Audi b5 diesel cooling system cleaning

[MattE]

I have a 1.9tdi b5 audi, changed the cam belt, water pump and all other bits involved yesterday. The cooling system was full of rust and a type of brown lime scale. Would it be safe to use a strong caustic solution to clean it out?

[usedabused]

I always run the engine with a dose of calgon and flush with a hosepipe do the engine separate to rad and run until the water runs clear,


If you have brown sludge its probably had the wrong antifreeze added at some time.

And be careful with the hoses that pass threw into the bulkhead and the heater matrix can very easily be damaged.

[composimmonite]

Cheap bleach is a manufacturers method of cleaning out cooling system after head gasket failure and oil contaminated waterways.
By accident I once topped up my cooling system (in Renault Savanna) with TFR (truck wash / Traffic Film Remover) and that did an amazing job of cleaning.
Another time I used wine makers citric acid to clean a system of limescale that had almost blocked a rad.

Paul H

[usedabused]

Bought a Polo sdi with severe oil/water mix so I flushed it with Autosmart Ali, ( basically hydrofluoric acid ) did an amazing job of the cooling system but turned the rad into a sive.

[dodgerover]

May 17, 2014 15:03:10 GMT usedabused said:

Bought a Polo sdi with severe oil/water mix so I flushed it with Autosmart Ali, ( basically hydrofluoric acid ) did an amazing job of the cooling system but turned the rad into a sive.

I hope it wasn't hydrofluoric acid thats really really nasty stuff and eats through just about anything including glass and metals. I wouldn't put it anywhere near anything I didn't want destroying even if very dilute. Its also a contact poison, look up hydrofluoric acid burns - it doesn't feel like its burning initially so you aren't going to be aware it happened until things start going wrong.

[composimmonite]

May 17, 2014 20:08:28 GMT dodgerover said:

May 17, 2014 15:03:10 GMT usedabused said:

Bought a Polo sdi with severe oil/water mix so I flushed it with Autosmart Ali, ( basically hydrofluoric acid ) did an amazing job of the cooling system but turned the rad into a sive.

I hope it wasn't hydrofluoric acid thats really really nasty stuff and eats through just about anything including glass and metals. I wouldn't put it anywhere near anything I didn't want destroying even if very dilute. Its also a contact poison, look up hydrofluoric acid burns - it doesn't feel like its burning initially so you aren't going to be aware it happened until things start going wrong.

Is that the stuff which they have to amputate limbs to stop it killing you ?
Mate was Police officer and they were told not to touch burn out cars as there was something nasty produced that did the above

Paul H

[dodgerover]

Irrigate immediately then hospitalisation with an IV of the correct stuff to try and neutralise what its doing in your body might be the correct way of dealing with it, however its been years since I had to look at safety data sheets, the main danger was not realising you had been exposed to it at the time hence delaying treatment.

Potential for all sorts of nasty substances to be present in a burn out or after a fire of any kind of unknown combination of waste materials really.

[usedabused]

May 17, 2014 20:54:48 GMT composimmonite said:

May 17, 2014 20:08:28 GMT dodgerover said:

I hope it wasn't hydrofluoric acid thats really really nasty stuff and eats through just about anything including glass and metals. I wouldn't put it anywhere near anything I didn't want destroying even if very dilute. Its also a contact poison, look up hydrofluoric acid burns - it doesn't feel like its burning initially so you aren't going to be aware it happened until things start going wrong.

Is that the stuff which they have to amputate limbs to stop it killing you ?
Mate was Police officer and they were told not to touch burn out cars as there was something nasty produced that did the above

Paul H

This stuff is really dangerous however your describing saturation over 60% Hydrogen Fluoride this stuff about 5-6% saturation.

I used 60% plus when in the glass industry for removing unwanted ceramic inks from toughened glass.

Safety Data sheet.

www.autosmart.co.uk/images/PDF%20Folder/Autosmart%20COSHH%20sheets/ALI%20-%20SDS10015%20-%20GBR.pdf

[joe90]

I have my Audi to do and was told to use central heating flush, I haven't ried it yet though.

Bryan

[MattE]

May 18, 2014 10:21:55 GMT joe90 said:

I have my Audi to do and was told to use central heating flush, I haven't ried it yet though.

Bryan

Central heating flush the way to go, heater blowing red hot expansion tank de-scaled all hoses soft and clear. Thanks for the tip.

[usedabused]

Any progress on this

[MattE]

Job done, central heating flush got the system as clean as new, very impressed. Thanks joe90

[usedabused]

Good tip that nice one.