I would guess that MB timed it so if this hose needed replacing then so did the water pump. There is also an O ring between the water-pump and engine block that gets hard.

AS the vehicle is nearly twenty years old, you should replace water pump, thermostat, tensioner, belts and hoses. (flush radiator)

without removing the water pump in my 300e. Yes, I cut the hose and installed the new one through the gap. The secret is buying the hose from the dealer as it is more flexible than after market. You will need lubrication and a lot of patience but, it will get in there. Worse comes to worse, you will need to remove the water pump. By the way, if you need to cut the pipe, make sure it is on the water pump side.

Good luck!

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J.H.
'86 300E

thanks.

by the way, why on the pump side? i was thinking of cutting the pipe on the block side. seems long enough.

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1990 Mercedes 300 SEL (320,000 miles)
1994 Mercedes E420 (140,000 miles)

Seriously? You managed to slip the hose into that 1/4" gap? I thought even god can't do that. What kind of lubricant did you use (engine oil?). Can you give us some details? I think sooner or later I would have to replace that hose on my W124.

Thank you!!

I was able to get a hose on there without taking the water pump off.

What I did is I went down to Autozone and bought a hose and cut it 1/2 the length as the hose from the dealer.

I then sprayed the hose with liquid grease(from Gunk). To my surprise, it fit on with not too much difficulty. As because the length was shorter than normal, I used 3 clamps instead of 2.

So far so good.

I still have the new-stock hose from Mercedes and plan on replacing if and when the water pump eventually goes. I can't remember when I replaced that pump last so it must be awhile. To my surprise the Mercedes hose is quite thinner than the ones from Autozone. My hunch tells me that the ones at Autozone will last even longer if thickness = durability.

__________________
1990 Mercedes 300 SEL (320,000 miles)
1994 Mercedes E420 (140,000 miles)

what do you have to loose...?

__________________
J.H.
'86 300E

Is the hose from Autozone of two different diameter at each end? I was down this road recently and bought a hose from the dealer. The two ends has different diameter; one is larger than the other. I backed out of pulling the pump at the last minute so I still have the hose sitting in the closet somewhere.
So if the hose is the same diameter I wonder how you resolve the fact that the pipe from the engine block is different diameter than the pipe from the pump.
But I am glad you did it though, if I have to replace that hose I will attempt your method prior to pulling the pump.

No the hose from autozone was the same diameter throughout. but note, the diameters of the block pipe and water pump outlet are not that much different and not sure if the accuracy of hose diameters have to be that accurate to work.

In general, the key is to use 3 clamps instead of two. one on both sides, and one in the middle, over where the gap is.

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1990 Mercedes 300 SEL (320,000 miles)
1994 Mercedes E420 (140,000 miles)