Coolant Flush Procedure (1 Viewer)

[dbla]

Hey All,

Going to be assembling the rest of my 3FE tonight and hopefully flushing and filling with coolant.

I'm not getting a clear consensus when I search on the best procedure for doing this.

Currently, the thermostat is NOT installed, my plan was to close up the thermo housing and flushing before installing the new thermostat.

Where is the best place to run water through the system? I've heard some folks say the radiator, others the thermostat housing... I'm not super clear on what I should be doing.

Next, once it's running clear, what is the best procedure for draining the water fully and then refilling coolant?

Just pull the petcock on the new radiator and let it drain/run for a few?

Thanks and appreciate any advice or guidance you can offer. Hopefully this is nearly done.

-A

 

[cruisermatt]

Literally just drain it and refill it. There is nothing special here

 

[dbla]

Literally just drain it and refill it. There is nothing special here

So just pull the radiator petcock, let it all run out, then refill the radiator??

Don’t I need to let it run and flush heater cores and what not?

 

[cruisermatt]

Dude just pull the radiator hoses and take a garden hose to to the motor and and radiator. Same thing with the heater core.

 

[Seth S]

Unless the engine was sitting in a field for 30 years or suffered some sort of massive head gasket failure and the passages are full of oil sludge there shouldn't be any real need to flush the coolant. If its just the need to change out the old coolant with new then open the drains....fill it back up with Deionized water and run it untill its warmed up and the T stat has cycled a few times.....if you stand at the drivers fender with your face in the air stream from the cooling fan you should be able to feel when the air coming out gets hotter and cooler (wearing safety glasses is a good idea). Then shut it off and drain it....fill it back up with the proper coolant/denatured water mix and good to go.

My personal feeling is the the "coolant flush" was the creation of auto garages 75 years ago as a money making opportunity to sell to the unaware public.

 

[dbla]

Dude just pull the radiator hoses and take a garden hose to to the motor and and radiator. Same thing with the heater core.

Hey Matt,

I appreciate your trying to help but this is my first project on this LC. It's also my first time getting into the cooling system on an engine at all. SO when you say "take a garden hose to the motor and radiator," I am assuming you're not literally telling me to hose down the motor and radiator... so that's what I am trying to clear up.

 

[dbla]

Unless the engine was sitting in a field for 30 years or suffered some sort of massive head gasket failure and the passages are full of oil sludge there shouldn't be any real need to flush the coolant. If its just the need to change out the old coolant with new then open the drains....fill it back up with Deionized water and run it untill its warmed up and the T stat has cycled a few times.....if you stand at the drivers fender with your face in the air stream from the cooling fan you should be able to feel when the air coming out gets hotter and cooler (wearing safety glasses is a good idea). Then shut it off and drain it....fill it back up with the proper coolant/denatured water mix and good to go.

My personal feeling is the the "coolant flush" was the creation of auto garages 75 years ago as a money making opportunity to sell to the unaware public.

That's helpful, would it be "better" for me to bolt down the thermostat housing without the thermostat in place so the water can cycle easier, then install the new thermostat once I've drained the water out and am refilling with coolant?

 

[cruisermatt]

Hey Matt,

I appreciate your trying to help but this is my first project on this LC. It's also my first time getting into the cooling system on an engine at all. SO when you say "take a garden hose to the motor and radiator," I am assuming you're not literally telling me to hose down the motor and radiator... so that's what I am trying to clear up.

This guy is super annoying but just watch this

 

[dbla]

This guy is super annoying but just watch this

Haha okay that’s perfect.

Gotta assume total newb for me.

-a

 

[cruisermatt]

straight tap water and a half gallon of antifreeze will be fine until the weather starts to get cold.

 

[OSS]

just for a reference point after 30 years of doing it one way on my cruiser I'll add this info:

In 30 years and 295,000 miles I never once flushed out the cooling system on my 2F. Maybe 4 times in that 30 years I just drained it at the radiator and engine drain cock and filled it back up with 50% green coolant mixed with regular old hose water. I never used distilled water ever. I replaced the radiator once in 30 years.

I had the head off twice in thirty years and I could see down inside the head water jacket and inside the water jacket of the block and there was zero calcium buildup on the cast iron. There was some orange patina from rust but no chunky rust or flakey rust in the water jackets.

Seeing that my 30 year long endurance cooling system test revealed nothing unusual, I can safely recommend never flushing the cooling system (just drain it) and using regular ole tap water mixed with 50% green coolant.

 

[dbla]

just for a reference point after 30 years of doing it one way on my cruiser I'll add this info:

In 30 years and 295,000 miles I never once flushed out the cooling system on my 2F. Maybe 4 times in that 30 years I just drained it at the radiator and engine drain cock and filled it back up with 50% green coolant mixed with regular old hose water. I never used distilled water ever. I replaced the radiator once in 30 years.

I had the head off twice in thirty years and I could see down inside the head water jacket and inside the water jacket of the block and there was zero calcium buildup on the cast iron. There was some orange patina from rust but no chunky rust or flakey rust in the water jackets.

Seeing that my 30 year long endurance cooling system test revealed nothing unusual, I can safely recommend never flushing the cooling system (just drain it) and using regular ole tap water mixed with 50% green coolant.

Gotcha and that's good to hear... so just fill'er back up till she won't take anymore and get back on the road??

 

[cruisermatt]

Gotcha and that's good to hear... so just fill'er back up till she won't take anymore and get back on the road??

Yeah if your existing coolant/water looks clean then no need it flush it out.

 

[OSS]

well, these land cruiser engines can take a while to burp out all the air bubbles created when the block is drained- so I wouldn't just drain & fill & take off on a 1200 mile trip immediately after the radiator caps gets screwed on. Make sure the cooling system gets burped sufficiently after filling & keep an eye on the coolant level in the overflow tank for a week or so to make sure everything is stable

 

[Seth S]

just for a reference point after 30 years of doing it one way on my cruiser I'll add this info:

In 30 years and 295,000 miles I never once flushed out the cooling system on my 2F. Maybe 4 times in that 30 years I just drained it at the radiator and engine drain cock and filled it back up with 50% green coolant mixed with regular old hose water. I never used distilled water ever. I replaced the radiator once in 30 years.

I had the head off twice in thirty years and I could see down inside the head water jacket and inside the water jacket of the block and there was zero calcium buildup on the cast iron. There was some orange patina from rust but no chunky rust or flakey rust in the water jackets.

Seeing that my 30 year long endurance cooling system test revealed nothing unusual, I can safely recommend never flushing the cooling system (just drain it) and using regular ole tap water mixed with 50% green coolant.

TBH I have yet to use distilled water either . I often remind myself that this is an industrial fork truck engine thats survived 35 years without issue on nothing but basic maintenance. Heck it ran pretty well with all the valves .006" on the loose side

 

[LandoNick]

I just did this on My 60! After thermo, water pump, hoses to oil cooler and flushed heater core. flush was simple I undid the two hoses going to the heater core and flushed that forward and backwards. then flush the radiator while it was out doing the water pump. and the opener the engine coolant drain(lower driverside of engine block. then refilled with 50/50. found out I had a hole in my reservoir got a new on and a new cap with hoses.

 

[dbla]

Alright, guys... so its all assembled, gonna fill and whatnot tomorrow. However, in my messing with the thermostat housing, I broke two of the wires that attach to the lower driver side thermostat housing.

How can I go about repairing these, or do I need to order new parts??

The water temp sensor looks to be in pretty rough shape...

Also, am I good to fill and fire this puppy up with those sensors inoperable??

Thanks.

 

[Cruzerman]

Where I live, the tap water is very hard and loaded with minerals. It may not be necessary, but I use distilled water. At less than a dollar a gallon, I splurge.

 

[Prairie Swamp]

The green connector is the water temp input to the ECU. You need this to drive. The other one is the input to the temp gage in the dash you can get by without this.

 

[dbla]

The green connector is the water temp input to the ECU. You need this to drive. The other one is the input to the temp gage in the dash you can get by without this.

Can I get a new connector from auto zone and splice it onto the existing wire? Both the plug and sensor fell apart when I was trying to remove it.