Changed Antifreeze - Now I have a question?

[Cooker]

Today I finally got around to changing my antifreeze in my 96. I opened the petcock on the radiator, let the overflow drain, and then opened the radiator cap. Then I pulled the lower hose off the waterpump and blew air into the line going to the heater core. I think I got about 5 gallons out.



I put it all back together and filled the radiator and the overflow to the full mark. I only fit about 3. 5 - 4 gallons in and I thought I'd have to drive it to get the rest in becasue I flushed out the heater core.



I drove the truck 5 miles, hopped out and the overflow was still full? Hmmm? So I felt the cap on the radiator and it was cool. Shut 'er down on opened up the cap and the coolant was low.



Question is this, why didn't the radiator pull the coolant from the overflow. Do I need a new radiator cap? Is the system not pressurizing right?



BTW the coolant temp was fine during the entire 5 mile trip. It even had the normal cycling, although maybe not as pronounced.



Sorry to be so long I jst wanted to give all the details.



Thanks for the help,

Ryan

 

[Ramafid]

It could be that the thermostat didn't open. Five miles of driving doesn't warm up my truck enough usually to open the T-stat. I would add coolant to the radiator and then drive around for at least 10 min to make sure the T-stat opens. I could be wrong but I think the radiator has to cool down for the coolant to be sucked from the overflow. Good luck.

 

[Cooker]

It could be the T-Stat didn't open, but the temp gauge did cycle so that made me think the T-Stat did open. I'm gonna go take 'er for a longer trip and see what the coolant level looks like after that.



Thanks,

-Ryan

 

[Shooter]

The cooling system must have negative pressure to suck coolant from the puke tank. heat = (blows)pressure : cool = (sucks)vacuum. ( ask MONICA the particulars )



The thermostat has a deairation valve and will purge air to the radiator with out having to heat the cooling system to 180. Just top off radiator, start engine and let run a few min. Top off radiator tank and puke tank. Go for a drive, come home and park it, in the morning check puke tank level, top off if necessary and go. Just keep close tabs on the puke tank untill you are confident there are no leaks and all air is purged.