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Coolant change

I’m about to change the engine coolant on my

'98 Grand Caravan. I remember the first time that I couldn’t get a full flush (like I had on other older cars I had done this on.) Can

someone give me some advice?

There are a couple of ways…One is to drain the block if there’s a drain plug for the block.

What I’ve done…is to drain the radiator…refill with water…run the car until up to normal operating temp…then drain and repeat. Does a great job at draining the fluid.

If it is really difficult to remove all the water, I do it like Mike suggested. I dilute it until there is nearly pure water in the system, then drain out what I can and add pure antifreeze to get the desired 50:50 mix.

Don’t fill with cold water. If you’ve drained hot water, fill with hot water.

Thanks to those of you who replied. I’ll put your ideas to work as I tackle the job.

If you have hard water, do a drain, fill, circulate and drain with purified water before your final fill. Maybe repeat multiple times if you have really bad water.

what’s wrong with a coolant flush? alot of the machines out there use a 3 step process that you can’t mess up. first you put your additive into the system to break down the deposits. flush your system with new mixed 50-50 coolant and drain the resevoir when done flushing. reconnect the system and install a coolant sealer that relubricates the water pump and fill up the resevoir. the whole process is done in 25 minuites tops and not only is your system a 50-50 mix but all of the coolant is taken care of for you. I’ve done coolant flushes both ways and i would take the machine anyday. just my two cents and hope this helps.

My experience with a 99 Voyager is that the radiator drain plug is tricky. Now that I put in a new o-ring first time I struggled with it, I leave it in. Put the front of the van up on ramps. Take the lower rad hose off the engine and drain into a big plastic box, with the rad cap off. Remove the overflow bottle (one screw, and a hose clamp to move) and clean it.

I refill with water, run the engine a few minutes, then shut it off and let it cool for an hour or more. Then drain, put in half the system’s capacity of straight coolant (about 5 quarts of coolant), and top up with water. Let the engine run, adding at the rad cap. Collect spillover as it heats up.After it seems full, put a 50-50 mix in the overflow bottle. Next couple of times you have a cold engine, top up the rad and the overflow with 50-50.

Always collect all coolant solutions, put them into firmly capped containers, and handle as hazardous waste. The solution is attractive to animals, and it is a bad poison that can destroy the kidneys. Be safe, not sorry!

We have a chain organization here in Tucson that is using “reclaimed” coolant. This caught my attention.

I also don’t like messing with the radiator drain petcock,they seem to be fragile.

The only blanket statement that can be made for coolant disposal is that it should be disposed of according to local regulations. In some areas the municipal authorities tell citizens to pour it into the drain. That is not the surface water drainage, but the sanitary sewer (ie. down the toilet). Apparently it does degrade in the sewage treatment process.

I believe that the major contaminant in spent coolant is oxidized glycol products. They would be negatively charged and easily removed by an ion-exchange process.

alot of the machines out there use a 3 step process that you can’t mess up. first you put your additive into the system to break down the deposits.

You own one of those machines?? I sure don’t…and many people here I’m sure don’t.