300 E 2.6 Water by-pass hose

[James Hageman]

Greetings to Everyone,
I have a 1991 300 E 2.6 in perfect condition. I have a small water leak in the by-pass hose that goes from the thermostat housing into the block. When I called the parts counter to order the hose they told me it was a three hour job to replace it as the whole water pump has to come off. Can this be true?
As I stare at this 2 inch piece of hose with two clamps on it, I just can't visualize how it would take dismanteling the water pump housing.
I would respectfully request some opinions before I remove the hose and find that I am unable to put the new one on by myself.

Thanks for your help.
Jim

 

[tom7035]

Hi James. I'm not familiar with the 300E but it is likely there isn't enough room between the block outlet and the housing inlet to squeeze the hose in between the two. This will be why the pump may have to be unbolted first. I had this scenario on something I previously owned many years ago but can't remember what. Only a thought mind you, hopefully someone will come in & say this isn't the case.
Good luck, Tom.

 

[996jimbo]

I remember having exactly the same problem on a mini a good few years ago. I'm not at all familiar with your car but it sounds similar. The problem is that the hose slips over a metal tube at either end (obviously) and there is little clearance between the ends of the two tubes, assuming that yours point directly at one another. On a mini the awkwardness is further exasperated by there being no room around the water pump to operate. Anyway, the long and short of it was that I completely destroyed the old bypass hose getting it off and after much swearing and scraping of knuckles did get the new one on - but it was a real fiddle. If you get the replacement hose hot before you start trying to fit it that makes it more flexible. Of course once you remove the old one you have to complete it as you can't then drive to a garage!

The mini hose I remember had a slight 'concertina' shape so may have been designed to be able to be fitted in situ without further dismantling of the water pump. In fact thinking about it I'm sure the bypass hose only fitted to the water pump, not between the water pump and another part. With yours you might want to heat up the existing hose and then squeeze it to try and establish what clearance you have between the two tubes and therefore whether you think you can get the new hose on to both ends without separating the two components.

 

[nicky]

This is probably true as there is not enough room to slide the hose off both ends,i have seen this before and you will need to remove the water pump to fit the hose..

 

[Myros]

going a bit lateral

would it be possible to fit a much longer hose of the same diameter, but loop it around. Motor factors do sell concertina hose in various dias and lengths. If there is room to do it, it might be worth a think. The old lag's trick of smearing a bit of washing up liquid neat inside the ends of the hose and on the pipes you are fitting it to will help it go on as well.

 

[tom7035]

You're no further forward there Myros, if you were able to fit a longer hose you would be able to fit a shorter one! As 996jimbo says, the problem will be the lack of space between the ends of the two metal tubes which the hose connects.

 

[Myros]

I wish I could do a Vulkan mind-meld

I was thinking the longer one could displace itself left and right and sort of squeeze past itself in the bit between the pipes.

 

[Richard Moakes]

I changed the water pump on my 3.0 M103 a year back, and I remember that hose well.

I changed it at the same time, even though the old one was perfect. I can confirm the water pump has to be removed to change it.

Richard

 

[James Hageman]

Jim Hageman

EVERYONE,
Thanks for your input on the hose replacement. It's obviously going to take some heavy thought and a couple of beers before I take the plunge and shred the old hose trying to remove it. Then...who knows.
If it were only as easy to work on as my MGTD which can be dismanteled completely in a few hours.
Thanks again,
Cheers

 

[davidsl500]

I remember having exactly the same problem on a mini a good few years ago. I'm not at all familiar with your car but it sounds similar. The problem is that the hose slips over a metal tube at either end (obviously) and there is little clearance between the ends of the two tubes, assuming that yours point directly at one another. On a mini the awkwardness is further exasperated by there being no room around the water pump to operate. Anyway, the long and short of it was that I completely destroyed the old bypass hose getting it off and after much swearing and scraping of knuckles did get the new one on - but it was a real fiddle. If you get the replacement hose hot before you start trying to fit it that makes it more flexible. Of course once you remove the old one you have to complete it as you can't then drive to a garage!

The mini hose I remember had a slight 'concertina' shape so may have been designed to be able to be fitted in situ without further dismantling of the water pump. In fact thinking about it I'm sure the bypass hose only fitted to the water pump, not between the water pump and another part. With yours you might want to heat up the existing hose and then squeeze it to try and establish what clearance you have between the two tubes and therefore whether you think you can get the new hose on to both ends without separating the two components.

On the mini the top of the bypass hose went to the cylinder head. The rubber hose had a centre concertina section so that it would compress down. Had a lot of minis in my youth and was taught the easy way to change them. Cut the old one off. Grease the ends and place the lower end in place, borrow a nice thin steel spatula from the kitchen and place over open end, push down and move hose into position and slide spatula out - takes 2 minutes on a mini.

Note : I dont think this would work on the Merc unless the tube had a concertina section to it - 2" of solid hose just dont compress far enough down. Might be worth checking the tube diameter and length to see if the mini hose would do it?

 

[paulcallender]

...and to take the water pump off, you need to remove the fan
...and to remove the fan, the radiator has to come out
...and when the radiator comes out, you have to disconnect the auto transmission cooler pipes
...so you have to drain the auto transmission fluid
...and there's an oil cooler too, right?

You see where this is going? I guess it due to the nature of the engine being in-line. The water pump will be positioned either at the front or the back of the engine (could be worse! could be at the back!!!) rather than a transverse engine having it one side or the other.

I remember changing a water pump on a Fiesta - very easy job. Then I came to try the same job on a Peugeot 505.....yukky job!