flushing radiator coolant

[Robotnik123]

There doesn't seem to be a guide on how to flush radiator coolant. CVR4 is a bit sketchy on this too. Any chance someone could explain it for a simpleton like me, please? There appears to be a bleed screw and drain plug I need to access.

 

[Guest]

the drain plug is at the bottom of the radiator in left or right corner.. the bleed screw would be near the water pump im guessing.. follow the top radiator hose and you should find it..
hope this helps.

 

[SiliconAngel]

Jan DO NOT use the bleed screw or drain plug - they have a NASTY habit of becoming brittle and snapping off.

1) Make sure your vehicle is parked on a flat surface.

2) Place large catch pan(s) below radiator. You'll be disconnecting the bottom hose so coolant will come out of the hose and try to flow forward, and out of the radiator and try to flow backward, so try to use something that will catch the coolant as it escapes in both directions.

3) Remove radiator cap.

4) Undo / remove the clip holding the bottom (return) hose onto the radiator.

5) Disconnect the bottom hose from the radiator, taking care to direct it towards your catch can. Lots of coolant will come gushing out, so do your best not to lie underneath while doing this.

Note: If you have difficulty removing the hose 'cause it seems to have seized onto your radiator you can use something like a butter knife to slide up into the end of the hose to break the seal that has formed over time, and then twist the hose back and forth on the mounting tube. Be careful though - if you twist the hose too much and it's a little old or very securely attached you may damage it internally and after a few 1000kms it will split (ruining your day). I only ever do this with hoses I'm intending to replace anyway (I'm a bit OCD about replacing hoses).

6) Refit is the reversal of removal.

If its your first service, use a cheap coolant or just demineralised water and a coolant flush to give everything a good clean. Instructions can be found on the bottle.

 

[Robotnik123]

Yeah thanks for the tips! Will drain her this weekend. The coolant is looking decidedly light green, not the glowing emerald colour it was last year, so probably near time for it.

 

[Guest]

thats the way i do it but you asked where the bleed screw was and the plug was.lol

 

[SiliconAngel]

Its a fair enough assumption to use the bleed system they clearly designed for this purpose - its not our fault they make them of nasty cheap plastic that gets brittle and shatters

 

[Robotnik123]

Its a fair enough assumption to use the bleed system they clearly designed for this purpose - its not our fault they make them of nasty cheap plastic that gets brittle and shatters

But wait, what about filling the coolant back up - if you don't use the bleed screw how can you make sure you don't get an air lock?

 

[Guest]

what i do is when i put the coolant in i squeeze the lower rad hose, when you squeez the hoses it releses the air, do it a few times. just like bleeding brakes, keep squeezing untill the air comes out but dont let the coolant level drop to much as you will get air in it again..
after a run you should check the levels again anyway and watch your temp..

 

[SiliconAngel]

Like Joe said, squeeze your hoses periodically as you refill. Once you think you've got it full, run the car at fast idle for 10 mins or so to open the thermostat. Let the car cool then top the radiator up. Check it again the following day, but I bet it's 99% full.

 

[Guest]

thanks trev im bad at explaining things.

 

[gilly]

how many litres does it take to fill it up completely?
ie to fill the radiator and the system after draining it all.

 

[Outlanded]

how many litres does it take to fill it up completely?
ie to fill the radiator and the system after draining it all.

from memory I used about 7-8 litres complete flush, that including filling the coolant container.

 

[SiliconAngel]

that including filling the coolant container.

Overflow tank?

 

[Guest]

that sounds bout right.. should be 6 or 7lts

 

[IntenseVR4]

What is the best way to drain coolant from the block?

With both radiator hoses joining the engine high up it would leave alot of old coolant in the block if you were to just remove the lower radiator hose.

The way to do it with the ol' VL Turbo was to undo the coolant feed for the turbo. I'm guessing its the same. Didn't have time to remove the plastic cover thingo to check it all out tonight, but if someone knows the correct way post it up!

Sorry for bumping an old thread but i figure all the info for a drain/flush/refil should be in the same place.

 

[Guest]

In addition to what Trev said disconect both radatior hoses and run water in the top hose and in the bottom hose. This will dislodge any build up that has formed in the block. try to flush out both ways 3 or 4 times first the top hose then let it all drain out then the bottom hose and let it drain out. Do this untill the water runs clear and the smell has gone from the water. You will understand as soon as the first hose has come off.

 

[Mac Dog]

My mate who is a mechanic helped me flush the system with a little ingenuis tool that uses gravity to flush the system out.

I'll have to create diagram to explain it. But yes, flushes the system out totally and is fairly quick and not so tedious like all the other methods used.

I seriously can't believe I never thought of it.

 

[SiliconAngel]

If you want to flush the block completely you'll have to bypass the thermostat, which is easy enough really. After flushing my cooling system no less than FIVE TIMES, when I replaced my thermostat and water pump I found a lot of crusted up flakey gunk hiding inside. I've got a photo on one of my PCs that I need to upload sometime...

 

[VR4 MAD]

Stuart (IntenseVR4) PM'ed me quite awhile back now, asking what was shown in the new 'workshop manual' for a full drain of the engine block.

So here it is then. This is what the dealer garages should do if this task is needed.

Hope that helps everyone.

 

[Guest]

What is the "Herme seal H-1m" dry seal agent that is described in the above procedure, and do we need this? I'm assuming it's some kind of sealant to put on the drain screw threads and that silicone would suffice.