In doing a coolant change in my GX470 I understand to turn the heat on before draining so "all" the coolant will be able to drain from the heater core. SInce the rear of this SUV has a separate heater, should I turn on the heater to the rear of the car as well in order to more completely drain more coolant from that area? I'm thinking I should.
Does Rear Heater Need to be On?
- Thread starter Gebo
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That sounds right, I would probably lift the rear a little also.
iis there a water shut off valve for the rear heater?
I used to turn the rear heater on in my 1990 Toyota 4 Runner when I drained/changed the coolant. It was mechanical, so moving the heat selector opened a valve. I would imagine that yours is electronic - so I have no idea if turning the heat on actually opens the valve with the car off during a coolant change...I might leave the ignition on to keep that valve in position...
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Originally Posted by Astro14
I used to turn the rear heater on in my 1990 Toyota 4 Runner when I drained/changed the coolant. It was mechanical, so moving the heat selector opened a valve. I would imagine that yours is electronic - so I have no idea if turning the heat on actually opens the valve with the car off during a coolant change...I might leave the ignition on to keep that valve in position...
I will wait until the heater blows hot air. You have a point in leaving the key on for a few minutes. It may not be necessary but what can it hurt?
I used to turn the rear heater on in my 1990 Toyota 4 Runner when I drained/changed the coolant. It was mechanical, so moving the heat selector opened a valve. I would imagine that yours is electronic - so I have no idea if turning the heat on actually opens the valve with the car off during a coolant change...I might leave the ignition on to keep that valve in position...
I will wait until the heater blows hot air. You have a point in leaving the key on for a few minutes. It may not be necessary but what can it hurt?
Do what you like to clear it out, but I rely on a drive with distilled water in the rad to clear out the rear heater by having the front and rear heat on. Then drain the system and if you like, fill the rad a second time with distilled water and take another drive with the rear and front heat on. Just make sure you finally fill the rad with 100% coolant rather than the 50/50. Test the coolant with a coolant tester (10 bucks at any auto store.) If you need more coolant, turkey baste the coolant out of your overflow jug and add more 100 % coolant until you get the concentration right. Works for me.
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Originally Posted by Gebo
This system uses Toyota 50:50. Can't really do what you are suggesting.
Toyota is insane. They probably charge the same price for 50/50 as others do for 100%. Also, Toyota doesn't want you working on your car.
This system uses Toyota 50:50. Can't really do what you are suggesting.
Toyota is insane. They probably charge the same price for 50/50 as others do for 100%. Also, Toyota doesn't want you working on your car.
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Depends how it's plumbed
Physical valve on the hose that prevents coolant flow? Crank it to max. Is it the newer style where the heater cores flow all the time and temp is controlled via blend doors? Doesn't matter. Though it is helpful to have it running a little bit so you know when all the bubbles are out
Physical valve on the hose that prevents coolant flow? Crank it to max. Is it the newer style where the heater cores flow all the time and temp is controlled via blend doors? Doesn't matter. Though it is helpful to have it running a little bit so you know when all the bubbles are out
Who uses 100% pure undiluted coolant ? Coolant is made to be mixed with distilled water or it won't do it's job properly, unless you buy pre mixed like Toyota Super Long Life. In U.S it's pre mixed 50-50, in Canada 55-45. Even if I were mixing my own I would never go over 60-40.
The issue is, if you do a flush with water, and then add 50/50 pre-diluted coolant, you will never get to 55-45 or 60-40 mix. It will be more water than coolant.
Originally Posted by madeej11
Who uses 100% pure undiluted coolant ? Coolant is made to be mixed with distilled water or it won't do it's job properly, unless you buy pre mixed like Toyota Super Long Life. In U.S it's pre mixed 50-50, in Canada 55-45. Even if I were mixing my own I would never go over 60-40.
Originally Posted by madeej11
Who uses 100% pure undiluted coolant ? Coolant is made to be mixed with distilled water or it won't do it's job properly, unless you buy pre mixed like Toyota Super Long Life. In U.S it's pre mixed 50-50, in Canada 55-45. Even if I were mixing my own I would never go over 60-40.
I can't think of anyone that would do that.
Who uses 100% pure undiluted coolant ? Coolant is made to be mixed with distilled water or it won't do it's job properly, unless you buy pre mixed like Toyota Super Long Life. In U.S it's pre mixed 50-50, in Canada 55-45. Even if I were mixing my own I would never go over 60-40.
Originally Posted by madeej11
Who uses 100% pure undiluted coolant ? Coolant is made to be mixed with distilled water or it won't do it's job properly, unless you buy pre mixed like Toyota Super Long Life. In U.S it's pre mixed 50-50, in Canada 55-45. Even if I were mixing my own I would never go over 60-40.
I can't think of anyone that would do that.
Well Snag, guess you'd better flush out all the water completely then. I don't get it, if a customer walks into any garage for a cooling system flush and fill, guaranteed if the job is done correctly his cooling system won't contain pure undiluted coolant when he drives away. C'mon man...
Originally Posted by Gebo
Originally Posted by Snagglefoot
The issue is, if you do a flush with water, and then add 50/50 pre-diluted coolant, you will never get to 55-45 or 60-40 mix. It will be more water than coolant.
Amen!
And unless you live somewhere where it gets to -30C or colder it likely would not matter if you ended up with a 40/60 or 45/55 mix.
Some coolant manufacturers say 30% is all you need for adequate protection from corrosion.
Where i live almost nobody runs 50/50, at auto parts stores you will most commonly find 10,20, 30 and 50% premixes, and some, but few stores carry concentrate.
And the price of 50/50 premixed coolants here are usually about twice of the 30/70 or 20/80
Originally Posted by Snagglefoot
The issue is, if you do a flush with water, and then add 50/50 pre-diluted coolant, you will never get to 55-45 or 60-40 mix. It will be more water than coolant.
Amen!
And unless you live somewhere where it gets to -30C or colder it likely would not matter if you ended up with a 40/60 or 45/55 mix.
Some coolant manufacturers say 30% is all you need for adequate protection from corrosion.
Where i live almost nobody runs 50/50, at auto parts stores you will most commonly find 10,20, 30 and 50% premixes, and some, but few stores carry concentrate.
And the price of 50/50 premixed coolants here are usually about twice of the 30/70 or 20/80
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Originally Posted by madeej11
Well Snag, guess you'd better flush out all the water completely then. I don't get it, if a customer walks into any garage for a cooling system flush and fill, guaranteed if the job is done correctly his cooling system won't contain pure undiluted coolant when he drives away. C'mon man...
Madeej, you and I are not connecting. After a flush done with water ( which all shops use to flush), if you add coolant from a 50/50 jug, mathematicallly, you will never have more than 50 % coolant. I find, after running water through the engine and heater cores, both front and rear, there is so much water left in the system, you can fill your radiator with straight 100 % coolant and come out fairly close to 50/50 at the end, as measured with density based measuring tool. The results will vary depending on the vehicle design. I have done this with four vehicles that have front and rear coolers, numerous times.
Well Snag, guess you'd better flush out all the water completely then. I don't get it, if a customer walks into any garage for a cooling system flush and fill, guaranteed if the job is done correctly his cooling system won't contain pure undiluted coolant when he drives away. C'mon man...
Madeej, you and I are not connecting. After a flush done with water ( which all shops use to flush), if you add coolant from a 50/50 jug, mathematicallly, you will never have more than 50 % coolant. I find, after running water through the engine and heater cores, both front and rear, there is so much water left in the system, you can fill your radiator with straight 100 % coolant and come out fairly close to 50/50 at the end, as measured with density based measuring tool. The results will vary depending on the vehicle design. I have done this with four vehicles that have front and rear coolers, numerous times.
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And unless you live somewhere where it gets to -30C or colder it likely would not matter if you ended up with a 40/60 or 45/55 mix.
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Hello FordCapriDriver. You are correct. Unfortuneatey, it does get to below -30 here, so let's put that caveat on all of this and switch gears. Depends where you live or where you are intending to drive. Also, the 50/50 Coolant sells for 80% of the price of 100 % coolant which is a rip off. Anyway enough said. Everyone do whatever they like.
And unless you live somewhere where it gets to -30C or colder it likely would not matter if you ended up with a 40/60 or 45/55 mix.
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Hello FordCapriDriver. You are correct. Unfortuneatey, it does get to below -30 here, so let's put that caveat on all of this and switch gears. Depends where you live or where you are intending to drive. Also, the 50/50 Coolant sells for 80% of the price of 100 % coolant which is a rip off. Anyway enough said. Everyone do whatever they like.
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