[laurasheaclark]

Modern coolant systems run up and down hill, and have all sorts of drain trap-like bends. Normally they pull a vacuum on the system when they fill it. There should be no need for topping up, if they did that. Prof. Weber shows how it is done at 27 minutes in.

yes, I know about the vacuum. I’m not sure how it got screwed up, but it seems like they must not have done that.

 

[drdiesel1]

I wouldn't think they'd need to if they did the job properly. Unless the battery replacement procedure that they follow specifically says "flush and test drive to verify proper operation".

These coolant loops are controlled by the control modules. Short road tests probably won't even activate the pump. They could probably use the scan tool and use bidirectional control to activate the pump and recheck it.

They don't because the warranty times will not pay them to do so.

Thank Ford for this little time omission. GM took the page right from Ford's playbook to save
a billion dollars in warranty repairs. Good luck getting it done correctly in a flat rate shop!

 

[Jordan Shackelford]

I recently had one of my 2017 Bolt's battery modules replaced, and when I drove away from the dealer I got a service engine light that turned out to be low coolant. They filled it Thursday, and it showed low again today, Saturday. They filled it again today. I was told that they have to flush and refill the coolant when they replace a battery module, but shouldn't they test drive it or something to verify it's really full??

Do you remember exactly what the service engine message said?

 

[MisterJJ]

My battery coolant is close to low. Car is 6 months old and this picture is taken at 99 F, so it's not cold weather "shrinkage".

The cap wasn't fully tight. It took about 1/3 turn to fully tighten.

 

[MichBolt]

My battery coolant is close to low. Car is 6 months old and this picture is taken at 99 F, so it's not cold weather "shrinkage".

View attachment 35413

The cap wasn't fully tight. It took about 1/3 turn to fully tighten.

Isn't that the "fill to" line?

 

[MisterJJ]

Isn't that the "fill to" line?

I read that as "If the coolant level is at this line, check the manual" (because the coolant is low at that point).

So checking manual, it says:
Checking Coolant
The coolant needs to be replaced at the appropriate interval. See Maintenance Schedule 0 301

Maintenance Schedule says:
Fluids Proper fluid levels and approved fluids protect the vehicle’s systems and components. See Recommended Fluids and Lubricants 0 307 for GM approved fluids.

Recommended Fluids and Lubricants section says:
Vehicle Coolant Circuits - Use Only Premix DEX-COOL Coolant (GM Part No. 12378390, in Canada 10953456). See Cooling System 0 238.

Cooling System says:
Nothing. It's back to where I started with "Checking Coolant".

Stupid manual.

 

[GJETSON]

Stupid manual.

Agree. The manual is no help. That is the fill line, however. Your coolant level is fine. If you are thinking it is getting pretty close to that hose connection, coolant only comes into the reservoir through that hose. It is an overflow line from the two onboard battery chargers.

 

[MisterJJ]

Agree. The manual is no help. That is the fill line, however.

Really? So there's no "low" line? The other two tanks are a quite a bit higher so this one stood out. My other/previous cars have a seam or molded part of the tank for the fill line but a very distinct "Min." line that was clearly marked. Seems like that would be the important thing to have an indication line.

 

[GJETSON]

Really? So there's no "low" line? The other two tanks are a quite a bit higher so this one stood out. My other/previous cars have a seam or molded part of the tank for the fill line but a very distinct "Min." line that was clearly marked. Seems like that would be the important thing to have an indication line.

Our earlier cars had a fill line, and a low line. Or maybe it was a hot, and a cold line.

All three of our reservoirs were between 1/4" and 1/2" above the line when we got it four years ago. They go up and down slightly due to thermal expansion, but never go below the line.

I guess they figured there was so little thermal expansion in an EV that one line was enough. But we know you can never have too much information.

 

[PLP]

I am not sure the best place to ask... bu why not.
Since the traction battery replacement, each time the battery heater kicks in (either after the Level 2 charge or in DC) I can hear some very loud and distinct gurgling. Kind of like there was some air trapped.... OR.... like the heating element was heating the coolant too quickly without enough circulation and the coolant evaporates locally (I hope the latter makes sense)

The tank is full.


Do you hear that as well?

 

[GJETSON]

The tank is full.


Do you hear that as well?

Don't worry about it. There could be some air in there yet. If so, it will eventually work its way out. The coolant, and the cooling channels are nowhere near the cells anyway. What heat transfer there is, comes from the solid aluminum plates between the cells.

 

[PLP]

Don't worry about it. There could be some air in there yet. If so, it will eventually work its way out. The coolant, and the cooling channels are nowhere near the cells anyway. What heat transfer there is, comes from the solid aluminum plates between the cells.

that's what I thought, but it has been like that since January last year...

 

[GJETSON]

that's what I thought, but it has been like that since January last year...

Then what you are hearing is normal. There is no way an air bubble is going to survive in that simple coolant loop for that length of time. There is a total of 7.0L, or 7.4 quarts, in the system, and the loop is much less tortured than the coolant passages in the typical ICE engine cooling system.

 

[PLP]

So do you hear it as well then?


Besides, acording to the video, the only way to refill the system is to use vacuum assisted refill.

 

[GJETSON]

So do you hear it as well then?


Besides, acording to the video, the only way to refill the system is to use vacuum assisted refill.

Yes. On the rare occasion when it runs.

Refilling is not required if there is air in the loop. Running the battery coolant pump, and probably the battery heater too, will eventually drive all air to the top of the reservoir. Just keep an eye on the coolant level, so it stays at, or above, the line.