K2XX Coolant Flush Overfill

dwchapmanjr · September 18, 2020

I was at the dealer the other day getting a tire replaced and I noticed I needed a coolant flush as its been 5 years and no previous one.

When I got home I checked the reservoir and it was grossly overfilled. I doubt there's room for 7oz of expansion in it. I know sometimes this happens because it needs to burp out some air so I've driven it a couple of times but it hasn't gone down yet. I've got one of these coming tomorrow to suck the excess out if it hasn't gone down tomorrow but wondering if anyone knows about burping these or how to remove air. There doesn't appear to be a radiator cap which is likely why the reserve tank is pressurized.

https://www.amazon.com/gp/product/B07CP8R9MS

Since these are pressurized reservoirs, it seems that a grossly overfilled can cause damage as there's nowhere for the pressure to go except the weakest link which is likely a hose or fitting.

My question is do these heater cores have a valve or is coolant running to them constantly? It is dead summer and I want to avoid heat on full to see if it clears out if I can.

Also judging by design, it seems like it would naturally burp itself fairly quickly.

Before the flush my needle almost always stayed constant at 210 when warmed up, now it seems to fluctuate between the 197.5 mark and 210 which leads me to think either there's still air in there or the overfill is causing excessive pressure that is altering the temp.

dwchapmanjr · September 18, 2020

I did a bit more driving and research and its a bit interesting/confusing.

The "Front" goes to the radiator. i'm assuming the radiator has a pressure switch in there to shoot excess into the tank.

The "Rear" goes to the water pump which I imagine has a similar high pressure switch for the same.

Where it gets really interesting is the CAP has a pressure switch on it too which seems to relieve pressure from the front chamber into another chamber. Seems like this reservoir is both an extension of the radiator and a reservoir with multiple chambers.

It of course has a bottom hose that T's into the water pump's hose going to the lower part of the radiator. this is presumably where the vacuum sucks back in fluid when it cools.

I believe its been sufficiently driven to burp any air. I even drove around with heat on high even-though I don't believe it has a heater core valve. The heater core tubes seem to go directly into the engine and I can't imagine there is a valve in the block.

dwchapmanjr · September 18, 2020

Got a ciphon tool at Autozone and drained it. No the solo cups aren't the permanent storage for them. Going to properly dispose at local auto parts store. Left it a bit above full as I'm not sure it was completely cold. I'll check it again in the morning. It wasn't on a level surface either but much better.

dwchapmanjr · September 19, 2020

Last post on this but as I was draining I noticed my reservoir tank was a little wobbly. I'm guessing when the battery was replaced it wasn't properly secured. Seemed like it wasn't flush against wall so I retightened it. I imagine over time that wobble could lead to premature cracking. It still has some give but no wobble. I imagine the give it has is just a factor of how little securing it has. It just sits on a clip on the side wall and two bolts in opposite corners.

mookdoc6 · September 21, 2020

On 9/19/2020 at 7:28 AM, dwchapmanjr said:

Last post on this but as I was draining I noticed my reservoir tank was a little wobbly. I'm guessing when the battery was replaced it wasn't properly secured. Seemed like it wasn't flush against wall so I retightened it. I imagine over time that wobble could lead to premature cracking. It still has some give but no wobble. I imagine the give it has is just a factor of how little securing it has. It just sits on a clip on the side wall and two bolts in opposite corners.

I get my done at Stealership because, well? No kiddie pool needed and it's way to cheap not to....but yup, I have to remove the coolant too as it's always overfilled. Over the years I have had techs put in straight Dexcool? and tell me it's better than 50/50 etc. Heck, one day I just know they will pull around front with a FERD and say your truck is ready sir? LOL

Got keep a SUPER TIGHT EYE on these fools in AMERICA nowadays!

Edited September 21, 2020 by mookdoc6

Chev85 · September 30, 2020

A turkey baster works wonders for removing too much coolant at least on some of my past cars, can't say I have tried on our trucks though! And, I wouldn't worry about too much looseness on how it's mounted. That plastic goes through a heck of a range of temperatures and would most likely crack if secured without any play.

dwchapmanjr · September 30, 2020

12 minutes ago, Chev85 said:

A turkey baster works wonders for removing too much coolant at least on some of my past cars, can't say I have tried on our trucks though!

Ha - I was tempted to but I only have one so I wouldn't want to use it on food again so I just purchased an apparatus to do it.

12 minutes ago, Chev85 said:

That plastic goes through a heck of a range of temperatures

Yeah, I imagine it does. That's probably why the mounting brackets for it are so flimsy/loose, two loose legs on the bottom and rests against a lip on the wall.