engine flush

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gonesailing13

Senior Member
Joined
Jul 2, 2013
Messages
148
Location
usa
Vessel Name
Graceful
Vessel Make
Marine Trader
Can anyone tell me how to flush the coolant on my Lehman135. Doubt if the previous owners ever did this and would like to start fresh , however not sure how to drain and go about it. Thanks in advance.:confused:
 
Not sure about that engine but the least intrusive way is removing the lower hose off the circulation pump. It doesn’t get it all out but you also don’t break anything
 
Are you changing the coolant or doing a real flush? If it's in salt water you should be doing a raw side cleaning with Rydlyme or Barnacle Buster. There should be a plug on the side of the block, low down that drains the head and block. If you buy a valve and hose fitting to fit the plug, it makes it easier next time.
 
I have SP225s and changed the coolant last year for the first time. I just drained the coolant and refilled since the PO did do routine maintenance on them. I did not use any flushing agent because the coolant had been changed regularly. If you are not sure how to do it exactly call Brian Smith at American Diesel. 804-435-3107
 
My diesel mechanic suggested that I simply shut-off my raw water intake, run the engine and pour the Rydlyme (mixed 50/50 with water) into my raw water strainer. He said once I get about 5 gallons into the system, shut off the engine and let it sit for 4 hours, then run the engine to clean out the system.

Has anyone had any success with this method?
 
I used Barnacle Buster in my engines with the let it sit method. I put it in and let it sit for 7 hours per BB directions. Started the engines and let it flush out. One engine dropped 5 degrees and the other one dropped 10 degrees from what they always ran at. So I say yes it worked.
 
I have a "T" installed in the heater hose on my Lehman 120 with a valve and hose connection.

I suck out the coolant with a reversible pump connected to the "T". Reversing the pump, I fill the block with water and a flushing liquid.

Run the engine a while till it reaches operating temp, shut off, let cool, suck out the water.

Then I have an adapter that attaches a clear hose to the fill neck to allow water to exit the engine without spilling all over. I hook water hose to the "T" and keep water running at full pressure while water exits fill neck. I take turns pinching the hose on either side of the "T" every 5 minutes or so to change the direction of the flush.

When no more solids and rust colored water exits the hose connected to the fill, start the engine with water hose still running. More rust and solids should come out. Continue pinching the hose on either side of the "T" until exiting water is clear.

Suck out water from engine and fill with antifreeze and distilled water or a premixed anti freeze.

I change antifreeze every 5 years and flush every 10.
 
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Can anyone tell me how to flush the coolant on my Lehman135. Doubt if the previous owners ever did this and would like to start fresh , however not sure how to drain and go about it. Thanks in advance.:confused:

If you're talking about the antifreeze, the 135s have drains on the lower port sides of the blocks - just a little forward of center. Opening these will get it all out. You can attach a 1/4 ID drain hose to the valve. If you have the hot water heater connected to the engine loop it's possible one of the hoses is connected there. Mine has a T at that spot so there is still a drain valve.

Note they take 5 full gallons to fill after a complete drain.

Ken
 
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