What is the best method for a Safari coolant change/flush

[Ant]

Road trip this weekend and wanting to replace the coolant.

Last time i did it I only managed to get about 5 liters of water/coolant into it so was obviously only doing a half ass job. My manual says to drain it, fill it, drain it, fill it, drain it, fill it slowly to prevent air blocks. T

then i heard about other methods of removing the thermostat and sticking the garden hose in somewhere and blasting it while the engine is running for 5-10mins. I like the sound of this as it sounds like it will give it a really good clean out. Its an old safari and im sure it hasn't been done properly to many times in its life.

Can I have your thoughts on this and any other info you have, maybe a bit more detail on where to put the garden hose and which hoses to pull off etc.

While im here is there any specific coolant to use that is better than others. I plan to be doing a flush quite regularly so dont care about the long life stuff. And should I be using a "Flush" treatment??? I have heard horror stories about some of them but seems like a good idea to clean it out. And last one...how do i aviod getting air blockages and how do i get rid of it if i do get one???

[3VILC]

Hi Ant,
There is a blanking plug under the exhaust manifold towards the rear of the block, this is the coolant drain for the block, tho I never had any luck getting it out as I pressume it probably locktited in there. I just take radiator out and turn upside down and give it a good reverse flush. I put the hose in both inlet and outlet of the block and run until clear, then put the bottom rad hose back on the block and run the engine for a short time with the garden hose in the bottom hose, make sure you've got plenty of flow so the water pump doesnt run dry. Works for me anyway, maybe not as effective if your coolant is very rusty tho.
As for trapped air, the safaris are a truck engine and usually have a breather at the highest point (the "thermostat housing" in this case, even tho the thermostat isnt in there but you know what I mean ), so air will naturally work its way out in theory, its only really an issue on engines like the RB's where the high point in the system is not the radiator cap, hence they have air bleed screws all over them.
Personally, I'm not a fan of those 'flushes' of any sort, they can tend to dislodge crud only to have it all clog up the radiator later, or oil flushes can wash away 'good' buildup inside the engine which is stopping seals etc leaking

[Crash bandicoot]

the best way is to drain as much antifreeze as possible then hook up the garden hose to one of the heater hoses and let it back flush out the radiator cap.

[slide]

Drain out old coolant and flush it down the toilet (no kidding, then it goes to sewers to be treated- don't let it go down stormwater drains).
Then with radiator bung loose, flush radiator both ways via radiator hoses and undo heater hose and flush (with tap in 'hot' position) until flows clear.
Flushing heater bypasses themostat, although if there's any doubt it can be a good time to remove thermostat to inspect/test.
Don't forget to flush overflow bottle.
When refilling fill the antifreeze in first, if the block hasn't been drained there's a good amount of water in there which would dilute your mix if you premixed the coolant.
Idle the engine with heater tap in hot position and radiator cap off until up to normal operating temp. Top up water level as required, fit cap and test drive.
After engine has cooled off recheck level, both under cap and in reservoir.
If using the same type coolant you don't need to be as thorough next time, but if its rusty or you don't know what type(they don't like to be mixed) or how long the coolants been in there its a good scheme to do it this way.

[Ant]

Thanks guys. Worked a treat. However, my hoses are shot, very very crunchy and the water was quite brown. Can't get new hoses before I go so will be cleaning them as much as possible then repeating the process again. .......ripco want $100 per hose... I have new top and bottom hoses on but need the heater hoses, any idea where to get these? And am I going to kill the truck running the crap heater hoses for a few more days?

[Trundle]

Dont flush it before the weekend if you dont want to remove the whole front cover etc ,
If the cooling system is shot and you go ad an inhibitor (antifreeze) it will come out of all the crusty gaskets that go through the whole front cover , etc , also if the water pump hasnt been replace i would strongly advise doing that before you add antifreeze ,another suggestion is to use genuine nissan thermostat only !!

[bang-thud-thump]

Thanks guys. Worked a treat. However, my hoses are shot, very very crunchy and the water was quite brown. Can't get new hoses before I go so will be cleaning them as much as possible then repeating the process again. .......ripco want $100 per hose... I have new top and bottom hoses on but need the heater hoses, any idea where to get these? And am I going to kill the truck running the crap heater hoses for a few more days?

Cheaper than a motor and crunchy hoses are the ones that fail as a rule.

And you will still need to buy hoses if it cooks.

[fish]

I'm not a fan of those 'flushes' of any sort, they can tend to dislodge crud only to have it all clog up the radiator later, or oil flushes can wash away 'good' buildup inside the engine which is stopping seals etc leaking

yup i put one in my jeep and it leaked oil and smoked for ages.

[DaveM]

I've always gone away from the Genuine Nissan thermostats in my Safari's to keep the temps down. Haven't had a problem as yet.