Drain Coolant...expansion tank

[coopns]

I pulled the plug on the rad for Caravan 02...let'er drain, tightened it back up and mix 50/50 with some Havoline/Dis. water. I try to do it once a year. Think that is ok? The Havoline says 5 year.

1. Why does the expansion? tank not rise/fall with the draining of coolant?
2. Why after the drain and fill did it take about 2 mins of the car running to get heat, even though the heat gauge was up to half? I thought I messed something up but it just blew cold air and then the heat came after about 2 mins.

 

[mechanicx]

For 1., the tank is probably lower than the radiator overflow and you would need suction for it to siphon. For 2., there was air trapped in the system so it had to bleed out before the heater will heat up. This is normal.

 

[tomcat27]

I cant speak for the Caravan - but on many cars you can drain the overflow by leaving the radiator cap on, removing the overflow cap, and opening the drain. once the tank is empty you can open the radiator cap.

as far as the delay for heat, the heater hoses and heater core probably were drained and were full of air. the air wont self-bleed until the thermostat opens - which takes a few mins.

 

[Eddie]

Agree. All vehicles I've owned required me to leave the radiator cap ON in order for the over-flow take to empty.

 

[mechtech2]

'Puke' tanks need to be cleaned and the fluid changed along with the radiator flush. It is a separate process.
In real life, unless they are actually dirty, there is no problem. And the small amount of coolant is not a big deal, either.
The reason you had no heat is air pockets. This is normal and usually fixes itself. Keep an eye on the reservoir level.

 

[coopns]

The wife drives it...so she had it out today for a 45min cruise. She came back and it leaked coolant, not much. So I just got home and it did leak some, I was expecting a bone head move by me...like not tightening the drain plug enough but the leak was right around the cap. I thought I tightened it up but possibly not.

Could there have been that much pressure where it would have seeped out of there or did I just not snug it really tight?

 

[coopns]

And...I saw a NAPA rad cap with 16 lbs...should I put a new one one? Is that sufficient 16 lbs?

 

[mechtech2]

A new cap is a good move, right now.
And make sure the area is CLEAN from debris.
16 enough? Go with the factory type - as close as you can get. 16 may be too much.

No so much for cooling, but for puke tank operation.

If the leak is a cracked neck area, JB quick weld can fix it. Roughen up the area nd clean it, then apply the mixture.