[Allez]

Posted this about coolant levels on the maintenance forum with no response.

According to the manual 'Check to see if coolant is visible in the coolant surge tank . . . If coolant is visible but the coolant level is not at or above the COLD FILL line, add a 50/50 mixture of clean drinkable water and DEX-COOL coolant.'

So with the engine cold on my car, the top chamber is filled just about to the top, above the COLD FILL line. The bottom chamber has very little in it, maybe 3/4", and I don't see any fill line. Is this normal? I've read some places that the bottom chamber should be half full, but reading the manual multiple times it seems like maybe I don't worry about the lower chamber unless the top chamber isn't full? The instructions given to add coolant look like they are for either if the coolant is visible but not at or above the COLD FILL line, or if there is no coolant is visible in the coolant surge tank.

[SSDan]

The way I read the manual and interpret the diagrams is that I should keep the upper tank completely full and the surge/overflow (lower tank) filled half way. A couple of years go the surge tank on mine was dry. I added coolant per the manual and have been good ever since.

[Sweptwing]

Originally Posted by Allez

Posted this about coolant levels on the maintenance forum with no response.

According to the manual 'Check to see if coolant is visible in the coolant surge tank . . . If coolant is visible but the coolant level is not at or above the COLD FILL line, add a 50/50 mixture of clean drinkable water and DEX-COOL coolant.'

So with the engine cold on my car, the top chamber is filled just about to the top, above the COLD FILL line. The bottom chamber has very little in it, maybe 3/4", and I don't see any fill line. Is this normal? I've read some places that the bottom chamber should be half full, but reading the manual multiple times it seems like maybe I don't worry about the lower chamber unless the top chamber isn't full? The instructions given to add coolant look like they are for either if the coolant is visible but not at or above the COLD FILL line, or if there is no coolant is visible in the coolant surge tank.

This is correct. The upper tank must always be full 100% of the time. The bottom tank is the one you add fluid to to keep it between the marks (~ 1/2 full) which of course are hard to see.

Great design from an engineering standpoint to ensure there's no air in the loop, but horrible from a owner/maintenance standpoint.

This manual page shows the purge procedure as well as a good graphic of what the two tanks should look like under normal conditions (hot or cold).

[vtirocz]

Originally Posted by SSDan

The way I read the manual and interpret the diagrams is that I should keep the upper tank completely full and the surge/overflow (lower tank) filled half way. A couple of years go the surge tank on mine was dry. I added coolant per the manual and have been good ever since.

This is what I recall as well.

Allez, read through that section of the owners manual. It goes into good detail and spells out exactly the procedure for adding coolant. I believe the bottom tank also has a cold fill line if you look closely.

[ctrlz]

This recent thread had much to offer on the same topic:
https://www.camaro6.com/forums/showthread.php?t=574138

[MackSteelPrivateEye]

8-)

[Allez]

Thanks everyone. I've read through that section of the manual several times; what confused me was that the only part where is says to add coolant to the bottom reservoir is when the top reservoir is dry (at least the way I was reading it). Maybe I was being too literal. Anyway, it's easy enough to add to the lower one, although my old eyes can't make out a fill line there.

[acniv]

Just refilled mine after replacing the cooling fan, filled the top to the mark and bottom half way. Started the car, let the thermostat open, topped off the top tank, all good. used dexcool 50/50 premix from Peak I think was the brand.

[Yellow Beast]

I always wondered why GM put a tiny funnel in a bag in my trunk. Turns out that little funnel fits perfect in the hole for the second coolant tank

[UnknownJinX]

Originally Posted by Allez

Thanks everyone. I've read through that section of the manual several times; what confused me was that the only part where is says to add coolant to the bottom reservoir is when the top reservoir is dry (at least the way I was reading it). Maybe I was being too literal. Anyway, it's easy enough to add to the lower one, although my old eyes can't make out a fill line there.

I filled up mine a little bit, used up 300 mL(10 oz for Americans) of the mixture. My measuring cup made filling the bottom surge tank pretty easy. I just bought some AC Delco DEX-COOL, though I'd imagine anything DEX-COOL is fine. Colour will be a little different, factory fill is pink while coolant from botttles are orange.

As for the fill line for the bottom tank, if you look close enough, there should be a pinch in the plastic on the bottom tank near the halfway point, which you can use as a reference when filling up.

[TheRealJA105]

Originally Posted by Yellow Beast

I always wondered why GM put a tiny funnel in a bag in my trunk. Turns out that little funnel fits perfect in the hole for the second coolant tank

That's for putting gas in the tank with a gas can. Capless system has a second sealing plate that needs to be pushed open by the small funnel.

[Allez]

My DEX-COOL 50-50 arrives tomorrow, so will add it this weekend.

[Yellow Beast]

Well I'll keep using it for the coolant tank. Ive never run out of gas in my 36 years of driving.

[vtirocz]

Originally Posted by Yellow Beast

Well I'll keep using it for the coolant tank. Ive never run out of gas in my 36 years of driving.

Exactly - that's a good use for it!