Lehman 120 Fresh Water Hose Routing

The routing from the fresh water pump to the heat exchanger runs parallel with and just below the valve cover. Here's my question. Why is the connection between the two with two short (2 inches?) pieces of hose mated to a long metal tube? Why not just a long hose? I am about to replace my 20-year-old heat exchangers and I remember when I had the exchangers off two years ago to clean them it was difficult to get that assembly together. A longish somewhat flexible hose would be easier it seems. Is it a chafing issue somewhere along the way? If so, that shouldn't be difficult to mitigate. The picture is a bit out of focus but it depicts what I am talking about. I also wonder why the metal tube behind the injection pump can't also be eliminated but that would require a molded elbow and long run to the heat exchanger. Thoughts?

I ran a length of hose and eliminated the piece of copper 500 hrs ago and 3 round trips to FL from Jersey.....no issues except supporting it needed a bracket made and there is a chance of chaffing...but overcome and keep an eye on it.


It's a lousy design behind the injection pump but manageable. I kept the short piece there to connect to the pre-bent from the expansion tank.

Thanks for the quick response and picture. The short piece, that makes sense. I see that you eliminated the OEM filter bracket. Nice. Question. What thread fitting did you use on the injection pump?

psneeld said:

I ran a length of hose and eliminated the piece of copper 500 hrs ago and 3 round trips to FL from Jersey.....no issues except supporting it needed a bracket made and there is a chance of chaffing...but overcome and keep an eye on it.


It's a lousy design behind the injection pump but manageable. I kept the short piece there to connect to the pre-bent from the expansion tank.

Click to expand...

catalinajack said:

Thanks for the quick response and picture. The short piece, that makes sense. I see that you eliminated the OEM filter bracket. Nice. Question. What thread fitting did you use on the injection pump?

Click to expand...

Not sure what you are asking?


Thread fitting on injector pump ...hose to pump?


To tell the truth I dont have the number in my head or written down...I just took the old fitting to a hydrauliccs shop and got what I needed for my application.


I am more of an operator than a mech...I just keep the boat going...can't remember the tech stuff... ...but I can draw the trip from NJ to FL from memory prett well.