Cut corners on radiator drain& flush, consequences?

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My coolant turned brown so that became my first clue that maybe I should drain, flush and refill it. Unfortunately I couldn't find the coolant drain plug, meaning I was only able to drain the radiator from the little hose underneath it (with the butterfly-like faucet, I forget the name...). I did flush the fluid with a garden hose until the water came out relatively clear and stopped dripping. Anyway, when it came time to refill, it would only take in about 4 quarts, out of a total 6 quart capacity -- Hayne's manual said 6.2, and the radiator cap had "6.0" written on it. I used a 50/50 mixture of prestone anti-freeze / coolant. Also, although I bought radiator cleaner (seeing as the brown coolant could be because of rust, or something... I dunno), I didn't use it because it was beginning to get dark and I wanted to complete the job.

So my question is, with all these corners I cut, would I need to just start over again and change the coolant properly? If I don't, are there are problems I could face down the line? What do I do now?

Oh, also, I took all the antifreeze that dripped out to my dealer to dispose of it. But do I also need to get rid of the diluted coolant (from flushing) similarly? I used a bucket to catch the first round of water + coolant I got, the others I just tossed on the grass because I figured they were too diluted to cause any damage, anyway. I still have the first round sitting in a bucket till I figure out if it's safe to just toss. Thanks.

posted by  JaneiR36

Ugh. I should have at *least* run the system with water in it like you said. I'll probably just wind up doing this again before the next round is due. Thanks for your help.

posted by  JaneiR36


Should I just do it over right away? Also, do you know about that second drain plug I was describing (the one I couldn't find) and the importance of draining the system from there too? Finding it is the only part that could be a little aggravating in my do-over -- Haynes manual has an extremely local diagram that is not helpful at all, other than saying it's on "the back-side of the engine block". Also, can you please tell me about how many hours I need to allow the engine cool down before refilling with coolant? Do you usually bother with this step?

posted by  JaneiR36

JaneiR36, how exactly did you flush your system? Where did you put the garden hose and run the water? Did you actually use a Prestone Flush Kit where you splice the T-connector into your upper heater core hose?

As for using the cooling system drain plug at the back of the engine, it may not be needed if you flush the system properly.

To answer your question regarding whether you should re-flush the system, my opinion would be to not worry about it right now. Run the car until next summer and look at your coolant again. If it turned brown on you again then do another reflush and run your engine with the heater on like tbaxleyjr suggested.

To answer your concern about refilling your radiator and the reduced amount of coolant you had to add.... That depends again on how you flushed your system. If you did get a complete flush, there may be some air trapped in the system. Usually the air will work its way out through the coolant reservoir so make sure you keep that filled and monitor it closely for a while. Also, periodically check your radiator to make sure it is filled. (yes, let it cool first)

You do want to make sure you get as much air out of your system as possible though. There are a couple ways to do this. One is to run the system for a couple of minutes with the radiator cap off and look for air bubbles. Make sure the thermostat opens. (you can usually tell this by how quick the coolant is moving in the radiator) As the coolant level drops, add more to it and keep it topped off.

If you did use the Prestone kit, you can also use that T-connector to get some of the air out. You can make that T-connector the highest point in your cooling system by lifting it up as far as you can. You will want the radiator cap on for this procedure. Lift the connector up as far as you can and remove the cap from the connector. Then slowly add fluid to the T-connector until you can't add anymore. By having the connector raised, any air in that part of the system will come out there. This is ususally the largest source of trapped air because a lot of heater cores are higher than the radiator.

If you did not use the Prestone kit, you can do the same thing by removing the upper heater core hose at the end furthest from the heater core and fill the system through that hose. The problem with this is that you need to cap off where you removed the hose from so that the coolant doesn't just leak away. Also, it is a bit more tricky to reconnect the hose once the system is filled. You have to be quick putting the hose on.

Whew, my fingers hurt. Hope this helps.

posted by  theman352001

okay... just lost a reply I attempted to post... even had a tacky joke in there about "you the man".... it was tacky then but it's just plain sad now.

Anyhoo... I didn't use a special kit to flush the radiator, just took off the cap, let it drip and then turned on the garden hose on the opening :oops:

I'll just keep a close watch like you've said and maybe sure the resevoir has a good coolant level in it.

Thanks again for all the help!

posted by  JaneiR36

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