Collant flush with hose for new radiator (1 Viewer)

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Hi there,

One more fellow with a question, after weeks of research, about flushing the coolant system with a garden hose so any help is definitely appreciated.

I have been working on refreshing the coolant system in the LX450 as it came with the wrong green coolant :bounce:. The rig has around 232kmi in it and after spending a lot of time reading the FSM, this forum, the internet, watching youtube etc. I have decided to flush and refresh almost the entire coolant system with some new parts. The water bypass pipe above the thermostat housing is leaking but other than that, nothing has broken yet just preventive maintenance because of the mileage (232kmi), the hoses are far long gone and the radiator is about to crack big time.

So I drained the green coolant from both the petcock and through the engine drain plug, the fluid seemed to be somewhat new as it was pretty clean and clear with few minor thin chunks that came out of the engine block. Then I got the old "yellow about to fall apart" radiator with the big hoses out and the next step on the list is to flush the engine and that is why i'm writing in here today. Maybe someone can shed a light on the question.

I got distilled water to flush everything but since the radiator and hoses are out, I have decided to flush the system with a garden hose first to remove any gunk that could still be there (and to save the distilled water) and then flush everything again with the distilled water. I used the old rad. hose as an adaptor so I could insert the garden hose close to the thermostat housing and attached another old rad. hose to the outlet pipe so water doesn't fall on the alternator. See attached pic.

With everything connected and ready to go, I first turned on the garden hose just a tad so pressure doesn't blow water on the thermostat but enough to fill the pipe that goes to the thermostat, turned on the engine and waited. To my surprise, nothing came out of the outlet pipe and after some 5-10mins I start to hear a continuous beep like noise coming from the front of the engine bay :clap: maybe dry water pump. The beep sound was getting louder so I, of course, turned everything down and pause for more research. Everything looks fine and after some time I tried again but water wasn't been pulled through the system.

So the question is, how are you folks connecting the garden hose to flush the engine? Is there also a need to connect the garden hose to the heater pipe by the firewall to flush the heat system and engine block? Last but not least, after months researching the PHH replacement, is there a video or steps on how to replace that nasty little hose? I have found some material but nothing really effective. I will try to attack it as I'm working on the coolant system but man'o man.....that little guy is tough to reach and replace. From what I have seen, people say that the pipe connected to the heater valve control should be disconnected so the bottom portion where it connects to the metal pipe before the PHH can be disconnected. Only then, the little PHH can be disconnected. Does that sound like the way to go?

Any help is much appreciated. :beer: Thanks!

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Nothing wrong with Green coolant. If it was clean and didn't look like it was mixed with Red i'd just stick with that.

The bad thing is when you don't completely flush out one or the other and mix them.
 
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Nothing wrong with Green coolant. If it was clean and didn't look like it was mixed with Red i'd just stick with that.

The bad thing is when you don't completely flush out one or the other and mix them.

Thanks for the heads up. I heard exactly what you mentioned about the green coolant being acceptable on the 1FZFE engine as long as it is not mixed with the red coolant but as I got a leak on the water bypass pipe, have to replace the radiator, other minor parts and hoses, I have decided to replace the green coolant and add red as stated on the FSM and it is easier to work on the system without coolant.

Either way, thanks for the msg. Peace
 
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You need to remove the thermostat to flush with a garden hose. Otherwise, the T-Stat i closed and nothing goes anywhere. The noise you heard is probably air pushing through the bleed hole in the t-stat.

Also, you DON'T want to seal the hose into the system because the hose is typically at 65 PSI and they system is only designed for 14 PSI. You could cause more problems.

I flushed mine in all directions, in and out of every orifice, with the t-stat out and the radiator out, all with the garden hose just shoved into the end of the hose and allowed it to flush backwards if it did.

Then I closed it all up WITHOUT the T-Stat, filled it with distilled water, then drove it for (6) days, dumping and refilling with distilled at the end of each day.

Then I drained, installed the T-Stat and filled with coolant.

Make sure you burp the system with the front of the truck up on a curb or set of ramps.
 

80ways

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For what it's worth, when I flushed mine and left just distilled water in for a few days of driving to complete the flush, I ended up with a bit of orange (rust) tint in the water. I didn't flush daily like Bilt4me wisely did.
Also, plain water doesn't have the lubricant properties for the water pump and its seals, so it's probably best not to drive it for too long that way unless you add water wetter or similar product. YMMV.
 
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You need to remove the thermostat to flush with a garden hose. Otherwise, the T-Stat i closed and nothing goes anywhere. The noise you heard is probably air pushing through the bleed hole in the t-stat.

Also, you DON'T want to seal the hose into the system because the hose is typically at 65 PSI and they system is only designed for 14 PSI. You could cause more problems.

I flushed mine in all directions, in and out of every orifice, with the t-stat out and the radiator out, all with the garden hose just shoved into the end of the hose and allowed it to flush backwards if it did.

Then I closed it all up WITHOUT the T-Stat, filled it with distilled water, then drove it for (6) days, dumping and refilling with distilled at the end of each day.

Then I drained, installed the T-Stat and filled with coolant.

Make sure you burp the system with the front of the truck up on a curb or set of ramps.

Hello again BILT4ME. Thanks for the info, very helpful!

I didn't mention on the initial post but I did remove the thermostat after removing the radiator. The only thing I can imagine is that probably as I slightly open the garden hose and not full blasted it, the water pressure out of the hose wasn't enough to push water through the thermostat housing, water bypass pipe and water pump.

I got other pipes to connect to the lower hose and maybe this time the water will reach the top of the engine. Will try again now and see how it goes. This time with the engine off.

Thanks again!
 
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BILT4ME and Kernal, thank you so much for the info!! :beer::beer:

It worked! No need to turn the engine on, that was new to me. Thanks for the tip on that one. Flushed both ways with the garden hose and everything is coming out clear.

Interesting to see that even though there was clean water coming out of the outllet pipe, the reverse flush still purged some green coolant mixed with water. It makes me wonder, the reverse flush is probably the best and most efficient way to really flush the entire system. However, what would be the reason for the reverse flush to spit water with coolant? :hmm: Thoughts anybody?

Well, next step is to add the distilled water and go for a drive for a few days after the radiator is in place. Thanks again!
 
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Turbulent vs laminar flow and pockets of coolant stuck in areas that laminar flow passes in one direction, but become turbulent when flow is reversed.

That's my story and I'm sticking to it....

Crap stuck over the fins that won't push though one way but it will the other way.

That's MY story and I'm sticking to it! ;) :rofl:
 

MoJ

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Turbulent vs laminar flow and pockets of coolant stuck in areas that laminar flow passes in one direction, but become turbulent when flow is reversed.

That's my story and I'm sticking to it....

That is a great story, thanks for sharing Rusty Marlin!
 

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