worm drive clamp. I have never seen any coolant leaks or oil leaks at all. My car was recently serviced at Mercedes Benz of Manhattan for the 70K transmission fluid change. While I was there they tried to tell me that I had a major oil leak coming from some engine gasket (had 16 bolts). All i could think about is the little bit of oil that spilled when I changed the oil a week before. I jacked it up a few days after that and not a drop of oil anywhere.... checked again a week later , still dry. Definitely raising a brow now.

I think I might order the hose and have it on standby. Its $120 which is not that bad

KEY08

You’ll be fine.

kajtek1

Most of them are made with stainless steel, but make sure about it.
The only weak point, especially on smaller sizes is the bend under the screw that might have different radius than the hose and develop small drip there.
Easy to avoid by putting 2 clamps with screws in different points.
Mercedes used them till late 1990's, when they switched to crimps for faster assembly.

MercFiveHundred

Same exact thing happened to me. Right after the 70k fluid. Has to be something they do to break it.

KillBillz

Thanks for the reply. Yes the one I purchased was stainless steel. Unfortunately for me to add an additional clamp , I would have to dump all the coolant. Plus I dont think there is enough space for 2.

KillBillz

Thats a crazy coincidence. Hopefully they arent doing something to cause this issue

KEY08

These fasteners can be opened completely and placed around the hose, so you wouldn’t have to pull the hose off the connector. Then just pushed the end into the tab and start screwing it. Doesn’t look like there is room for two as you have said, however.

KillBillz

You're absolutely right. I'll take a look when I get my car back from the body shop. Maybe I can move the other one off center to fit a 2nd clamp.

Arrie

One hose clamp should be plenty strong to hold this very low pressure hose in place. I work in industry where a vast number of hose clamps are used and they hold fine at much higher pressures if tightened correctly.

But, in this industry I learned that a regular stainless steel hose clamp is not really that. The band itself is stainless but the screw Is not!!!

Because of this I have seen very many clamps fail just because the screw corroded away.

Completely stainless steel hose clamps must be, at least in industry locations where I work, special ordered to have also the screw Made of stainless steel.

I don't know where you got the clamp and perhaps it is all stainless but a simple magnet test on the screw will tell.

MercFiveHundred

Not sure what you mean but not a high pressure hose. I was sitting in my parked car when the hose ‘blew’ off. It was very loud and shook my car.

Arrie

It makes noise and lots of liquid comes out but it is not a high pressure hose compared to some industrial installations I compare to that are held by hose clamps.

Stuttgarten

I'd go with a spring clamp, there's a reason why factory didn't use worm clamps. Here's a nice short article on why a worn clamp is "inferior."

https://axleaddict.com/auto-repair/C...lt-Hose-Clamps

kajtek1

You did notice how the author is B***ing about worm clamps, but highly prize racing clamps?
They both operate on the same principle of fixed tension from the screw and have the same weak points.
Racing clamps has no slots cut in it, so at this aspect is superior, but the slots don't seem to be a problem in proper application.

crazybear

I'd hate to bring this thread back from the dead, but I'm having the same issue. The hose separated and I reinserted it and installed a worm clamp. Yesterday, all the coolant has spilled out, which I'm assuming I didnt tighten the clamp enough, but havent gotten a chance to check yet. Does anyone know the part number of this hose?

KillBillz

Here is the part number (212-501-26-82) for my 2014 E550 but I would still verify if its the correct one for your car. Its considered the right coolant hose or lower hose. I hate the change they did with the parts catalogs. Makes it much harder to find the correct part , but every site has the same setup. I used https://www.mercedespartscenter.com/

crazybear

Thanks KillBillz. Did you end up replacing the hose or did the worm clamp hold up?

KillBillz

So far the clamp is holding up. My longest trip so far has been my move from NYC to Northern VA.

mtnman82

The plastic tubes in these (Mercedes) cooling systems of are notorious for cracking/failing. Crazybear - the plastic connecting piece may be cracked, or may have gotten cracked if the worm clamp was over tightened.

I've used the worm clamp many times to replace the snap clamps. Never had an issue. Even with the correct tool for one of those clamps they're still a pain to use IMHO.

KillBillz

So how did your hose situation turn out? Did you replace the hose or use a clamp? Im running over a year and 10k plus miles using a worm clamp. I should get under there and check it tho

crazybear

I ended up having to replace the hose. it wasnt too bad, just had to be patient to wiggle into place. I just couldnt get the clamp to work; maybe I didnt tighten it enough or the plastic part was warped.

KillBillz

Or maybe too tight. Anyway im glad you were able to sort it out. Probably a $1000 job at Mercedes.

KillBillz

So after 2 years and 17K miles the hose disconnected and dumped my coolant out again. I didnt get under the car just yet but the clamp is still intact but seems to have worked it way off of the plastic junction. Going to fix it properly this time