coolant flush question

titanium10k · May 1, 2006

When the dealer does a flush do they just drain and refill or normally flush when the coolant looks good. Also how well does the purge tank work after a refill of the system, seems like air would still be left over to cause problems.

Nice rig · May 1, 2006

A coolant flush is a pretty simple procedure. For a fraction of the cost you can do it yourself, as for air in the system I don't see why there would be a problem with it.

titanium10k · May 1, 2006

A coolant flush is a pretty simple procedure. For a fraction of the cost you can do it yourself, as for air in the system I don't see why there would be a problem with it.

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I just did it over the weekend it was easy...I drained then refilled with water and drained again. Did this a few times until pretty much clear. I seemed to get all the air out of the system just not used to filling radiator thru surge tank.

mblrds · May 2, 2006

So, after a coolant flush, the way to refill the system is thry the surge tank?

How is it done?

titanium10k · May 2, 2006

So, after a coolant flush, the way to refill the system is thry the surge tank?
How is it done?

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well there is no other way to add coolant to radiator so you use the surge tank. Start it up and add coolant as it draws it down.....cycle engine rpms up and down while adding.

pm26 · May 2, 2006

To avoid trapping the air into the system, idle the engine with the overflow tank cap OFF after refilling the system with coolant. Then add more coolant if the level in the tank drops.

SMarlin40CL · May 2, 2006

Hey Guys, first of all let me say sorry if I'm doing this Internet Posting thing the wrong way but I'm new at it. My question:

I'm recently new at working on trucks but I want to learn to do more to save my self money while gaining experience. I purchased a Chilton's book and have began some simple processes on my truck which recently hit 100,000 miles. I was draining, flushing, and replacing the Dex-Cool coolant when I ran into a problem. I could not find the Cylinder Block drains, because they were pictured different on my truck than the book. The only thing I could find that looked like it would be was an inward hex bolt which I did not have to tool to open.

Where are these 2 Cylinder block drains, and what do they look like?

'99 GMC Sierra

Thanks for your help, feel free to e-mail me with an anwser or post on in here. Once again I'm new at this so I'm sorry if I posted this in the incorrect place

Andrew

sflichel · May 6, 2006

Take the top rad hose off........use a funnel and pour the antifreeze in that way......replace hose and then use overflow tank to top it off.

C & A s Dad · May 7, 2006

Andrew, I know of no reason that you need to drain the block or heads. If you flush the sytem using normal methods you will flush the entire system.

I completed the job on my Yukon XL a few weekends ago and it is very easy. A SUV with rear heat takes a little longer because you have to run the truck long enough to let the flush and the clean water work it's way through the rear heater core.

Air is not an issue with these trucks because the jug is higher than the block. The only time I have seen an issue with air in the system is when the radiator is lower than the engine such as it is on many late model cars.

I am in the Auto Parts industry and we sell many chemicals, some are made to sell and a few are made to use. I added a product called Kool It from Lubegard to my system. This is an excellent product which will not only drop the temp of your system around 5 to 7 degrees but more importantly, it will help tremendously to eliminate electrolysis.

SMarlin40CL · May 8, 2006

Thanks Trey

SO the standard procedure would just be to drain, disconnect the upper hose, remove the thermostat, shove a hose in their and run till its clear?

Thanks man

C & A s Dad · May 9, 2006

I have heard that some people will remove the stat while flushing. However, I do not feel this is necessary unless you are replacing the stat anyway.

The std procedure would be:

Drain the coolant, refiill with water and a good flush. If the system is not too bad, I would use a mild not acidic, not caustic flush. Run the trk for 10 to 15 mins after reaching operating temp. Kill the engine, let it coold for 10 to 15 mins and drain. Refill with clear water, run again for 10 to 15mins and drain again. This is where I took an an extra step or two. Instead of refilling with antifreeze and water, I flushed it with clear water 2 more times. This cost me about an hour but I wanted to be 100% sure I removed all of the flush and old coolant. My truck also has a rear heater core.

I did not notice what year trk you had but if it came with Dexcool (the orange stuff), be sure and use it again. You will find a few who argue this, but I believe in Dexcool and trust the GM engineers on this.