Coolant flush, heater core holding old coolant?
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Mudding
Joined: Jun 2016
Posts: 208
Likes: 16
Coolant flush, heater core holding old coolant?
Hey guys quick question. I did a new radiator, hoses, etc. last night and completely "drained" the system using the lower engine coolant hose. I am worried that some dexcool stuff is still hiding in the heater core. Am I wrong to assume a cold flush will leave residual coolant in the system?
How do you know for 100% certainty all the dexcool is out? I would use distilled water but then I also have to consider distilled water remaining in the system too - or am I completely wrong? Does draining from the lower engine coolant hose flush the entire system.
How do you know for 100% certainty all the dexcool is out? I would use distilled water but then I also have to consider distilled water remaining in the system too - or am I completely wrong? Does draining from the lower engine coolant hose flush the entire system.
Pro Wrench
Joined: Dec 2016
Posts: 1,603
Likes: 229
From: Fall City, WA
No, it does not drain the entire coolant as the heater core is low and the hoses go down and up from the heater core.
The best way I have determined to do a flush is to actually use one of the heater core hoses and a garden hose. Pop off on side and push the garden hose in (with some kind of low diameter sprayer) and use low pressure. It will push out all the coolant till you get a steady stream of water. Do the same in the opposite direction.
There might be other ways but, this is what worked for me.
The best way I have determined to do a flush is to actually use one of the heater core hoses and a garden hose. Pop off on side and push the garden hose in (with some kind of low diameter sprayer) and use low pressure. It will push out all the coolant till you get a steady stream of water. Do the same in the opposite direction.
There might be other ways but, this is what worked for me.
Camel Trophy
Joined: Dec 2009
Posts: 3,883
Likes: 951
From: Charlotte
Here's what I do and what I recommend, although what Friday Night Disco suggested would also work. My method is time consuming but it's what I do.
Pull the lower hose off the radiator and drain the coolant. Refill with distilled water and bleed the system. Go drive a few miles, maybe 10. Repeat two times. By that point you've effectively diluted whatever was in the system to the point that it's virtually all distilled water. If you see any color in what's drained after the third cycle keep repeating until what's drained is clear with no trace or perhaps the slightest hint of color.
Once you're satisfied you have removed substantially all the old coolant and there's essentially nothing but distilled water in the system pull the hose off the thermostat that goes to the water pump and hold it down. That'll get more water out of the system.
Reconnect the two hoses and refill the system with antifreeze concentrate (not the 50/50 products). I use Prestone because it's readily available at Walmart and any auto parts store. I've done the math and done this a few times, and two gallons of full-strength antifreeze mixed with the distilled water in the engine, heater core, etc. gets the system to the desired 50/50 level. You may not get all two gallons of antifreeze in the system when you first add it, but after you drive the truck the coolant level in the reservoir will likely be down about an inch and you can then add the rest of the two gallons you bought.
And by the way, I've never had any problem bleeding the cooling system by carefully following the steps in the RAVE and making sure I do so only with the system cold.
Pull the lower hose off the radiator and drain the coolant. Refill with distilled water and bleed the system. Go drive a few miles, maybe 10. Repeat two times. By that point you've effectively diluted whatever was in the system to the point that it's virtually all distilled water. If you see any color in what's drained after the third cycle keep repeating until what's drained is clear with no trace or perhaps the slightest hint of color.
Once you're satisfied you have removed substantially all the old coolant and there's essentially nothing but distilled water in the system pull the hose off the thermostat that goes to the water pump and hold it down. That'll get more water out of the system.
Reconnect the two hoses and refill the system with antifreeze concentrate (not the 50/50 products). I use Prestone because it's readily available at Walmart and any auto parts store. I've done the math and done this a few times, and two gallons of full-strength antifreeze mixed with the distilled water in the engine, heater core, etc. gets the system to the desired 50/50 level. You may not get all two gallons of antifreeze in the system when you first add it, but after you drive the truck the coolant level in the reservoir will likely be down about an inch and you can then add the rest of the two gallons you bought.
And by the way, I've never had any problem bleeding the cooling system by carefully following the steps in the RAVE and making sure I do so only with the system cold.
Thread Starter
|
Mudding
Joined: Jun 2016
Posts: 208
Likes: 16
Here's what I do and what I recommend, although what Friday Night Disco suggested would also work. My method is time consuming but it's what I do.
Pull the lower hose off the radiator and drain the coolant. Refill with distilled water and bleed the system. Go drive a few miles, maybe 10. Repeat two times. By that point you've effectively diluted whatever was in the system to the point that it's virtually all distilled water. If you see any color in what's drained after the third cycle keep repeating until what's drained is clear with no trace or perhaps the slightest hint of color.
Once you're satisfied you have removed substantially all the old coolant and there's essentially nothing but distilled water in the system pull the hose off the thermostat that goes to the water pump and hold it down. That'll get more water out of the system.
Reconnect the two hoses and refill the system with antifreeze concentrate (not the 50/50 products). I use Prestone because it's readily available at Walmart and any auto parts store. I've done the math and done this a few times, and two gallons of full-strength antifreeze mixed with the distilled water in the engine, heater core, etc. gets the system to the desired 50/50 level. You may not get all two gallons of antifreeze in the system when you first add it, but after you drive the truck the coolant level in the reservoir will likely be down about an inch and you can then add the rest of the two gallons you bought.
And by the way, I've never had any problem bleeding the cooling system by carefully following the steps in the RAVE and making sure I do so only with the system cold.
Pull the lower hose off the radiator and drain the coolant. Refill with distilled water and bleed the system. Go drive a few miles, maybe 10. Repeat two times. By that point you've effectively diluted whatever was in the system to the point that it's virtually all distilled water. If you see any color in what's drained after the third cycle keep repeating until what's drained is clear with no trace or perhaps the slightest hint of color.
Once you're satisfied you have removed substantially all the old coolant and there's essentially nothing but distilled water in the system pull the hose off the thermostat that goes to the water pump and hold it down. That'll get more water out of the system.
Reconnect the two hoses and refill the system with antifreeze concentrate (not the 50/50 products). I use Prestone because it's readily available at Walmart and any auto parts store. I've done the math and done this a few times, and two gallons of full-strength antifreeze mixed with the distilled water in the engine, heater core, etc. gets the system to the desired 50/50 level. You may not get all two gallons of antifreeze in the system when you first add it, but after you drive the truck the coolant level in the reservoir will likely be down about an inch and you can then add the rest of the two gallons you bought.
And by the way, I've never had any problem bleeding the cooling system by carefully following the steps in the RAVE and making sure I do so only with the system cold.
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