ztim

I am going to drain my radiator. While I'm at it, is there a good way to drain the water that is in the engine block too?
Thanks

Oldsguy

Most of the block should drain as well since the drain petcock on the radiator should be the lowest point of the system. I suppose you could have some pockets in the block or the heater core that might not drain completely. If you want to be sure to get all the old coolant/anti-freeze mixture out you could use one of those coolant system flush kits in the hose that goes to the heater core and run fresh water through per the instructions on the kit. Then when you drain the system the small amounts of water left would be just water, no coolant or rust debris (if it was loose).

ztim

Thanks Oldsguy. I'm going out right now. I started to drain it about an hour ago and now have a hose with a slow stream running into the top.

gerlof_1

best way is to remove the thermostat also,and then flush whith water.
dont forget to put the thermostat back.

ztim

I flushed it out and checked the flow. Everything looked okay. I didn't do it with the heater on. Would the core need flushing as well?

gerlof_1

when youre on the job,do it right i gess.

J-(Chicago)

I would say the core almost definitely needs it, because it is a low point in the system that collects garbage. It is finned on the inside like your radiator is.

88 coupe

What "core" are you referring to?

Coolant, below the water pump, cannot exit the block and must be drained separately. This is done, by removing the pipe plugs at the bottom of the water jackets. There is one on each side.



Back in the days before "permanent antifreeze" they used petcocks, as systems were drained, and refilled, twice each year.

Norm

ozoneblue

sure if you want to dissemble half the engine to get to them . Thank goodness this aint the old days .PS some of the old timers would add 1/2 gallon of SHINE to keep them from freezing .Not sure it all went into the radiator?

Oldsguy

Ztim,
Flushing the heater core would be a good idea too. The flush kits provide a "T" that you insert in the heater hose to the heater core and this allows you to attach a standard garden hose and inject cool water into the sytem there. That way, you can keep the engine running with the heat on high; if your system is working this will keep the heater contol valve open and allow coolant flow through the heater core. When this happens, you can open the drain petcock on the bottom of the radiator, add water through the "T" and run the engine with the heater on, thereby flushing the heater core as well. As Norm noted, there will be some debris and fluid trapped below the water pump and for a thorough flush you might want to open that up when the engine is cool. As he said, you would have to re-plug it or put a petcock in there when finished. I think what you might get is some sediment that would be too heavy to flush out through the system when the coolant is flowing at full speed (whatever that would be).