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What is the PROPER battery coolant level?

71K views 67 replies 25 participants last post by  dale.lature 
#1 ·
My son got his 2012 back from the dealer today after getting the automatic transmission thermostatic diverter valve replaced due to a transmission fluid leak. While we were in the driveway inspecting the work that was done, I noticed that the antifreeze level in the coolant jug for the battery antifreeze in my son's Volt was filled to near capacity to the point where it nearly touches the top of the jug. I checked the level on my Volt and it is just below the flange that is about the 1/2 way point on the jug. The owners manual states it must be above the low mark on the jug.The only marking I can find on the jug is on the side that faces the right-hand side of the car. There is no low mark, but only a double-ended arrow with a horizontal line against the bottom arrow and the top arrow referencing the half-way flange on the jug. The level on my Volt falls within the range of these arrows. My son's has twice as much in his jug. If his is overfilled, is it harmful to his Volt?
 
#2 ·
This is actually quite timely because I roughly want to know what coolant level others have as well. Just tonight I looked at the level in my 2011 Volt (Very Full) and my 2012 Volt (Reservoir Half Full). So I have a similar comparison to you. What prompted me to look was the fact that I just had the battery fix done on the 2011 and was checking to see if they put the filler cap removal prevention on, and the fluid level differences really caught my eye.

I'll keep a watch on this thread.

Thanks everyone...
Michael
 
#3 ·
mortonmj , what really caught my eye was when looking at my son's Volt the antifreeze level was even - straight across both coolant jugs. When I looked at mine, I did not have the same orange level straight across both jugs. The driver-side jug was full up near the top and of course, the battery coolant jug was half-full. Quite a noticeable difference. At first I thought mine was the problem and low on coolant, possible due to a coolant leak in the battery. But I think the opposite is true and my son's level is actually wrong.
 
#4 ·
We need a WOT or Volt Advisor response to this question. Then we need prompt GM follow up with the dealerships to make sure that everybody's battery coolant is being filled properly.
This could be hugely significant.
 
#5 · (Edited)
We need a WOT or Volt Advisor response to this question. Then we need prompt GM follow up with the dealerships to make sure that everybody's battery coolant is being filled properly.
The correct level for the battery coolant has been revised as part of the "battery enhancement" campaign.
There are now 2 different coolant surge tanks depending on if the enhancement has been completed or not
(either performed at factory or in dealership)

The basic instructions are to ignore ANY markings observed on the tank/s.

The correct level will be when the coolant is visible just at the top of the mid-tank seam. A bit above (i.e. <0.5") is fine
Below is a diagram for reference.

While it's not really "harmful" if this tank is over-filled, there should be a certan amount of air space in the tank to permit proper hot coolant expansion and a "cushioning" accumulation effect.If the coolant is low, there might be a leak in the system.

If you have any concerns regardng your battery (or any other) coolant you can give your Volt Advisor a call.
If your tank is significantly over-filled OR below this level indicated you should visit your dealer for service.

HTH
WopOnTour


 

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#6 ·
Was going to start a new topic on the sensor but here migh be the best place.

Internet articles say.

General Motors is installing a battery-coolant sensor to monitor coolant levels in the battery cooling system.
The coolant sensor will notify the driver.

So how are we alerted ?

And is the sensor a magnet reed float switch

http://www.standexelectronics.com/products/fluid_level_sensors.htm

The one near the bottom of that web page they looks like the already posted pictures.

My car had the battery fix this week but the tank didn't have the tamper-proof bracket so I would like to test the fix.
 
#8 ·
Thank you WopOnTour. Highly valuable response as usual.
 
#10 · (Edited)
GM added the anti-tamper bracket, level sensor and low level alarm in response to the NHTSA fire investigation. Here's my take on these design changes.

GM discovered that a leak of the coolant into a charged battery ultimately, after weeks of leaking to allow fluid crystallization and hence a short circuit, caused the fire. It is inevitable that over the long term, some Volts will have leaks into a charged battery due to things like wear and tear and corrosion. Therefore a small number of fires over the long term seems inevitable ... maybe not nearly as many as a gas fueled car, but nevertheless a finite number, however small. So, an engineering fix is the responsible thing to do if it is practical.

A low coolant level is an indicator of such a leak. And you will find out about the leak long before a fire develops. So there is lots of time to get to a dealer for repairs. This explains the new level sensor and low level alarm.

The anti-tamper bracket is to increase the probability that a trained technician will add the right amount of coolant. An untrained person (such as the car owner) could add too much coolant, delaying the onset of the alarm because the coolant level started out too high.

So, I conclude that the level of coolant in the reservoir is real important for the fix to work properly in some circumstances.

WOPONTOUR wrote below:
"While it's not really "harmful" if this tank is over-filled, there should be a certain amount of air space in the tank to permit proper hot coolant expansion and a "cushioning" accumulation effect. If the coolant is low, there might be a leak in the system."

WOT, this is the first time ever that I find myself disagreeing with one of your postings. It could be harmful. Having an over-filled tank will delay the low level alarm, which in some circumstances (e.g. a very slow, long leak into the battery casing with a delayed alarm) could be result in a fire. I believe that GM engineers must have optimized the level against possible leak sizes and the time it takes for a hazard to develop. Why else would they include the anti-tamper bracket except to ensure that the level is right so the alarm occurs when it should?
 
#11 · (Edited)
WOPONTOUR wrote below:
"While it's not really "harmful" if this tank is over-filled, there should be a certain amount of air space in the tank to permit proper hot coolant expansion and a "cushioning" accumulation effect. If the coolant is low, there might be a leak in the system."

WOT, this is the first time ever that I find myself disagreeing with one of your postings. It could be harmful. Having an over-filled tank will delay the low level alarm, which in some circumstances (e.g. a very slow, long leak into the battery casing with a delayed alarm) could be result in a fire. I believe that GM engineers must have optimized the level against possible leak sizes and the time it takes for a hazard to develop. Why else would they include the anti-tamper bracket except to ensure that the level is right so the alarm occurs when it should?
No, it is the air-space that is important , not the lack of additional coolant. So the level was set to create the fluid pressure headroom, not to decrease coolant volume.

It's not like a small amount of coolant entering the battery box is going to immediately create the conditions capable of causing a fire.
Not at all.

So what really needs to be prevented is repeated long term "topping up" of a leaking system (hence the anti--tamper bracket).

WOT
 
#12 ·
so when the level is LOW do we get an engine check light and a NEW diagnostic CODE ?

The Level sensor is two states ? OK and LOW ?

For all I know with the software Update we could have a NEW front panel dash ICON ?
 
#13 · (Edited)
Yes Cord.
The new "sensor" is similar as you describe (a 2-state device). If the coolant level gets too low in the tank it will trigger a specific Type-A DTC, and immediately bring on the MIL as well as a "SERVICE HIGH VOLTAGE CHARGING SYSTEM " message on the DIC.
Until the fault is dealt with and the DTC is cleared charging operations will be disabled.
HTH
WOT
 
#14 ·
WopOnTour - thanks for the info, excellent description as usual! This really cleared up a lot of ambiguity and vagueness concerning what the level should be. As for the coolant levels I am seeing on our Volts, I am going to leave mine alone since it is right near the 1/2 way point on the jug. On my son's, I think I take some coolant out to make sure there's enough headroom to allow for expansion.
 
#16 · (Edited)
Hmm, after this explanation, I wish there was a little warning tag or label on the bracket, to make the situation more obvious and to avoid "don't worry, I got this" syndrome. Something like, "/!\ Fill to just above seam only - do not top off! If coolant being lost, fix source of loss first!"
 
#17 ·
AySz88 - Excellent Idea! How do you go about getting a self-stick vinyl sticker of this type?
 
#18 ·
I spent yesterday afternoon 'tampering' with the battery coolant level on my son's Volt. Since the level was near the top of the jug, I took out about 7 oz to bring it to about 1/4" above the midpoint. It really isn't that difficult to get to. After removing the 10 plastic push rivets, you can remove the plastic panel covering the top of the radiator. All you need after that is a 10 MM wrench. You don't have to remove the bolt, just loosen it enough so you can lift the end of the bracket off of the cap. Once the bracket is off of the cap, you can simply remove the cap. I feel much better now that there is more headroom over the level of the battery coolant now.
 
#20 ·
Mine is filled to the level marked on the tank. I am also assuming that the levels marked on the tank are correct.
 
#22 ·
GM seems most concerned with the Battery Coolant level, even to the point of putting a bracket in to prevent opening it. They did not do that for the other coolant tanks - yet.
 
#24 · (Edited)
I agree with you. Most techs have been filling coolant bottles based on the external markings for so long it has become habitual. The fact the coolant was to be filled to the "revised" level to the seam on the bottle may catch a few of them. But it is correctly outlined within the campaign procedure documentation as well as in the electronic service manual information for "Draining and Filling HV Battery Coolant". (which is where these particular drawings were sourced)

The reality is, the way the special Vac-N-Fill tool works the reservoir is actually first over-filled then drawn down with the tool's vaccum spigot to the correct level.

Apparently the need to use this specific tank meant that it's supplier provided level marks were no longer correct- coming with the engineering desire to have less coolant than the original tank BUT just a bit more total coolant in the system than it's external markings indicate.
But I'll also agree a label to indicate the revision to recommended level might have been an appropriate solution .

WOT
 
#25 ·
Should I ask for a new reservoir?

I bought my 2012 in January. According to this description mint has the first generation reservoir without sensor and no bracket on the lid. So I guess it is fair to assume that my Volt has not been upgraded. Interestingly I was never contacted regarding this upgrade. Should I contact my Volta advisor?
 
#26 ·
I bought my 2012 in January. According to this description mint has the first generation reservoir without sensor and no bracket on the lid. So I guess it is fair to assume that my Volt has not been upgraded. Interestingly I was never contacted regarding this upgrade. Should I contact my Volta advisor?
Yes... Or call your local dealer to schedule an appointment.
 
#30 ·
So after 25 posts on this subject... My question is still not answered:

What is the correct level for the OTHER two coolant tanks?
As per the owners manual the other 2 coolant levels are to be checked COLD and their levels anywhere between the MIN and MAX cold fill lines marked directly on the tanks.
HTH
WOT
 
#28 ·
My experience with repair technicians, which is quite extensive in the IT domain, is that you just can't get them to always recheck the doc before touching a system. It's not in their nature and it would add too much time to the average repair.

Therefore, if it's important to fill the battery coolant tank to just above the seam and ignore the fill mark, it's important to put a permanent sticker to that effect on the tank. Perhaps someone in GM could pass the suggestion to engineering.
 
#32 ·
Meanwhile, I'm trying the writing-on-white-duct-tape method - will check how it holds up. It looks like the person who installed the tank made a little mark on the tank as well.
 
#33 ·
So after my battery enhancement, my coolant was filled to the brim by the dealer. I hate to go have it drained, and be perceived as a real picky owner who has nothing better to do. Is there any way to do it myself despite the anti-tamper design? I would just siphon enough coolant out of there until it's at the appropriate level.
 
#35 · (Edited)
ClarksonCote, I had a similar problem with the coolant in my son's Volt, there was no headroom for expansion. I pulled out all the push rivets, I think there were 10 or so. Along the radiator support was a rubber flap. I pushed it out of the way to see the bolt that held the anti-tamper bracket. If I remember correctly, it was also a mounting bolt for the coolant jug. I did not remove the bolt, but simply used a ratcheting box-end wrench to loosen the bolt about 1/4 - 3/8 of an inch. this was enough to lift up the end of the anti-tamper bracket and allow it to disengage from the cap. While holding the bracket up, I simply unscrewed the cap with the other hand. Where I got into trouble was using my wife's turkey baster to suction out the extra coolant and bring it down to about 1/4 inch above the bottle seam. Rather than let this go to waste, I put it into my Volt via the same procedure and my Volt was brought up to about 1/4 inch above the seam. I have monitored it over the last 5 months and the level had not moved at all. Leaving me to believe there was no consistency in the level being set to a certain point even at the factory.
 
#36 ·
While my son came back home from college this weekend, I told him to check the coolant levels under the hood. When we first got our Volts, my son's Volt coolant was right at the top of the jug while mine was just a little below the seam at the midpoint. Back in April, I used a turkey baster to transfer coolant between both Volts and got the battery coolant level in both of them to the same level. With my son home we checked levels. My Volt has the coolant sitting at almost the exact same level as six months ago, even after about 6000 miles. My son's volt however, had the battery coolant level drop about 3/8 - 1/2" in the battery coolant tank. He has only put about 3000 miles in the same six months that my Volt has gone through. I know there is a sensor to generate a code when the level drops, but what is an acceptable rate of drop-age for the coolant? I told my son keep an eye on the level and to make an appointment at the dealer to have it checked out the next time he is back in town.
 
#37 ·
Confused

Explained to my dealer what this thread states about the battery coolant level after a service. They totally disagree and today received this letter from gm. Can anyone help explain?

CCCVolt@cc.gm.ca

Good afternoon Mr. P,

Thank you for your patience while I made some inquiries with our technical team as well as the engineers for your 2012 Chevrolet Volt.

The high voltage battery surge tank coolant level must be filled to the top of the label on the side of the surge tank.
(this label is at the very top of the tank and leaves the tank completely full with little to no air space)
Your surge tank is equipped with an anti-tamper bracket and a coolant level sensor.

The vehicle must be on a level surface when the coolant level is being checked and checked when cold.

The high voltage battery coolant reservoir is located on the passenger side of the engine compartment.

Please also keep in mind that the high voltage battery coolant should only be service by a qualified technician.

We trust this offers the clarification you were seeking. Thank you for contacting GMCL. Should you require future assistance, please contact us again through our website at www.gm.ca or call our Customer Care Centre, toll-free, 1-800-263-3777 or 1-800-263-7854 (French), Monday to Friday, 8:00am to 11:000Saturdays, 8:00am to 5:00pm, Eastern Standard Time.

Sincerely,

BA
Customer Care Centre Manager


Thanks for any help, this letter makes no sense to me after reading this thread.
 
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