disconnect bottom hose instead of drain plug?

[CBDFrontier06]

Instead of disconnecting / reconnecting several times to flush, just remove your bottom hose once, let the radiator and block drain, and re-connect. Ready your garden hose. Disconnect the top hose and crank the engine. When the thermostat opens, the old stuff will start pouring out the top hose. Turn on the garden hose and stick it in the top of the radiator and let the system flush itself for a while. When the water runs clear out the top hose, turn off the garden hose and let the pump drain the radiator. Start pouring your 50/50 mix into the radiator until you start to see green coming out the top hose. Reconnect the top hose to the radiator, top off the radiator, cap it and fill the reservior. Take it for a drive, allowing the system to draw from the reservior and check the level when you return home.

 

[George7941]

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When the thermostat opens, the old stuff will start pouring out the top hose. Turn on the garden hose and stick it in the top of the radiator and let the system flush itself for a while

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There is a huge risk of a cracked block if you let cool water into a hot block. DO NOT DO IT!

 

[abimanyu]

Hi, I'm gonna clean out my coolant and radiator tomorrow but too much hassle reaching for the drain plug. so is this gonna be ok? Siphone coolant from the overflow tank,disconnect bottom hose. I want to disconnect all hoses, clean the hoses too,clean the connecting holes and add permatex hi temp sealant.Let all the coolant drain, reconnect hoses, fill with prestone flush and distilled water,run engine. Drain through the bottom radiator hose, connect hose, do it all over again four time.

So my point is, I'm going to use the bottom radiator drain hole instead of the drain plug. Easier for me to get to the bottom radiator hole than the radiator drain plug. Will this be ok?

 

[m2200b]

Ok I usually use that hose too. WHy would you use rtv sealant on hoses. I'd just use it on tstat.

 

[CBDFrontier06]

What do you think the block is getting when the thermostat first opens? The water in the radiator is still cold at that point.

 

[abimanyu]

I'm done with it. Actually I took all the hoses off,drained the coolants and opened the drain plug. cleaned the hoese thoroughly,flushed them out,clean the mounting holes,I saw some black debris on the mount of one of the hose. My mistake,didn't apply rtv but Permatex High Tack High Temprature gasket sealant,dark purple gooey stuff!

Cleaned the mounting points on the radiator and engine block with denatured alcohol. Refitted the hoses.

I poured a liter of distilled water through the radiator cap and let some old coolant out. Closed the drain plug. Pour a bottle of Prestone Super Plus, what the heck, might as well do it. Top off with distilled water, run the engine for 15 minutes with ac on. Shut down engine, had lunch,came back and drained the old coolant and flush.

Refill with distilled water,15 minutes,off. Repeat one more time. There was still a little bit of old coolant everytime I drained with distilled water. I don't know how many flushes that I have to make to finally get all of them out. It was getting dark so I drained 3 times. I think one more time would be good.

Then finally add Prestone Coolant Additive then top off with pre mixed Prestone coolant.

Ran the car, seemed fine.

 

[George7941]

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What do you think the block is getting when the thermostat first opens? The water in the radiator is still cold at that point.

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Good point, CBDF! However I still think there is a risk of the block cracking. Themostats open very slowly, the initial flow of coolant past the stat is just a trickle and hence the flow of cold coolant into the block is also just a trickle. It takes a few minutes of the engine running to open up the stat completely( the cool coolant coming in lowers the temperature of the coolant in the block ). The dilution of the hot coolant in the block with cool coolant from the rad takes place over many minutes and hence the thermal shock is greatly reduced. One other problem I see with your procedure is that as soon as the cool water gets to the stat the stat is going to close up and the flushing procedure is going to be limited to maybe ten to twenty seconds.

 

[CBDFrontier06]

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Originally posted by George7941:
One other problem I see with your procedure is that as soon as the cool water gets to the stat the stat is going to close up and the flushing procedure is going to be limited to maybe ten to twenty seconds. [/QB]

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That wasn't the case with the 99 Dodge Ram I flushed last year. I drained the radiator and block, reattached the bottom hose and took the top hose off the radiator. Filled the radiator with the garden hose and cranked the engine. As it warmed up the thermostat slowly opened. It started with a trickle and after a few minutes, became a torrent of steaming water out the top hose. As this took place, I increased flow from the hose..and it eventually reached the point where it was barely able to keep the radiator full. This continued until I saw water run clear and I shut off the engine. The thermostat never closed back up during the flush. It might have if the garden hose water had been 33 degrees, but it remained open until I shut it down. Performed the same process on a 94 Eclipse, 78 Monza, 86 Civic, 91 Civic, 93 Altima, 99 Explorer, and 93 Sundance. Never an issue.

 

[abimanyu]

It's been almost a month. Just wanted to up date you guys. The cooling system ran fine. I guess the way I did it was good enough! Myth busted of not using Prestone Green Universal in Toyotas.

 

[Ken2]

"Start pouring your 50/50 mix into the radiator"

But you won't end up with a 50/50 mix in the engine. A lot of water remains in the engine after draining. After the flush, is it better to put straight antifreeze into the system equal to half the total system quantity (from your owner's manual), then top off with distilled water.

Be sure your heater is on HI during the flush.


Ken

 

[labman]

After the first try, in the 10 years I had my 92 Grand Am, I never bothered the radiator drain again. I just used the lower hose. Maybe I am not as diligent about changing coolant as I should be. Maybe I paid the price with a blown head gasket at 180K and 10 years.

So I will see how my 02 cavalier does. It is now approaching the recommended 5 year change. Likely I will flush good and replace the Dex Cool with Prestone Low Tox. It seems to have right and left hoses rather than upper and lower. Never have been able to get near the system capacity back in a radiator. I will be adding straight antifreeze and then any water needed to fill it.