Refilling coolant system how-to?

[greiswig]

Having just replaced all the plastic bits and water pump and thermostat on my 2016 SCV6, I'm wondering how I can make sure I've gotten coolant throughout the system, and gotten the air out before I run it. Last thing I want to do is end up with enough cavitation in the water pump that it isn't circulating through the heads.

The service manual only describes how to do it using their own special vacuum tool, but doesn't show illustrations or anything.

Anyone have the secret recipe for how to do this properly?

 

[jlglr4]

There is a manual bleed method in the manual, which is what I did. Here’s the rundown:

(1) Get the coolant reservoir free and raise it up about 1.5”. You can’t raise it up much, but it doesn’t take much. Just need the rim higher than the highest bleed point. I think I lifted it a bit, and just put something underneath it to hold it up. Manual says to remove the headlight to get the reservoir free, but I don’t think that’s necessary.

(2) Open all the bleed points. There is one on the front crossover (plug), one near the firewall, one on the tube leaving the top of the radiator, and one on the reservoir itself.

(3) Fill the reservoir all the way up and watch for coolant at the first bleed point (front crossover). Once that starts bleeding, cap it.

(4) Keep filling until you see coolant at the second bleed point near the firewall. Close that bleed point.

(5) Close the bleeder on the reservoir. You now have just the radiator tube bleed open.

(6) Start and run the engine. Continue to top with coolant and watch for coolant at the radiator tube bleed point. Once it bleeds, close it.

(7) Turn the motor off and wait at least a minute. Top up the coolant if needed.

(8) Turn the heater controls to maximum and restart the car.

(9) Hold the RPMs at 2000 until the coolant level in the expansion tank drops.

(10) Increase to 3500 RPM until hot air is emitted from front and rear face vents. Keep an eye on the coolant level and keep topping up a couple inches above the cold fill range. Also watch your temp gauge - make sure something isn’t going awry.

(11) Let it idle until the coolant level stabilizes - hot air should still be coming out of the vents.

(12) That’s it. Shut it off and reinstall the reservoir. Top it up just above the cold fill if its not already there and check it frequently for the first few drives.

 

[greiswig]

This is great, @jlglr4 ! Thank you.

I think I see the 4 bleed ports: there is one on the metal section of coolant line right near the main battery, one on the plastic crossover above the throttle body, one on the reservoir, and one on a plastic elbow right next to the reservoir. Is that right?

I also have a pressure tester, and I’m wondering if that can be used to push the coolant into the system without raising the reservoir. There is so much stuff in that compartment that even seemingly trivial unfastenings seem to become difficult pretty quickly.

 

[jlglr4]

Seems like you should be able to get a pressure unit to work, but not entirely sure. If it’s just pressurizing and not delivering coolant to the reservoir, you’ll have to disconnect and add coolant rather than being able to pour it in as the process is running. You also could just rig another gravity feed reservoir on top somehow, and suck out the excess when you’re done.

But, really, I don’t remember much trouble getting that reservoir lifted up. As I recall, just two bolts that you can reach with an extension, the wiper fluid filler neck just has a clip holding it, then lift up (there is a little rubber grommet or hook stabilizing on one side that just pulls out). Pulling the headlight is easy as well if you want better access. Since you are just raising 1.5-2.0”, you don’t need to get it totally clear to come out entirely.

Hey - that reminds me - did you happen to measure your normal engine temp before you did this work? I didn’t and wish I had done so to confirm my temps before and after are the same. I’ve never been able to get good data points (from others) as to the normal running temps on the SCV6 engine. From the manuals discussion of opening temps for the t-stat in the SCV6 manual vs the earlier cars, looks like they run a hotter t-stat.

 

[greiswig]

I did not measure the actual temperature beforehand, no. I did note where on the instrument temp gauge things tended to sit. I'm happy to measure afterwards, assuming I'll be able to get the engine running now.

 

[mbw]

The vacuum method is super easy. Just buy this and have an air compressor handy. Very easy to use. I can drain the coolant and fill it back up in 5 minutes and never have any issues. I've never touched a single bleed point on my LR4.

https://www.amazon.com/gp/product/B01BW39HJS/

Edit: Just to be clear. All you do is drain the coolant from the lower radiator coolant pipe or whatever... You just take the cap off the reservoir and put this on. You run the compressor and the venturi valve thing creates a vacuum. You pull -25 or so and then you can shut off the compressor and shut the green valve and it should hold pressure pretty well.. you can check for leaks with that. Then you just open the other valve and it pulls coolant into the system and fills up the reservoir. Sometimes it fills it up a little too much but you can just suck some out. Done!

 

[mbw]

 

[BostonBill]

For the OP did you find a good YouTube for the thermostat DIY? I’ve replaced them on other cars and was just going to wing it. I’ll be doing mine soon as well as upper and lower hoses. And jglr great bleed write up thank you. I’ll take a before and after engine temp for you and post back here. MBW I’ll be getting that pressure bleeder for sure. Thanks. Great thread guys. Just what I needed.

 

[greiswig]

For the OP did you find a good YouTube for the thermostat DIY? I’ve replaced them on other cars and was just going to wing it. I’ll be doing mine soon as well as upper and lower hoses. And jglr great bleed write up thank you. I’ll take a before and after engine temp for you and post back here. MBW I’ll be getting that pressure bleeder for sure. Thanks. Great thread guys. Just what I needed.

Didn’t really look for a YouTube on replacing the plumbing and thermostat. Take some pics before disassembly so you can have a reference, and only disassemble at the break points where the new “modules” have break points. But it would be pretty hard to mess up assembly.

oh, and get hose clamp pliers.

 

[BostonBill]

Here’s current temps. I’ll post again after I change the tstat