What coolant should I use?

[SnowDrifter]

If you drain through the lower radiator hose and remove the heater core lines off the water pump, you'll get somewhere around 65-70% out of the system


From there, you'd essentially just check the volume of the system of your specific vehicle (rear heat, engine size, efan or mechanical, etc), add half that volume of concentrate, then just fill the rest up with distilled water. You'd mix it 'in vehicle,' not before you add it

I did mine that way, shot for 60/40, refractometer measured out at 59/41

 

[Fless]

If you drain through the lower radiator hose and remove the heater core lines off the water pump, you'll get somewhere around 65-70% out of the system


From there, you'd essentially just check the volume of the system of your specific vehicle (rear heat, engine size, efan or mechanical, etc), add half that volume of concentrate, then just fill the rest up with distilled water. You'd mix it 'in vehicle,' not before you add it

I did mine that way, shot for 60/40, refractometer measured out at 59/41

^^ This is the right way to get the correct mix. Works perfect every time.

 

[JamesLond]

If you drain through the lower radiator hose and remove the heater core lines off the water pump, you'll get somewhere around 65-70% out of the system


From there, you'd essentially just check the volume of the system of your specific vehicle (rear heat, engine size, efan or mechanical, etc), add half that volume of concentrate, then just fill the rest up with distilled water. You'd mix it 'in vehicle,' not before you add it

I did mine that way, shot for 60/40, refractometer measured out at 59/41

OK. I planned to just remove the thermostat, run the engine 5 or 10 minutes, then drain. Is it still necessary to fill from the upper rad hose under these conditions?

Also, in the manual, I see that the cooling system capacity is 14.4qts for 5.3L with front A/C and 15.8qts for 5.3L with front & rear A/C. How can I tell what I have?

 

[gooffeyguy]

OK. I planned to just remove the thermostat, run the engine 5 or 10 minutes, then drain. Is it still necessary to fill from the upper rad hose under these conditions?

Also, in the manual, I see that the cooling system capacity is 14.4qts for 5.3L with front A/C and 15.8qts for 5.3L with front & rear A/C. How can I tell what I have?

Do you have controls for rear Hvac, located on the back of the center console or on the overhead console (depending what year/trim you have)

You can also look under the hood where the heater hoses go to the firewall and look to see if they T off towards the passenger side with metal lines that run to the back.

 

[Blackcar]

This is just what I do on getting mix correct. I have extra empty gallon of distilled water, so I get new gal. bottle of distilled water spit the water equally then take a new gal of antifreeze and split that to fill distilled bottles evenly .and if any amount left put back in antifreeze jug and mark it 50/50 for top offs etc. I have always liked to use distilled water for mix just me.

 

[JamesLond]

Do you have controls for rear Hvac, located on the back of the center console or on the overhead console (depending what year/trim you have)

You can also look under the hood where the heater hoses go to the firewall and look to see if they T off towards the passenger side with metal lines that run to the back.

I see where they T off. Looks like I do have rear A/C. Thanks.

 

[SnowDrifter]

OK. I planned to just remove the thermostat, run the engine 5 or 10 minutes, then drain. Is it still necessary to fill from the upper rad hose under these conditions?

Also, in the manual, I see that the cooling system capacity is 14.4qts for 5.3L with front A/C and 15.8qts for 5.3L with front & rear A/C. How can I tell what I have?

it's honestly easier just to remove the lower radiator hose. If you disconnect the heater core lines too, you'll get maybe an extra 3oz out of the system by removing the tstat. Meh, not worth it.

The heater core lines are the ones coming out of the passenger side of the water pump. Best done at the water pump that the firewall fitting, IMO.

These ones.


Follow them up to the firewall, and see if they go straight in, or have another set of metal lines that carry them down towards the lower-passenger side of the car. If you have the extra metal lines on there, it's 15.8qts

 

[JamesLond]

it's honestly easier just to remove the lower radiator hose. If you disconnect the heater core lines too, you'll get maybe an extra 3oz out of the system by removing the tstat. Meh, not worth it.

The heater core lines are the ones coming out of the passenger side of the water pump. Best done at the water pump that the firewall fitting, IMO.

These ones.


Follow them up to the firewall, and see if they go straight in, or have another set of metal lines that carry them down towards the lower-passenger side of the car. If you have the extra metal lines on there, it's 15.8qts



View attachment 366447
View attachment 366449

It looks like 7.9qts which seems to convert to 1.975 gal. So that's around 2 gallons of straight dexcool.

Wow, that seems like so much coming from driving smaller cars.

 

[Fless]

Your system, if it has rear heat, will hold nearly 4 gallons of coolant. So you'll need at least 2 gallons of concentrate to get to a 50/50 mix. If you want a 60/40 mix, then you'll need a bit more than 2 gallons of concentrate.

 

[JamesLond]

it's honestly easier just to remove the lower radiator hose. If you disconnect the heater core lines too, you'll get maybe an extra 3oz out of the system by removing the tstat. Meh, not worth it.

The heater core lines are the ones coming out of the passenger side of the water pump. Best done at the water pump that the firewall fitting, IMO.

These ones.


Follow them up to the firewall, and see if they go straight in, or have another set of metal lines that carry them down towards the lower-passenger side of the car. If you have the extra metal lines on there, it's 15.8qts



View attachment 366447
View attachment 366449

So you're saying that I don't need to remove the thermostat to do the flush? I tried to pull it out of the housing, but it seems pretty stuck in there.

Also, how do you know when to stop filling the upper rad hose? I forgot to remove the thermostat at this point, but I put about 1.5gal water in the hose and then I started up the car. After a little bit, I started to see the low coolant message so I freaked out and added a 1/2 gal at the reservoir. Saw light smoking from the front of the engine after letting it run 5 mins.