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Replacing coolant.

24K views 35 replies 15 participants last post by  WopOnTour 
#1 ·
Hi.

New from the UK, I have ordered a used Ampera on a bit of an impulse buy!! :)

As a matter of routine I like to change all my fluids regularly. I often do it after the vehicle's been serviced too (never really know if they do it properly!!)

I've seen the posting on replacing the transmission fluid. That's great. Thanks guys. (Could anyone pin up here what the plug torque settings are on that job too?? Thanks!)

So there are 3 [water based] coolant systems. In the UK, the handbook says to use 'a recommended antifreeze' and tap water. :( That's what it says! :eek:

Don't like that idea. Like the idea of using de-ionised mix. So, especially on the basis that service bots may well have done just that - thrown in tap water - can anyone say if there are instructions for replacing the battery/electronics/engine coolant?

I'm sort of surprised this hasn't come up before, and maybe it has but I couldn't find a thread. All help welcomed, thanks.
 
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#2 ·
I can only surmise that Europe has deionized water running in the tap...

Seriously, it must be some EU law that prevents GM from specifying a deionized mix. No way is tap water a good thing for the battery cooling based on all I have read. Here, the manual warns against using anything but deionized water for the mix, not even distilled water!
 
#3 ·
Heh. Funny. If only it was, I'd not have to descale my sinks, kettle and washing machines!

It's no problem for me, I can access either filtered demineralised, or fully distilled, water at work to mix if the local dealer doesn't stock pre-mixed. It's just that I've just got some reservations whether hard tap water might have already been added, so would like to flush them out really.
 
#4 ·
That sounds a bit off. My UK Volt manual says:
Coolant and Antifreeze

Use a 50/50 mixture of DEX-COOL
antifreeze and de-ionised water.
The system is factory filled with
coolant designed for excellent
corrosion protection and frost
protection down to approx. -28 °C.
This concentration should be
maintained all year round. The use
of additional coolant additives
intended to give additional corrosion
protection or seal against minor
leaks can cause function problems.
Liability for consequences resulting
from the use of additional coolant
additives will be rejected.
Perhaps the Ampera manual lost something in translation.
 
#5 ·
If you look at the maintenance schedule, these are very long life fluids in essentially sealed systems.
I would personally not be touching them unless absolutely necessary, you can be opening the door to many problems vs the miniscule chance you actually need a fluid change.
 
#9 · (Edited)
I have used tap water for many years (my Buick Regal is twenty years old) , and I had no problems with its cooling system, except for a blown top hose (a defect in the hose, not the coolant). I use Prestone coolant (not the pre-mixed) because I increase the coolant ratio to 60% and add plain tap water for the other 40%. I change the coolant once a year, since we have high ambient temperatures (up to 96 degrees) and I have to travel in a city with plenty of traffic jams. The Regal's thermostat has been changed to open at a lesser coolant temperature to circulate sooner. The Equinox's engine coolant has been changed only once in six years by the dealer.

I believe that the quality of the coolant is more important than the quality of water, and probably that the tap water in Puerto Rico has less contaminants.
 
#12 ·
I have used tap water for many years (my Buick Regal is twenty years old) , and I had no problems with its cooling system,
Hmmmm, Thats weird, I wonder why...

I change the coolant once a year,
Ah! Thats why. Your coolant isnt in long enough to develop scale. Dont be confused though, Tap water is Chuck Full of stuff metals used in engines dont like.
 
#10 · (Edited)
I live in a hard water area and everyone's coolant tanks here build up a scum ring in the expansion bottles after several years.

Clearly, there are very reasonable demands when cooling a 400V battery with water based fluids for it to be a standard of coolant above that needed for an ICE.

I don't 'believe' in any 'long life' fluids. A 'long life fluid' is a declaration of faith, not of engineering definition. If there were some 15 years old Volts around with the original fluids in, I might be placated - but I'd still want to replace my own coolant!

What does 'long life' mean - life of the warranty?.. and then what? What damage might it have left behind without being changed biannually?

Could anyone with a workshop manual info divulge if this is a possible thing to do, or just too specialist to consider?
 
#11 ·
Could anyone with a workshop manual info divulge if this is a possible thing to do, or just too specialist to consider?
Special tools are required (GE-26568 Coolant and Battery Tester, GE-47716 Vac-N-Fill Coolant Refill Tool, GE-46143 Cooling System Adapter). This is not like changing engine oil. I would not call it a do-it-yourself job.
 
#13 · (Edited)
Replacing the coolants on the Voltec system requires a special coolant AND some special tools. A vacuum based coolant removal - installation station (aka Vac-n-Fill) AND access to GDS2 software to initiate flush and air-purging process that utilizes the car's electric pumps and flow control valves within the various coolant loops.
Non-dealer service of these cooling systems is NOT recommended.
WOT

PS> If you do not have access to the specialized "deionized" Dexcool premixed coolant, you would be better off to leave the coolants "as is" otherwise you might start triggering loss-of-isolation DTCs. This coolant is specialized for GM hybrids and EVs where the coolant will be coming in almost direct contact with high voltage. DO NOT USE DISTILLED WATER OR TAP WATER
 
#14 ·
Hmm.. well I hear your comments regarding specialised tools. Looks like a quick drain and refill is not poss. Thanks.

However.... premix dexcool is not available in UK, based on a phone around today. Can't get it. Some of the parts departments thought I was mad... "no 'mixed'. No idea what you're talking about. you mix your antifreeze with water.". Yeah, and tap water at that. Doh!

Makes me worried what I am getting here. What's been added to this car in the past?

OK, so if a full refill is not possible, what I can do is to drain the expansion tank and replace that volume. Looks like it's just under a litre or so. I can do that once a month on a rolling basis, and trust that it either gets slowly rotated or at least the laws of diffusion do their stuff and I cream off a little 'old' stuff each go.

I will have to mix what's available with de-ionized water.

What I don't like the look of is like in the thread;
http://gm-volt.com/forum/showthread.php?145578-Proper-Coolant-level-for-the-propulsion-battery
where the battery coolant has clearly de-colored over time.
 
#18 ·
#24 ·
YES! The deionized water designed for dry cell battery fills or non-maintenance type "top-ups" will do nicely!
There is a drain on the battery so the coolant can be removed, that's no the issue. The issue is filling the system and getting all the air out of the battery, this is the reason for the special tools.
Actually no, there is no drain on the battery. The drain procedure requires specific cooling lines to be removed in a sequence. It will require a hoist.
WOT
 
#19 · (Edited)
Coolant change is something we should be talking about. 5 years or 150k miles is recommend so 2011 owners are coming up on this for time. Not sure if any one here has had the coolant replaced for the batteries, what would the cost be? I work at the dealership and will be recommending this soon for the 2011's but have not come up with a labor time. It's true that this is not a drain and fill type system, special tools and some knowledge is required. No cleaner is used, draining the batteries and performing the fill process with the MDI and GDS2 will be required. The system only uses about 6 quarts of coolant so 2 gallons would be more then enough to performed the service. There is also a in-line filter for this system located at the battery inlet hose, not sure if it's a good idea to replace this filter unless there is a flow issue. Draining and filling the battery as a service should be about 2 labor hours and should only be done by a Volt tech and not a lube guy so if you have this done make sure that only a volt tech will perform this service. Filling the system and getting all the air out of the battery, this is the reason for the special tools.
 
#20 ·
The system only uses about 6 quarts of coolant ....
That's super-useful information, thanks, because that gives me confidence that an 'occasional' reservoir replacement (maybe every 3rd month, if it is only 6 quarts worth) will cycle through the coolant and replace it over a period of a couple of years.

Do you have the volume of the electronics circuits? Is it similar?

It looks like the electronics and battery reservoirs share a top-level. Is that right? You'd only need top one up and it will flood over into the other reservoir (at the correct height, it would appear)?

It's probably fairly clear I don't share the optimism of many here. Nor do I have much confidence in the specialist knowledge for these cars in the UK dealership system. I would bet money that my car will have had tap water put in it sometime in its 2 year life to date.

But even if that were not true, you are dreaming if you think ionic contamination doesn't grow in an aqueous system in contact with more than one metal. But maybe GM have genius metallurgists who have eliminated this by careful material selections, so rather than dwell on that too much I am going to run a test... the lab at work can run ionic contamination tests and I will see if I can get them to run some samples through, give me the proper numbers of what's in there. Should be an eye opener, one way or the other....
 
#25 ·
Yes, contrary to popular belief, water is not very conductive of electricity at all unless it is ionized with something like salt. The reason people get electrocuted in water is it creates a ground path from internals of electronics to the grounded copper pipes or earth ground, and even though water resistance is high, it only takes about 150 mA to stop a heart if conducted through them to ground, which is reachable with ionized water. GFCI circuits monitor the current coming into and out of the outlet, and if there is even a tiny difference between what is going in and out (ground fault, losing current to a ground not in the outlet) it shuts down the circuit.

Back to the coolant. You don't want coolant conductive, because if your car has a ground fault it can conduct into the coolant. When that happens through aluminum, little bits of aluminum are eroded away with each spark. This is called electrolysis. This causes pitting and other problems in the cooling system. The older and more wear materials in your coolant, the more conductive it becomes. This is why it is good to change your coolant regularly. Current 100k miles routines are to meet warranty requirements and such, not necessarily what is best for the vehicle.
 
#26 ·
Correct, there is no drain but a inspection port to check for leaks. I think that's what I was thinking about. I think doing the service, replacing the filter is a good idea since you have to remove the hose at the battery where the filter is any way.
 
#30 · (Edited)
I've been looking at this again, reading through the workshop manual.

I am not sure I can see any indication that the pump needs to be run for the battery/electrical coolant, nor any lifting gear used.

The battery coolant replacement appears to consist of;
-release lower radiator hoses, drain
-release battery hose under car, drain
-refit hoses
-vacuum purge/fill the system

No lifting, complicated removals, nor pumps to be run.

Am I missing something?

The engine coolant, on the other hand, looks problematic! I can't even see where there is an engine block drain!
 
#31 · (Edited)
You are probably referring to and older version of the procedure. It's been updated numerous times.There were problems getting all the air purged after draining and a special function was added to GDS2 (that runs the pump at various speeds and sequentially operates the 3-way valve) to alleviate the issue.
The hoses to be removed cannot be accessed from above, (hence the lift)
The only reliable source of information is eSI via the web and GM Globalconnect
WOT
 
#32 ·
Oh, I see. Thanks. Is that to help avoid these air bubbles they discovered were coming out of the battery cooling circuits of certain batches of cars?

Is it possible to get GDS2 or an equivalent at reasonable cost, or is it really something best not to fiddle with at all?
 
#33 ·
I know I'm resurrecting an old thread, but my 2012 is due for the coolant change in a few months.

Regarding the idea of not fully draining the battery coolant, here's my idea:

1. Disconnect the return line from the battery coolant reservoir, direct it to an empy bucket.
2. Apply 12v (or less) to the pump.
3. Keep adding new Dexcool to reservoir until it has gone through about 2 gallons.
4. Shut off pump, reconnect hose.

This would not fully replace the coolant in all of the circuits, namely the battery portion of the radiator and battery AC chiller, but would some of it and keep its properties (corrosion prevention, etc...) within an acceptable level, while removing contaminants in the old coolant.

I haven't looked yet, but if possible, draining and refilling the radiator with new coolant would be a separate part of the procedure.

Does anyone know how much coolant stays in the radiator or battery?
 
#34 ·
Did this a few times performing a do it yourself automatic transmission flush only did not need a separate pump.

I would worry about getting air in the system with this approach for changing the battery coolant. The cost of letting the dealership do it amortized over the 4 or 5 years should be insignificant. I would let them do it. Even though I like doing things myself, with maintenance on the Volt there doesn't seem to be a significant cost benefit.
 
#36 ·
Not a good idea. For one the coolant pumps are all pulse-width modulated devices. Even in the service information Volt technicians are cautioned NOT to directly connect 12V to the electric coolant pumps or damage may occur. The only way to safely over-ride the pump is to command a 95% duty cycle from a suitable scan tool.

Secondly, the primary issue is not draining the coolant, bit refilling it in a fashion that prevents air cavitation from occurring inside the battery or other high voltage component such as the power inverter module, on-board charger, cabin heater, or battery cells. If this localized overheating should occur the permanent damage WILL occur.

For that reason the only GM recommended process for coolant refilling in all 3 cooling loops is to use a Vac-N-Fil tool along with commanding the appropriate "coolant bleed" cycle from a suitable scan tool. This will both operate the pump at various speeds while it cycles the flow directional control valves in a sequence that is designed to purge all
air from each system and insure component damage a loss of isolation in the high voltage system wont occur.

Sorry but this simply isn't a "back-yarder" procedure and best left to the dealer

WopOnTour
 
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