The little hose that could
 

The little hose that could

I posted a request about replacing the bypass hose on a 300e. “Do I need to remove the water pump to replace the bypass hose?” “Is there a way to slip a new on?” I got several responses “pump Must Come off”. Then one gentleman said “I slipped a new on without removing the pump”. Of course that was the answer I wanted to hear. The real question was how much space is there between the water pump and the cylinder head inlet? Since someone was able to replace the hose without removing the pump I assumed there must be at least ½ inch.

I got the drain pan out and proceeded to open the drain plug. All was going well until I realized that ¾ of the coolant was dripping onto the splash pan and onto the garage floor. After cleaning up the mess on the floor I proceeded to remove the clamps holding the bypass hose and took a sharp knife and slit that sucker in two. Holy crap… 1/8 inch… the thickness of the hose. There’s no way this is going on there!

I reviewed the water pump removal and realized that I needed O-rings if I were to remove the pump. Well I might as well give it a try… I looked at the hose and I looked at the opening and shook my head. I started to push the small end on to the cylinder head outlet. Yes I can… I used a large blade screwdriver and pushed… Yes I can… Then I got a pair of water pump pliers and twisted, turned, twisted, turned, yes I can, yes I can.

My friend was wrong… No cursing no crying no sweat. That sucker slid on like a ski boot on sore feet on a Vermont afternoon. I stood straight up and looked down and smiled… Yes it will.

Thanks J.HIDALGO

J Hidalgo,

Did you get the correct part for the bypass hose? I'm asking because the correct part is a special transition hose. The water pump end is a different diameter from the head end. If the piece has an MB pn on it, you should be okay if you could see a slight difference in size between the ends. Some shops have unknowingly put a straight piece on there only to find a leak path over time because the one end is oversized.

HTH,

someguyfromMaryland

Yes I made sure I got the OEM part as you suggested. It took all of 10 mins to install.

J Hidalgo, I'm amazed you got it in through that tiny crack of a gap. I still can't imagine how you could possibly slip that chunk of hose into that sliver of a gap. I just changed the two other hoses on my 190E but my head told me not to remove the bypass hose once I saw the tiny gap when I slid the old bypass hose away from the gap. I'm totally impressed with that job I wussed out on.

-Andrew

Well guys, not to put a negative spin on all of these fine efforts, but, :( :( , all of these hoses are not designed to be twisted, poked and excessively stretched. I'm sure you can get the hose on, but I wouldn't bet much on the life expectancy of that item, especially if I were in a desert (or other hot place) and it was usder max pressure and heat. If you must use this type of repair, just cut 1/4 or 3/16 inch (or a bit more if you must) off the bypass outlet in the head with a hacksaw. Not elegant surely, but it will not harm anything and hose replacement will be a whole lot easier for you and less mechanically stressful for the little hose that could...;) ;) ..

Jeffsr

I though of the back yard mechanic approach and considered hacking the cylinder head but I worried about the filings.

I could be driving through the desert with a hose with no name… The filings would be on my brain.

Then the desert would remember those filings and run them into the water pump. The water pump would spin like an airplane propeller into the radiator. Then there would be no little hose that could…

Like you said Jeff “No matter what you fix, there will always be something else to fix..”

Hey Joe whadda know!!. Being an adroit backyard and other type mechanic, I would be coating the bypass outlet with a great glob of vaseline to catch all those little filings and such, wiping the whole thing down quite obsessively before inserting the little hose that could :D :D .. Personally, I would be removing the water pump to replace that little hose. A little more work perhaps, but, that little hose that could can really ruin your day if it lets go, especially at speed. You would be surprized how fast you can empty the cooling system when the little hose couldn't ;) ;)

A couple of years ago that little hose on my 103 was going south - As I was calculating in my head the amount of labor involved in removing the water pump to replace it , my mechanic turned away from the car looking for something. Out came the hacksaw, to my utter amazement and disbelief that is exactly what he was going after - that 1/4" " TAIL" coming out of the pump - Assuring me with a smile all will be good...
Can't be , I am thinking - If it was designed that way, there must be a reason...

Took all of ten minutes for the whole job and has been well since (in that department).