Afternoon everyone,

I've got a question regarding my coolant and that dreaded waterfall sound. From reading around here I know I likely have air trapped in my coolant system and need to flush it. My question is what type of coolant should I be adding? I can' tell what is in there currently and have included a picture here of the expansion tank.


Thanks in advance for the help.

 

Regular ol green coolant which you have none of. Flush that out before you add anything to it. That has a cold coolant level mark somewhere on the outside and you need to keep it at that mark. If the rest looks like crap I'd flush the whole cooling system too. I would not add good to bad and hope for mediocre. When you do burp the cooling system keep that tank nearly full until all the air is out. Get the passenger side front up high and remove the bung from radiator to allow air to escape while running. Keep eye on expansion tank during process. 1 gallon of regular full strength green coolant with 1 gallon of distilled water at 1:1 which gives you two gallons of 50/50.

 

How do I drain it completely and flush it as well? I have the RAVE manual but this is the first time I've really gotten hands on with a vehicle beyond standard oil changes.

And do I understand I keep the expansion tank completely full while its 'burping' and once the air is out it settles down to the normal level?

Will the two gallons be enough for the entire system as well?

I thought that the level was low there but when I purchased it I had a mechanic run a pressure test on it and he said there wasn't any leaks. With it being that low how is it able to maintain a good temperature reading, which it does?

 

Need 3 gallons of mixed anti-freeze if you get every drop out of the system. So get 2 gallons of each - green anti-freeze/distilled water. Mix in a 5 gallon clean bucket.

Draining is a pain, must remove bottom radiator hose, that empties the radiator and heat exchanger. The motor is tougher because the thermostat is closed, I remove the thermostat and drain and flush the motor separately. Flushing is easy, use a garden hose in top radiator hose, motor with thermostat off and set hose in thermostat opening. Flush till clean. Might as well change the thermostat while your there, gasket is optional.

Because I've done this so many times I'm skipping stuff that's obvious to wrench types. When you have the radiator and motor flushed of old coolant button it back up. Remove the radiator bung and begin filling the system from that opening. Once the coolant is high but not to the top of the radiator start the motor, keep filling it with coolant through the bung opening until it settles displacing air. When you think you have a decent amount of air out of the system then tighten the bung and start filling the expansion tank, keep it at least 3/4 full and maintained for awhile.

 

Great I'll give it a shot filling it with coolant and then trying to purge the air from the system.

Thanks for the help!

 

No problemo, enjoy your new Disco! As always, I'll be here when you have more questions......

 

ihscouts,

Do you have a recommended brand of coolant? Or will any green do?

 

Any green by me is good enough.

 

Scouts,

Why does the RAVE say it is "not desirable to flush through system, after draining"?

This seems to suggest just draining the system from the radiator, reattaching hose and then filling it back up/burping it?

 

Um, you skipped the fact that that "Note" is talking about the "heater core" only and not the entire cooling system. Don't skip details cuz it gets everyone riled up in a panic and starts mass rioting in the streets......

NOTE: It is not possible to drain all coolant
retained in heater system. It is not
desirable to flush through system, after
draining.

So skip flushing the heater core. See how simple life is?

What's in the bottom of your expansion tank, think maybe it might be worse at the bottom of the heater core since it's lower? Yep, most debris settles there cuz it's just a little lower and backwater than the expansion tank. If you dislodge too much of it it can block the cores of the heater matrix. Then once the system is up and running the heat alone can cause steam in the air pockets and bingo, the heater core gives way. This is worse case.

Do the best you can eh. If it's been awhile since the cooling system has been serviced you could do two flushes and a fill or just drain and refill. Either way it's better than nothing at all.