flushing cooling system

[roddy Junior Member Find all posts View Profile Close roddy]

hi all.
Am doing a major service on the prado and since this will be my first cooling system flush on this particular car, just wondering if there are any tricks i should be aware of.
eg, is there a drain valve on the engine block, I'm thinking there will be, so prior to searching eveywhere, if someone could point me in the right direction, would be greatly appreciated. Perhaps someone has done this job or has a workshop manual and could check for me..
cheers, Rod

ps i used the search but come up nil

[Zapper Member Find all posts View Profile Close Zapper]

On the 2004 model there is a drain tap on the bottom right of the radiator. I just drained and refilled.I made sure I ran the engine for 15minutes to let out any air from the radiator and then put back the cap and no problems.
I didn't remove any of the hoses so I will be also interested if anyone does it differently.

[roddy Junior Member Find all posts View Profile Close roddy]

hi,
yes i know of that one. Nearly all radiators have a drain tap... but that only drains the radiator, not the engine block. most cars have a engine block drain as well. The old way was to remove the thermostat, then flush out the block etc...
but, as eg, the RAV4 there is no need as there is a simple drain on the block adj the outlet hose so once the radiator is drained, you can then drain the block. Then close both drains, refill, then drain again. This flushes the whole system without the need to remove theromstat housing and theromstat or any hoses...
I'm hoping the Prado has the same, but before going searching, i was hoping someone who has done the job can let me know.
cheers, Rod

[clifton Advanced Member Find all posts View Profile Close clifton]

Hi Roddy,
Please advise Year/ Model, Engine Type and I will help :!:

[roddy Junior Member Find all posts View Profile Close roddy]

hi,
it is a 2005, petrol... 1GRFE
cheers

[clifton Advanced Member Find all posts View Profile Close clifton]

Hi Roddy,
I have sent a PM

[roddy Junior Member Find all posts View Profile Close roddy]

thanks, PM back at you...
cheers,Rod


I have sent a PM[/quote]

[Zapper Member Find all posts View Profile Close Zapper]

Hey roddy,you are right.I had a look at the workshop manual that I have just purchased and it shows two drain plugs one under each exhaust manifold and the right procedure to bleed the cooling system.
Looks like I have to do the cooling system again and to think I was told to do it that way by a motor mechanic. :evil:

[roddy Junior Member Find all posts View Profile Close roddy]

hi,
i know the way you did is quite common but i don't think it is really the proper way - more of a short cut for some mechanics...
It takes quite a few times of draining, running the car, letting it cool etc, etc to actually flush the system... the only problem then is, when it comes time to re-fill with proper coolant, you haven't drained out the block properly, so the block is still full with fresh water and the only coolant 50/50 ratio is in the radiator... thats why the old way of taking out the thermostat, then flushing and then draining the system completely, was a pain of a way to do it, but worked well.
I did mine today. I found the best way to access the block drains is from under the front gaurds behind the wheels - i took the wheels off to make it easier. The one on the O/S is easy enough to get to, but the one on the N/S is a bit of a pain.. It requires a 10mm socket on extention bar for both but the N/S also required a swivel socket as it is at a bit of an angle, i did not worry about attaching a hose to the drains, just droppoed it into my oil catch pan..
I drained it, through the block drains and the radiator drain, shut off all 3 and refilled with freash water and drained again - then filled with toyota coolant...
cheers, Rod

Hey roddy,you are right.I had a look at the workshop manual that I have just purchased and it shows two drain plugs one under each exhaust manifold and the right procedure to bleed the cooling system.
Looks like I have to do the cooling system again and to think I was told to do it that way by a motor mechanic. :evil:

[Zapper Member Find all posts View Profile Close Zapper]

Hi Roddy

I was on the understanding that when you replace the cooling you must keep the cap off to allow the air to escape but in the manual it says fill the radiator and overflow container replace cap and with heater ON start the engine and so on....What was your procedure when you turned off all three taps?Did you leave the cap off and filled as the level drop or did you have the cap on and filled via the overflow or stop engine let it cool and check radiator level? I know I should just follow what the manual says but I interested on how you did it?

thanks

[roddy Junior Member Find all posts View Profile Close roddy]

hi,
1.Cap off and opened all 3 drains, drained out coolant.
2.removed overflow tank, emptied and washed out clean, left off.
3.closed 3 taps, filled with clean water till radiator full.
4.opened 3 taps and drained again - no need to start engine.
5.repeated again.
6.Then when all the water coming out of the 3 taps was clear, no sign of pink coolant. closed the 3 taps and filled with Toyota coolant until radiator full.
7.with cap off, start engine, let it warm up and the level in the radiator did drop a little, topped up radiator as required.
8.once the top raditaor hose was gettting hot, put radiator cap on.
9.Then refitted the coolant overflow tank, hooked up the hoses and filled the tank to the full mark with coolant.
10.Let engine run for about another 5 min.
11.Shut engine down and allow to cool.
12.Once cooled down, check the level in the overflow tank and top up as required...
12. check again after you have driven the car next time..
ps, as for the heater on, not required these days as modern cars don't use the old on/off valve in the heater hoses anymore. Hot water runs through the heater system all the time, when you want heat the flaps move to allow warm air to pass through - but if it makes you feel better - set heater on.
Hope this helps, any other Q's, let me know.
cheers, Rod

Hi Roddy

I was on the understanding that when you replace the cooling you must keep the cap off to allow the air to escape but in the manual it says fill the radiator and overflow container replace cap and with heater ON start the engine and so on....What was your procedure when you turned off all three taps?Did you leave the cap off and filled as the level drop or did you have the cap on and filled via the overflow or stop engine let it cool and check radiator level? I know I should just follow what the manual says but I interested on how you did it?

thanks

[Zapper Member Find all posts View Profile Close Zapper]

Hey Rod I wonder if the service centres (or the stealers has they know in the States) would do a complete coolant flush or will they do just a radiator flush.
Anyway I will rather do it your way knowing that it is all flushed out rather than how I was told to do it. I am now close to the 60,000km service so I will do it again then.

thanks again

Zapper

[roddy Junior Member Find all posts View Profile Close roddy]

hey Zapper,
i have no idea but nothing would surprise me...
i have seen and heard plenty of bad things in the days when i was panel beating - always around cars etc... but that was a long time ago and am assuming there is more accountablility these days... In saying that, when ever i have had to take a car in for service, i have always marked the oil filter with a screw driver scratch and the sump plug with 'white out' to see whether it was really ever touched...
have a good one, cheers, Rod

quote="Zapper"]Hey Rod I wonder if the service centres (or the stealers has they know in the States) would do a complete coolant flush or will they do just a radiator flush.
Anyway I will rather do it your way knowing that it is all flushed out rather than how I was told to do it. I am now close to the 60,000km service so I will do it again then.

thanks again

Zapper[/quote]

[Guest Close Guest]

Does someone have a pic of the 2 taps on the block? I drained my radiator and a total 5L came out with the overflow bottle about 20% full. I ran the engine for a few minutes after the radiator drained and more came out. I put 5L of new coolant back in and this made the radiator AND the overflow bottle full to the brim.

The service manual says that there is 9.8L of coolant that should be running around. So as I have not done the procedure correctly (found this thread after I've done the work) I suspect that there is some air in the system and I've tried to get it out but the level in the overflow bottle has only dropped a bit.

So I'll be doing this again and need to know the locations of the other 2 taps. I also changed the top and bottom radiator hoses and had to use 2 sizes of multi-grips due to the space constraints and orientation of the clips.

[prado2004 Advanced Member Find all posts View Profile Close prado2004]

does anyone know where the drain plugs are on the block of a 1kz 2004 model manual trans? I am going to do this tomorrow and thought I would ask before I go searching forever! Are the 1kz's 12L of coolant as well?