Ford Lehman heat exchanger

The friendliest place on the web for anyone who enjoys boating.
If you have answers, please help by responding to the unanswered posts.

kyle911

Veteran Member
Joined
Oct 5, 2014
Messages
68
Location
Canada
Vessel Name
Maurader
Vessel Make
Marine Trader Trawler
Quick question. Does anyone have a step by step process on how to remove the heat exchanger off a Ford Lehman 120? I have to get it pressure tested.

Also my seacock is more of just a bolt than a valve. Is there an easy way to tell if it's open or closed?
 
How old is the heat exchanger? On the Ford Lehman, it is considered a replacement item. We have a FL SP135 and have been told to replace it ever 10-15 years. On line, made of CuNi, they are less than $600.
 
For the seacock just back off a hose clamp and see if water is running or not.


Sent from my iPhone using Trawler Forum
 
Last edited:
Why pressure tested?


Sent from my iPhone using Trawler Forum
 
I found an old heat exchanger on board for my SP135. Through the Little peep hole it looked nasty. Took it to a radiator shop and $75 later 2tubes replaced, boiled out, rodded out, painted, looks new. Now I have a spare.
 
Kyle, close your raw water intake, remove end plates on exchanger (maybe a gallon of water?). determine where you wish to unhook and drain engine coolant(approx 2 gallons). at this point you probably have to remove the transmission cooler to remove the 2 bolts holding the main heat exchanger. As long as you have two coolers off you might as well take off the oil cooler as well, and open your raw water pump and check/ change impeller. Inspect all three heat exchangers, clean, replace, boil out as needed, replace hoses as needed, etc. Also if you have the old stye 2 piece raw water pump and many engine hours you might think of inspecting the wear of the drive tangs...four bolts holding the two halves together. If they are worn you need to replace the pump, approx $500 from American diesel :facepalm: One more thing to do is replace the thermostat under the expansion tank as you now have the entire engine cooling system torn apart. See how simple that is?:rofl: I just did all this about a month ago so now Im good for a while.
The other choice would be to do this in the fall when you are ready to put the boat away rather than now when you probably would rather be boating:). If you are worried about your heat exchanger you can inspect and flush it without having to remove it from the boat. Simply remove the plates on both ends and clean, flush rod out with soft dowel,etc, after making sure your seacock is closed. Hope this helps,
Bruce
 
Thanks for the replies!

Here's the seacock. Any ideas?

ydpYE
 

Attachments

  • image.jpg
    image.jpg
    137.4 KB · Views: 215
Last edited:
My thru hull valve looks like that photo. When the flat portion is across the valve it is off. With the flats aligned with the hose it is on. Yours looks like it is about 1/2 on (or 1/2 off). Mine has been drilled and a long bolt inserted to make a handle. If you don't do that, you can hang a wrench nearby so that in an emergency, you can quickly shut off the water.
 
There's an actual notch on the bolt. The notch runs the same way as the hose , it's open. If it runs across the hose, it's closed. Now I'm just trying to figure out which way to move the bolt to close it
 
Greetings,
Mr. k. Handles for these sea cocks should be available. I need a 1" handle myself but for the life of me, have been unable to source. You might try a gas fitting supplier...
 
How about a 1/2 inch drive square socket and 12 inch breaker bar, maybe 3/8 might be big enough.
 
Back
Top Bottom