Coolant Replacement Questions

[RoGuE]

I made a thread a while back but am finally ready to do this now, so I have a few more questions.

This is for a 2002 Suburban. I'm going to be replacing it with Dexcool. A few questions I have are:

I have a bottle of Prestone Dexcool that is a few years old. Should I just buy a new one or could this be okay to use?

What is the best method for replacement? It was last done 4 or 5 years and 50k miles ago. Is a full flush needed, or can I just do a few drain and fills with distilled water before filling with the coolant?

How do you mix it? I'm not sure I understand the mixture instructions. My Haynes manual says the cooling system holds 14.5 qts, then how many gallons of coolant and distilled water do I need to buy? And what mixture ratio should I use if I live in Georgia? Our temps range from as low as 15 in winter to over 100 in summer.

 

[Garak]

Originally Posted By: RoGuE
I have a bottle of Prestone Dexcool that is a few years old. Should I just buy a new one or could this be okay to use?


Thank you for that good question; I have the same question, and I don't mean to hijack your thread. I local Walmart finally has a stock of G-05 concentrate. I won't need it for a while, and am wondering about its shelf life, too. I simply don't know when it will be available again, and the Chrysler and Ford dealers want twice as much as Walmart does for the Zerex G-05.

 

[lipadj46]

As long as it was sealed it should be fine. I would do a full flush, pull the lower radiator hose or radiator drain valve which ever is easiest then (this is overkill but it is what I would do):

1) drain and flush with a garden hose,
2) drain and refill with distilled water and let it run til hot
3) optional repeat step 2 to get as much distilled water as possible in
4) drain and pour in 7 quarts of coolant, top off with distilled water if necessary.
5) Bleed if it does not have a radiator cap.
5) drive around for a while, let cool and top off with water if needed.

I would buy 5 gallons of distilled water and 2 gallons of coolant

 

[RoGuE]

I have read other place that even a garden hose shouldn't be used, only distilled water. But it is okay to use the hose as long as I flush it with a few gallons of distilled water afterward?

Also, a 50/50 coolant to water mix is okay for my climate?

 

[mechanicx]

Originally Posted By: RoGuE
I made a thread a while back but am finally ready to do this now, so I have a few more questions.

This is for a 2002 Suburban. I'm going to be replacing it with Dexcool. A few questions I have are:

I have a bottle of Prestone Dexcool that is a few years old. Should I just buy a new one or could this be okay to use?


It should be fine. Dexcool has a long shelf life, about 7 years at least.

Quote:
What is the best method for replacement? It was last done 4 or 5 years and 50k miles ago. Is a full flush needed, or can I just do a few drain and fills with distilled water before filling with the coolant?


There are several ways to go about it. Repeated drain and refills can be effective but it is very time consuming.Dexcool does have a long service life and you could just drain the radiator and refill with Dexcool premixed or diluted to 50/50 every 30-50k miles.

You could also do a full flush and remove the thermostat, temporarily reinstall the housing and upper hose but disconnected from the radiator and flush the system with a water hose. Or you could install a T-flush in the heater inlet hose. These methods will leave tap water in the system but I don't think this is a big issue. And you could open the block drains. You sort of have to judge for yourself which you think is the easiest way for you. But the T-flush is almost always the easiest.

Quote:
How do you mix it? I'm not sure I understand the mixture instructions. My Haynes manual says the cooling system holds 14.5 qts, then how many gallons of coolant and distilled water do I need to buy? And what mixture ratio should I use if I live in Georgia? Our temps range from as low as 15 in winter to over 100 in summer.


I would recommend 50/50 for maximum corrosion protection and coolant service life. If you are just draining the radiator then you need to mix the coolant 50/50 before adding. If you have flushed it with water one way or the other or drained the block, you should put 1/2 capacity of concentrate in so 7.25 qts then top with water.

As far as tap water, Dexcool is tolerant of most tap water. I don't know if you are using city or well water, but the South generally doesn't have hard water. Distilled water is more idea. If you use a T-flush or a garden hose to do a full flush, you could drain the radiator then close the drain and try to add full capacity of distilled water from a high point (usually the pressurized reservoir) with the T-flush cap off (or before reinstalling thermostat) to displace the tap water. You'd probably want to drain the radiator once more to make room for 1/2 capacity of concentrate.

Well I hope all that makes sense.

 

[HTSS_TR]

I use tap water from garden hose with T-flush in my '94 250+k miles LS400 without any problem, it still has original OEM radiator and lower Radiator hose. It just had the first upper hose and thermostat replaced last year, the water pump was replaced once about 100k miles ago, and some heater hoses.

The only thing I did not follow the recommendation on the jug was I flushed the coolant every 3 years, not 5 years. The reason was the coolant I bought on sale for $2-3/gal and flushing with T-flush is so easy and very fast too.

 

[RoGuE]

I like the idea of using a garden hose, and then perhaps doing a fill and drain with distilled water.

My Haynes manual shows a picture of just removing the Upper Radiator hose and directing the garden hose into the radiator with it coming out the upper rad hose. I think I might prefer to do that instead of starting to cut into hoses to install the T.

Do I need to get a new gasket for the thermostat when I remove it, or is re-usable? And on that note, should I go ahead and buy a new one since it is coming out anyway? It is the original one with 114k miles.

 

[mechanicx]

Usually the thermostat has a rubber o-ring gasket that is reusable, but if the t-stat is original w/114k miles I would replace it. Many would recommend an OEM thermostat, but a Stant superstat is usually good too.

I have installed several t-flushes and it is really simple to cut the hose with a razor blade, it does not affect the hose strength after the T-flush is installed and they are not leak prone, but I can understand if you want to just take out the t-stat and flush with a garden hose through the top of the radiator. Also you can idle the engine while flushing to help the water circulate through the heater core.

 

[bigmike]

To the OP, I sincerely think the easiest thing to do is just a few drain/refills. I'm changing my FF by doing 3 of them (did one a few weeks ago by pulling the lower hose), over the course of 6 months - 1 year. If the antifreeze looks good and clean, it's a viable option for you.

I avoid tap water completely and flushing the entire system with distilled water takes many flushes to completely remove all traces of antifreeze (or tap water).

 

[lipadj46]

Originally Posted By: bigmike

I avoid tap water completely and flushing the entire system with distilled water takes many flushes to completely remove all traces of antifreeze (or tap water).


It depends where you live and what your tap water is like.

 

[bigmike]

Thanks for pointing that out. That's true. I probably should have noted that. Here, our water is hard water with alot of minerals, typical of the Florida aquifer.

 

[mechanicx]

But if he takes the thermostat out to flush the system with a garden hose, it'll take no time to get the tap water out running the engine while adding distilled water. Ohio has hard water but not the city water around here and it never cause any problems. Most people don't have relatively hard water like in Europe.

 

[lipadj46]

Originally Posted By: bigmike
Thanks for pointing that out. That's true. I probably should have noted that. Here, our water is hard water with alot of minerals, typical of the Florida aquifer.


Yes depends, in NY state the water is generally fine unless you have a well and don't treat the water for minerals

 

[RoGuE]

Ok, so let me make sure I have this procedure down.

1. Drain the radiator using the valve on the bottom of the rad (it even has a nifty hose to use) to get rid of rust and sediment on the bottom. Close the valve.

2. Remove the thermostat. Close back up.

3. Remove coolant surge tank cap. Remove upper radiator hose and insert garden hose. Direct upper radiator hose into a bucket.

4. Start car. Turn on heater. Turn on water. Wait for water to come out clear. Then take out garden hose and use 2-3 gallons of distilled water to flush through.

5. Shut car off. Reconnect the upper radiator hose. Replace thermostat. Add 7.25 qts of Dexcool. Top off with distilled water.

Then done?

Am I supposed to keep the coolant tank cap off the whole time?

 

[mechanicx]

Originally Posted By: RoGuE
Ok, so let me make sure I have this procedure down.

1. Drain the radiator using the valve on the bottom of the rad (it even has a nifty hose to use) to get rid of rust and sediment on the bottom. Close the valve.

2. Remove the thermostat. Close back up.

3. Remove coolant surge tank cap. Remove upper radiator hose and insert garden hose. Direct upper radiator hose into a bucket.

4. Start car. Turn on heater. Turn on water. Wait for water to come out clear. Then take out garden hose and use 2-3 gallons of distilled water to flush through.

5. Shut car off. Reconnect the upper radiator hose. Replace thermostat. Add 7.25 qts of Dexcool. Top off with distilled water.

Then done?

Am I supposed to keep the coolant tank cap off the whole time?



Sounds good to me. Yes leave tank cap off at all times. You alternatively could leave the radiator drain open while flushing with garden hose then shut off engine and close drain and restart engine when you go to add the distilled water. After installing t-stat and pouring in 7.25 qts of concentrate and topping with distilled water you will have to run the engine with the cap off till hot too bleed the system.

 

[RoGuE]

So leaving the rad drain open will let the water come out of there instead of the upper hose? Perhaps I will do that. I will be doing this sometime next week so I think I should be good until I think of another question to ask.

 

[mechanicx]

Well you do want water to come out the upper hose while flushing with a garden hose and running the engine. That way you know that water is being flushed through the engine. It's just the garden hose will probably flow more water than the open radiator drain, so water should still go through the engine. I figured you'd want to flush the radiator out therough the drain while also flushing the engine. I didn't mean to complicate it. you could probably close the radiator drain after a bit.

 

[RoGuE]

Oh, I understand what you mean. You didn't complicate it, lol. I'm a slow learner, but when I get it I get it. This board has been great. I've learned how to change my own oil, flush my transmission, replace diff fluid, spark plugs. Coolant was just last on my list.

I'm just glad my dad doesn't mind me using his Suburban and only means of transportation as a guinea pig.

 

[RoGuE]

I have thought of another question.

I know I need to collect the old coolant and dispose of it properly.

But do I need to collect all of the flush water or the first gallon or so which may still have traces of coolant in it? Or will it all have traces of coolant in it?

 

[RoGuE]

I was looking in the owners manual in the capacity section and it says for my engine:

Vortec 5300 with front A/C: 14.4 quarts
Vortec 5300 with front and rear A/C: 15.8 quarts

and at the bottom it says: Add one liter if equipped with rear heating for all engines.

It has 3 rows of vents, and can get A/C and heat in the rear obviously, so does that mean I go by the 15.8 quarts + 1 Liter spec (making it 16.9 quarts)?

And what difference does having rear heat and A/C have on the coolant level?