Topping Up Coolant - it's all water at the moment

[paulmorgan]

Had a major coolant loss event today... driving along the M4 suddenly noticed 'that' smell and a load of steam escaping from the left hand side. Pulled over onto the shoulder, popped the bonnet, expansion tank cap sat on top of the leisure battery and coolant all over the place. I'd visually checked the level before I set off and the cap was on. Can only assume that it wasn't on properly and had twisted off under pressure - it wasn't damaged in any way.

AA called - taken to the services and the mechanic arrived. Between us, my ipad and the bwitched blingo youtube video we did a pretty good first time job of filling and bleeding the system. Pressure seemed good, no combustion gasses. 40 miles back home and it all seems OK. Lucky boy (I think).

Anyhow - there's pretty much no antifreeze in the system now and I need to get a load in there. I'd rather not go through all of that again - is there a way to gradually drain liquid and add antifreeze without needing to re-bleed?

[dreamwarrioruk]

the problems occur if the water level drops below the cylinder head, suppose you could fill it through the bleed pipe provided you dont add any air in there and simultaneously drop it out of the radiator. whatever you do its gonna be worth doing the bleed again to be sure.

[Simon Jones]

Sounds like you had a lucky escape. Worth getting a low coolant alarm as you may not notice steam if you get a leak underneath or when it's raining.

Personally, I would undo the drain plug at the bottom right corner of the radiator, drain out as much as possible and then refill with 5 litres of fresh antifreeze and then fill the rest with water. If you are not sure when coolant was last changed, or what type it is, then consider flushing the system out fully first. Then you can rebleed it again, but under more controlled circumstances.

I don't think there's any point trying to drain small amount out while putting same amount back in again. All you will end up with is a really weak mixture which is not going to give you the protection against frost or prevent corrosion in the system.

[Ahead]

I had the same issue a few weeks ago. I have a low coolant alarm but it didn't go off, the Mason alarm saved me fortunately. Coolant was bubbling out of the header tank and I guess that's the reason the LCA didn't sound. Like you I was lucky the cap hadn't fallen out of the Bongo completely.

I would drain some coolant out, add antifreeze and re-bleed. It's a bit of a pain but at least you'll know there's no air trapped. At least the second time you won't be under as much pressure, take your time and all will be well.

[scanner]

I did a coolant change quite a while ago now by the following method but you only need the second bit as you've already done the first bit.

Remove pressure cap on header tank and then take out bleed hose, suspend it securely up as high as possible and fit funnel into end of it.

Pour fresh water into funnel until clear water comes out of header tank. Refit pressure cap and run engine for a short while but long enough to stir up the coolant in the system.

Remove pressure cap again and continue to flush system through with clean water until really clean water runs out of header tank.


<You need to do from here......>
Get can of "Forte Coolant System Flush" from local stockist and add to system via bleed tube.

http://www.forteuk.co.uk/product.php?id ... stem_Flush

Refit bung to bleed tube and refit it back in engine bay.
Syphon out enough water from header tank to reach "MAX" line.

Run engine in accordance with "Forte" instructions to circulate flush around engine.

Follow step one again to get clear water through whole system.

Then add 50/50 solution of coolant until coloured coolant runs out of header tank and then to be safe I added a litre of neat antifreeze to the system to make sure strength was high enough.

Replace bung in bleed pipe, refit bleed pipe in engine compartment, syphon off coolant from header tank down to "MAX".


If you have ensured the funnel and bleed pipe have been higher than the top of the engine throughout the procedure you SHOULD have avoided any air getting into the system - my Bongo has run for over a year now without any problems (so far ).

I don't claim that it's an approved method or guarantee you won't have any problems if you try it - but it seems to have worked for me and saved having to go through the whole bleed procedure.

I think from memory that I ran the Bongo for a couple of days (50 or so miles) with the Flush in the system and didn't notice any LCA bleeping or temp fluctuations (my gauge is modified to react quickly to changes) in that time - nor since.

Judging by what came out in the flush after using the Forte it certainly seems to do what it says in the advert.

[peterrc]

I did a similar system to the one used by scanner but in reverse.
Take the cap off the header tank, Remove the bleed tube keeping it up and slowly drain water until it is low in the heater tank. Put neat antifreeze into the header tank and continue the above operations until you have added enough neat antifreeze to give you the mixture that you require. Lower the coolant to the correct mark on the header tank and replace bleed pipe and bung. Run the engine until the thermostat opens and allows the neat mixture to mix.

[scanner]

I did a similar system to the one used by scanner but in reverse.
Take the cap off the header tank, Remove the bleed tube keeping it up and slowly drain water until it is low in the heater tank. Put neat antifreeze into the header tank and continue the above operations until you have added enough neat antifreeze to give you the mixture that you require. Lower the coolant to the correct mark on the header tank and replace bleed pipe and bung. Run the engine until the thermostat opens and allows the neat mixture to mix.

Probably a less messy way of doing it. I only did it the other way to be sure of not letting air into the head. If water is going into the funnel at the top of a raised bleed hose and out of the header tank the water level has to be higher than the head at all times.

[paulmorgan]

Thanks for all your help on this. The cold snap came before I could do anything fancy so I just drained out a just over a couple of litres from the radiator drain tap and stuck a couple of litres of blue antifreeze into the radiator and then topped up the header tank with the coolant I had drained. (I used basic comma blue blue to match the colour of what I already had in there)... ran it for a bit and then drained out another litre and added a further litre of coolant into the tank and mixed again over a short drive. Think the strength should be OK.

I've since followed the procedure for bleeding the system again and not got any more air out. Found that I get the funnel quite full even when it's up as high as it will go if the expansion tank is up to the full line so I had to let about a litre out of the system from the bleed tube so it was manageable to see-saw and get the bung back in etc. Use of mole-grips to clamp the hose before refitting the bung is my top-tip. And also it's really a two person job - I struggled on my own.

A full flush, drain and fill with Comma Red is for another day.

[Simon Jones]

I think you timed it just right before the frost really sets in. My tip would be to get one of these pipe clamps by Laser: http://www.halfords.com/webapp/wcs/stor ... yId_255216

As they have plastic jaws they are less likely to damage the bleed pipe that any other metal clamps with serrated teeth. They come in two sizes, but the smaller one is ideal and will fit rubber brake pipes too if you ever need to remove a caliper.

[mantaJim]

Sorry to hijack this thread but I've just received the bottle of Forte coolant flush I ordered on line and see it suggests that it should be added at 8% of cooling system capacity in "larger" vehicles. The bottle is only 400ml whereas the cooling system volume on the Bongo is 13.5 litres I believe which would imply I would need 2.5 bottles of Forte.

My van is a V6 with rear heater removed so not sure how much if any this changes capacities (minimal reduction I would guess?).

The van had blue/green antifreeze up until a week ago but has plain water since. I'd like to replace with the Carplan red premium as this seems to be the one favoured by many on BF but wary of cross contamination.

<You need to do from here......>
Get can of "Forte Coolant System Flush" from local stockist and add to system via bleed tube

Scanner did you use a 400ml bottle (the one in your link) and if so did you find this was enough - as I'm swapping to the Carplan red I need to ensure there is no contamination between the two coolants. I could be wrong but if I understand correctly the red stuff adds a protective coating whereas the blue stuff doesn't. On this basis I assume there is less of a risk of residual blue coolant provided I flush with Forte and then clean water than say if I was replacing the red with blue - so I'm tempted to go with the one bottle of Forte - is this a reasonable assumption ?

Cheers

Jim