Coolant

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Gwkessel

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Fluid Motion Model
R-23 (Outboard)
Vessel Name
Andi Lee
What is the recommended time for a D6 Volvo PENTA engine coolant replacement
 
My recommendation is every 2 years. The Volvo manual gives a list of items that require service every 200 hour or once a year. Then states coolant change every second year. I take this as every 400 hours or every two years. That is how I have always serviced close cooling systems every two years antifreeze replacement. Marine age should always take precedence over engine hours. Meaning years first then hours. Unless you put 200 hours per year on the engine then use hours and fuel consumption as your gage.
 
Thanks BB,
Would you describe the best procedure for the D6,2016?
Thanks
G
 
Thanks Chimo
Not a lot of detail with that link
G
 
Gwkessel":gjdbfb35 said:
Thanks Chimo
Not a lot of detail with that link
G

My apologies. I didn't actually download and read the d6 owner's manual and I should have done. I assumed that the information provided would be the same as the d3 manual. That provides quite detailed instructions on change intervals and the procedure. Of course it's not perfect. As an example it suggests draining from the bottom of the heat exchanger. I recall that I solved that issue with a piece of plastic tube and a simple hand pump of the type used to fill the leg of an outboard. Hope this is more helpful.
 
Where did you insert tube and did you use hand pump to suck out coolant and collect in bucket? Did you flush heat exchanger and after cooler with distilled water,run engine,drain water and then refill with coolant?
Thanks
G
 
There should be two drain locations. The exchanger/after cooler and the block drain. The should be petcocks with nipples on them. Starting with the exchanger /aftercooler connect a hose ( I believe 3/8 ID hose) to the nipple the loosen the petcock to open it hose in bucket. Remove the expansion tank filler cap and drain the coolant. When the Coolers are completely drained close the petcock and install the hose to the block petcock nipple. Open this nipple with a bucket under the hose. When it is completely drained close the petcock. Now close both Hot-water heater ball valves . Remove the hose from the valves. Drain the coolant by blowing though or pumping fresh water (distilled )until the anti freeze is removed and clean water comes out. Pump new antifreeze through one hose until new antifreeze come out of the other hose. Reattach the hoses to the ball valves. Leave the ball valves closed.

If you elect to flush the engine block and exchangers fill the block using the Expansion tank filler. Fill with distilled water. Once it is filled start the engine and bring it up to temperature. Once up to temperature shut the engine down and let it cool until the coolant temperature is safe to work with. Repeat the exchanger /Block draining. When all the water is drained, petcocks closed fill the block (Expansion tank filler) until full. leave the cap of the tank to burp some of the trapped air. Install the cap after about 10 minutes and start the engine. Open the Hot-water tank ball valves. Run the engine up to temperature again. When it cools down check the antifreeze level at the expansion tank. Add if needed.
 
An excellent description Brian. On the R25SC the heat exchanger nipple sits only a couple of inches above the hull, ditto the block. That was the reason to use a hand pump to reach the bucket. I confess that I don’t bother with the hot water exchanger or flushing. When I measured what I had drained from the engine I had a good percentage of the capacity replaced.
 
Thanks Brian,
Not sure I understand this part or location of hot water ball valves on the D6
Now close both Hot-water heater ball valves . Remove the hose from the valves. Drain the coolant by blowing though or pumping fresh water (distilled )until the anti freeze is removed and clean water comes out. Pump new antifreeze through one hose until new antifreeze come out of the other hose. Reattach the hoses to the ball valves. Leave the ball valves closed.
G
 
I'm about to embark on this project, or maybe hire my mechanic to do it... I need to flush the coolant, flush the seawater system, and change the heat exchanger and aftercooler anodes...
 
Gwkessel":19ci86jq said:
Thanks Brian,
Not sure I understand this part or location of hot water ball valves on the D6
Now close both Hot-water heater ball valves . Remove the hose from the valves. Drain the coolant by blowing though or pumping fresh water (distilled )until the anti freeze is removed and clean water comes out. Pump new antifreeze through one hose until new antifreeze come out of the other hose. Reattach the hoses to the ball valves. Leave the ball valves closed.
G

There are two valves with heater hose going to the Hot water heater and bus heater. The valves are used as block valves in the event that a leak occurs in this coolant system. The engine antifreeze heats the exchanger in the hot-water heater and the bus heater. If you plan to do a complete flush of the coolant system it is a good idea to flush the water heater a bus heater and the hoses. If you are just changing fluid then it is probably not needed.

My thinking on this. If you flush the engine of all old coolant but you don't flush the side circuit hot water heater and bus heater. You are introducing old anti freeze back into the system . Don't bother flushing the block. Its kind of a all or nothing in my opinion.
 
I agree Brian
Just can’t seem to recall where these 2 water heater ball valves are located on the C30. Any clues. I will be on board
Later to follow up.
Thanks
G
 
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