Cooling system flush & burping coolant: what's your process? (1 Viewer)

[PapaGoose08]

I did a coolant flush a month or so back and replace the heater "T"s at the same time.

I was having an issue where heat wasn't coming into the front heater, so I wanted to back-flush the front heater core. I saw several posts where people use their garden hoses and that probably works just fine. But I was concerned about the pressure and also wanted to use distilled water so I used a 4-5 ft length of hose and funnel to gravity feed water back into the heater core similar to the way a beer bong works if you are familiar with one of those. Because the hose was clean and I was just pouring distilled water through, I also blew into the hose a little bit as the water was going in to add just a bit of pressure.

It worked really well and got my heater going again. A bunch of "silt" came out of the heater core, so I am guessing that is what was plugging it up.

I refilled with Toyota SLL from the dealer which was probably a waste of money. I think I go with Zerex next time.

 

[jpoole]

My thought on distilled vs tap is that it's really important for water left in the system for a long time but not that important for initial flushes. I'm basing this opinion in part on years of operating a raw water cooled gasoline engine in a sailboat operated in salt and brackish water. The minerals start to cause problems when combined with heat and/or long-term exposure primarily and I've seen what is probably the worst-case scenario for an engine cooling system (running inland/coastal salt water) and am still running the engine after 44 years in salt water. Boiler scale type buildup that occurs when the engine is at operating temp is the main issue though depending on what's in the water and what metals are involved/etc. a variety of electrolysis and scaling/build up problems are possible with or without heat.

If a thorough flush is needed after long neglect or for a coolant type change I think that using tap water is a great option and that it would be hard to be as thorough with the flushing if distilled only was used. If you want to be on the careful side avoid leaving the tap water in the system for full heat cycles or any period beyond a thorough flush. Follow-up flushing using distilled water to get the tap water out of the system after your initial flush should minimize any risk. Depending on the scenario connecting a shop-vac to blow air through the cooling system for a while could be a way to remove more of the tap water and avoid deposits being left before an engine is left empty for a while or as an extra safeguard to get tap water out of the system.

In any case, I think that the manual is specifying distilled/de-mineralize water be used when filling the system for an extended period. Short flushes rarely involve the engine getting up to full temp as so much cool water is being introduced and are typically drained/replaced shortly so it's a very different scenario and the scaling/electrolysis risks of hard water seem minimal.

 

[Spike555]

I've never used distilled water - just water from the city tap.
We don't have hard water or much lime in it anyway.

I do it like this:
- Open Radiator Drain at bottom of Radiator and let fluid start draining out.
- Open Radiator Cap and insert Hose from City Water into Radiator.
- Crank Engine with Heater on and let water flush out for a few minutes.
- Remove City Water hose and let more water drain out radiator.
- Close Drain at bottom of Radiator.
- Pour in a couple gallons of 100% Antifreeze
- Crank Engine and let it run for a few minutes
- Add more Antifreeze or water as Radiator level goes down.
- Button up and take for Test Drive.
- Next day when cool check Radiator and top off.


So what is the down side of doing it this way??????

Yes, 100% antifreeze has a lower boiling point than plain water AND a higher freezing point than just plain water.
Think of antifreeze as one half of an epoxy, it will not work unless you mix it with the other half of the epoxy, in this case water.
A 50/50 mix will get you a freeze point of -34*F and a boiling point of 265*F, you can raise or lower the freeze point by changing the mixture, NEVER go over a 70/30 (antifreeze/water) mixture.
Also, without adding water the seal conditioners, water pump lubricant and corrosion inhibitors will not be properly activated.
Yes 100% antifreeze is cheaper than the 50/50 premixed, but the premixed is idiot proof and if used as directed comes with a warranty that protects your engine.

 

[Spike555]

Deionized vs Distilled Water for Radiator | Mechanical/Maintenance Forum | Bob Is The Oil Guy

Coolant and Distilled Water | Mechanical/Maintenance Forum | Bob Is The Oil Guy

I've been using the garden hose to flush my cooling systems for as long as I've been alive. Never had a problem. Your results may vary.
I have also used the garden hose to mix my coolant, but I do prefer the premixed because then I don't have to think about it, i just pout it in and go.

 

[abuck99]

The garden hose method will save a lot of time, but I’m in the camp where adding mineral contaminant to the cooling system circuit is something Ill take care to avoid when possible.

I did a distilled water flush yesterday and it took about 2 hours. Drain coolant- radiator and engine block drains, remove T stat, refill w/ distilled water, run for about 10min drain and repeat until the clear water drains from cooling system. Took about 10 gallons of d water in 3 flushes.

Time consuming to run, heat up, cool down, drain 3 places, and repeat.

 

[feza]

This is how I do it, drain coolant, stick garden hose into radiator, remove upper hose from radiator leaving attached to the engine.
Turn on hose.
Start the engine, turn on heater.
Let engine run until nothing but clean water comes out of upper hose.
Shut off engine. Leave hose running until it comes out cold.
Turn off hose. Drain cooling system of water.
Put upper hose back.
Fill with Prestone Universal 50/50. Bleed the system. Fill overflow tank to the brim.
Drive normal, check system level after a few days with engine stone cold.
Fill overflow to the brim one last time.
Done.

I've been doing it this way for 20+ years and it works every time. I have never had a cooling system problem, well, except when the water pump seized and sent my fan through the radiator on my Land Rover, but that was my own fault and a story for another day.

First never put city water in coolant system, distilled only

This is the procure that I always use. Are the maintenance nazis upset about having 100% non-DI water in the system for a few minutes? or about the residual few ounces left after the flush?

Would a through garden hose flush followed by a quick DI flush, drain and fill with premix be less offensive?

 

[2001LC]

@ferza your welcome as anyone to your opinion/procedure. But keep your "nazis" slurs to yourself! This forum is no place for that BS!

Go back and read: NEW members! Welcome! Read this first!

 

[cwmoser]

@ferza your welcome as anyone to your opinion/procedure. But keep your "nazis" slurs to yourself! This forum is no place for that BS!

Go back and read: NEW members! Welcome! Read this first!

Are you serious?
There's nothing offensive with what @ferza stated.

 

[feza]

@ferza your welcome as anyone to your opinion/procedure. But keep your "nazis" slurs to yourself! This forum is no place for that BS!

Go back and read: NEW members! Welcome! Read this first!

I am sorry 2001lc, I meant no offence, and I love your quality restore build threads. I will be flushing my 80 and 100 next weekend and legitimately would like to know what which aspect of the garden hose water touching the cooling system you object to. I was joking that you do a much better job on your trucks then I ever do. Let me rephrase.

What are the people who do high quality maintenance, way above and beyond what this drunk shade tree mechanic does, upset about? having 100% non-DI water in the system for a few minutes? or about the residual few ounces left after the flush?

 

[2001LC]

Offense was taken, especial on this of all days. Your apology excepted!

Yes the small amount of minerals is left behind from tap water. But it actually closer to one gallon liquid remains on the average flush with rear heater, even when opening all three drains. Even the Dealers mechanical flushing machine can't get all the fluid out. I know some tricks to get most out, but not all (1 to 2 qts).

Chemicals in coolant attach to minerals in water, creating deposits. These deposit attached to wall of cooling system. They then clog and eat away at points of contact/attachment. This action also speed up the time to coolant becoming acidic, and electrolysis insues. If you ever have your front heater core (big job) leak in a 100 you'll wonder, was it the water! I've repaired enough coolant systems to have seen the damage first hand on/in radiator, heater core, blocks, heads, hoses, etc... We once thought is was just the way it was with coolant systems. We now know it was the tap water.

Google is a great research tool, do your homework.

 

[Spike555]

Offense was taken, especial on this of all days. Your apology excepted!

Yes the small amount of minerals is left behind from tap water. But it actually closer to one gallon liquid remains on the average flush with rear heater, even when opening all three drains. Even the Dealers mechanical flushing machine can't get all the fluid out. I know some tricks to get most out, but not all (1 to 2 qts).

Chemicals in coolant attach to minerals in water, creating deposits. These deposit attached to wall of cooling system. They then clog and eat away at points of contact/attachment. This action also speed up the time to coolant becoming acidic, and electrolysis insues. If you ever have your front heater core (big job) leak in a 100 you'll wonder, was it the water! I've repaired enough coolant systems to have seen the damage first hand on/in radiator, heater core, blocks, heads, hoses, etc... We once thought is was just the way it was with coolant systems. We now know it was the tap water.

Google is a great research tool, do your homework.

So if there is a full gallon of water left in the cooling system, then why is it when I fill my system with 50/50 premixed Prestone, with a freeze point of -34*F, I still have a freeze point of -34*F? The gallon of water left over would be more than enough to raise the freeze point well above the -34*F of the premixed.
And yes I test the freeze point of my cooling system with a tester.
While I do agree 100% that there is residual water left in the cooling system, I disagree with the amount being left.

 

[PADDO]

..... But it actually closer to one gallon liquid remains on the average flush with rear heater, even when opening all three drains. Even the Dealers mechanical flushing machine can't get all the fluid out. I know some tricks to get most out, but not all (1 to 2 qts).

Agree with @2001LC assessment of approximately 1 gallon residual coolant/water/whatever in the system. Having recently done a coolant changeout, thermostat, hoses and radiator cap I measured just shy of 12 quarts (16q system) draining from the radiator, engine block drains and thermostat housing.

 

[Julian Stead]

Strange how things are so different on this side of the pond, I have never heard of anyone using distilled water in a engine until I came to this site. I do agree with what is said but I changed the coolant using tap water yesterday and it won’t bother me in the slightest. Our water does come from the Brecon Beacons and if it is good enough to make single malt whiskey then it is good for the 100. Batteries is all I thought it was used for, that is from college to 3 dealerships, good old tap water has been used over and over again.

 

[bucfl]

So if I don’t have water I can use whiskey?

 

[Julian Stead]

Drink the whiskey and then you won’t care what goes in the motor, haha.

 

[abuck99]

Strange how things are so different on this side of the pond, I have never heard of anyone using distilled water in a engine until I came to this site. I do agree with what is said but I changed the coolant using tap water yesterday and it won’t bother me in the slightest. Our water does come from the Brecon Beacons and if it is good enough to make single malt whiskey then it is good for the 100. Batteries is all I thought it was used for, that is from college to 3 dealerships, good old tap water has been used over and over again.

I dont think it's that different here. Consensus here is most people flush with tap water & move on. I doubt very much that dealers or corner shops use anything but tap water either. Best practice for us anal over-maintainers (me included in this) would be the OCD route and use distilled water. I replaced my water pump (among other things) over the weekend, and was very happy with the state of water pump, and related fitting & passages- everything was quite shiny. No pitting, no corrosion, no visible scale with the exception of the O-ring, that recessed groove had a little build up from the O-ring beginning to leak. I didn't do the last flush, had a shop do it and I need to verify if they used the BG cleaner product & machine to flush, or used a garden hose. It had only been 30 months/21,000 miles and the fluid looked very good. It was Toyota SLL2.

As discussed in other threads the change interval is the key to healthy cooling system. These trucks are up to 20 years old now. As engines age they loose cooling efficiency with deposit build up, no amount of flushing can eliminate all of it and so its important to flush more often on older high mileage engines than on a new vehicle. Coolant chemistry is affected faster as well so it breaks down sooner, does not protect as long. I think every 3 years/36,000 miles would be early PM, 5 years 60k would probably be the longest I'd go.

So if there is a full gallon of water left in the cooling system, then why is it when I fill my system with 50/50 premixed Prestone, with a freeze point of -34*F, I still have a freeze point of -34*F? The gallon of water left over would be more than enough to raise the freeze point well above the -34*F of the premixed.
And yes I test the freeze point of my cooling system with a tester.
While I do agree 100% that there is residual water left in the cooling system, I disagree with the amount being left.

As for left behind water from flushes, I would agree that its close to 3 quarts to 1 gallon- I pumped coolant into the cores through the heater T's and got about that much water out before coolant started coming out. The rear heat system holds a fair bit and the lines also. I would say the chemistry would certainly be diluted if a proper flushing of the heater core(s) was done as this would leave clear water in the system if not purged- that would reduce your overall temperature protection by maybe 25% . If you're using one of those cheap float testers to check your concentration for temperature protection, I doubt it is accurate enough to determine a 8-10 degree difference.

 

[Julian Stead]

I have to say that my OCD doesn’t let the coolant stay in the system for more than 2 years, plus it has partial changes in between as there is always some reason to drop a hose off which then I will drain off the radiator and add new. My coolant change was on my corolla but I done a radiator drain and refill on the 100 a few weeks ago when I done my alternator as I found out it won’t drop out to the the floor due to being RHD and the power steering pipes where in the way so I lifted the radiator out to give me loads of room. But this partial change doesn’t alter when I next do my flush which is going to be in the summer.

 

[Spike555]

Whenever I baseline a car I flush the cooling system using the garden hose, after that is is just a drain and fill every two years.

 

[Sacto60]

This is how I do it, drain coolant, stick garden hose into radiator, remove upper hose from radiator leaving attached to the engine.
Turn on hose.
Start the engine, turn on heater.
Let engine run until nothing but clean water comes out of upper hose.
Shut off engine. Leave hose running until it comes out cold.
Turn off hose. Drain cooling system of water.
Put upper hose back.
Fill with Prestone Universal 50/50. Bleed the system. Fill overflow tank to the brim.
Drive normal, check system level after a few days with engine stone cold.
Fill overflow to the brim one last time.
Done.

I've been doing it this way for 20+ years and it works every time. I have never had a cooling system problem, well, except when the water pump seized and sent my fan through the radiator on my Land Rover, but that was my own fault and a story for another day.

youre replacing the rad drain plug before you run the garden hose, right?

 

[2001LC]

Please don't use a garden hose to flush coolant systems, your rig may end up in my shop one day. I hate dealing with the effects of minerals in the 2UZ-fe engine coolant system. Distilled water only (de-mineralized water only).