2001 Suburban Water Pump Replacement?

[311Hemi]

My water pump has had a slow leak for a long time and I need to replace it now. The new one just showed up at my door, along with a new thermostat, and two new belts.

My questions:

1)My coolant ran low about a month ago, and I added some of the green stuff to the coolant reservoir. It was probably 1/4 of the coolant overflow tank worth of the green stuff. The system has Dex cool. Will this be an issue?

2)Should I just drain the system when replacing the water pump, and fill it back up with new Dex cool again? Or is there a better way of doing this without bringing it into a shop for a full flush?

I was originally thinking about emptying what I could from the system from the coolant lines that I will be disconnecting, filling it with distilled water and driving it for 10-15 min to get the water running through the system, and then draining that and adding the green stuff.

Any thoughts on the best way to proceed?

[Scott K]

Dex cool, while it sounds really good, it isnt. Personally I would drain and flush it, and put green back into it. But if you think the green didnt get mixed with the Dex cool, just empty the over flow, and just refill the system back up with Dex cool. Basically, Dexcool is a long life, but if it gets mixed with green, you are to treat it as if it is green. But Dex cool has cause many issues in cooling systems over the years.

[Macgyver55]

Not a good idea to mix them at all. It can create a strange substance with no name. Its always best, and usually required for a water pump warranty to flush the system.

Dexcool has gotten somewhat of a bad rap due to people thinking it was good forever and left it in far longer than it should have been. I havent experienced many problems with it as much as some others, but then we did flush and fills on our company vehicles at earlier intervals than called for.

[Jeremy airjer W]

180k on the Saturn, still has dexcool in it.

The systems that use a pressurized reservoir seem to have less issues with dexcool than the vehicles that use a non pressurized overflow type reservoir.

[311Hemi]

Jer, any ideas if you think I need to have the whole system professionally flushed because of the small amount of green I added to it?

Any thoughts on the draining and filling with distilled water to try to flush things a bit, and then adding new?

[Jeremy airjer W]

For $90 (approximate cost of a coolant flush). Is it really worth draining, filling, running, draining, filling, and then disposing of the coolant?

The small amount of green in the system is probably not going to hurt. That and you will be diluting it when you pull the pump and the anti-freeze drains from the engine.

Like somebody above mentioned water pumps and radiators will usually have in the fine print, must flush for warranty. I don't know how strongly this is enforced.

[Macgyver55]

I don't know how strongly this is enforced.

I really don't either, and I've replaced plenty of pumps with a simple drain and fill not knowing what was in there to start with and had no comeback problems. Pulling the pump off is going to drain a large percentage of the system capacity for the most part so as long as you dont reuse what you drain there shouldn't be a problem.