flushing the cooling system

[HeWhoKillz]

What tools do people use to flush the cooling system? I'm doing this on a 94 caravan but I doubt that will matter.

[vgames33]

Shops use a machine that forces pressurized coolant in and collects the old as its pushed out.

If this is just a maintenance thing, pull the lower radiator hose and drain out what you can before refilling. I use compressed air through the radiator cap to get a little extra out.

If you have a blocked cooling system, there are many flush chemicals out there but you'll have to do a more complete drain.

[Blt2Lst]

Originally Posted by HeWhoKillz

What tools do people use to flush the cooling system?

A garden hose.

[HeWhoKillz]

Well, I have barely any heat in this van. There is "more" heat when its driving or revving. At a stop, it gets much cooler. Both of the hoses going into the firewall are hot. Flushing it didn't help. So I'm not for certain it is a heater core.

[vgames33]

Could be the water pump or low coolant/air pockets.

Did you flush the core itself? Since you can access the lines to it, shove the garden hose in there and pump water through it.

[HeWhoKillz]

Originally Posted by vgames33

Could be the water pump or low coolant/air pockets.

Did you flush the core itself? Since you can access the lines to it, shove the garden hose in there and pump water through it.

Wouldn't the car overheat? I'm not experiencing that.

[vgames33]

You should see overheating with a worn pump or low coolant level, but if the pump is marginal (fins rusted away, but not completely gone), you may get weak heat at idle without noticeable overheating. The water pump is the last part I'd check due to the work involved. Pump failure is common on the 3.3/3.8 engines.

Try flushing the core directly and see what happens. You should be able to tell if its clogged by watching how easily water flows through it.

[Toolaa]

Originally Posted by HeWhoKillz

Well, I have barely any heat in this van. There is "more" heat when its driving or revving. At a stop, it gets much cooler. Both of the hoses going into the firewall are hot. Flushing it didn't help. So I'm not for certain it is a heater core.

This sounds like an air bubble trapped in the system. I'm not 100% sure but many minivans have the heater core above the highest point of the engine. So any air in the system will eventually find it's way to the heighest point. When the engine is running at idle there is not enough water pressure to flow past the bubble. However when the engine is running faster the pump pressure is able to overcome some of the bubble and some hot water does circulate through the core.

There is a tool you can buy called the Airlift 550000. Or search for other models of "Coolant Vaccum Refill" tool. There are videos of how to use them on you tube too.