Cleaning radiators...

[grifterkid]

First of all I apologise if this has been covered already...!!! Please do point me in the right direction if that is the case...

I have an old Triumph Toledo that, I suppose does need its radiator removing and cleaning out/flushing through. I can only imagine the crud and tat that's built up in there over the years restricting the flow of water and, ultimately affecting the performance of the radiator/cooling system.

Once I have removed the radiator what do you good people suggest for cleaning it out?! Should I soak/submerge it in a solution containing a household limescale cleaner (if so, overnight?!) or do I need to be a bit more professional/scientific about it?!

Please do let me know what your suggestions are as I'd like to give this a try and see if I can improve the cooling system of my trusty Coventry buzz-box...

Ta, muchly in advance...

[barty]

cheap and cheerful just run a hose through it and flush it through both ways.
If you use a high pressure or chemicals you may find leaks that you never knew were there before lol

[ChasR]

IMHO and experience a hose inside will get quite a bit out but the core will still ultimately be blocked. Some people use Sterident with sucess whilst others uncover and cause other issues along the way (putting something acidic into a cooling system has never appealed to me unles it offers some form of protection (against corrosion/furring up etc.

One proven solution is to take a tank off and rod the radiator. This however can cost near enough as much as a recon radiator would be.

I would be tempted to say flush it and see what happens but after seeing a flurry of cars around me almost (or actually overheat) in addition to having a similar experience with my Stag (OK, they have a reputation, but still...) it is always quite surprising the difference a combination of a fresh radiator with no silt within it along with fresh coolant can make.

FWIW, I had the same issues on two previous cars (Pug 306 and Stag). On both, changing the rad cured many issues and the Stag is now fine for hot days .

[grifterkid]

Hmmm, I like the steradent idea...!!! I don't imagine that Steradent is very harmful in terms of what potions it contains?!

I imagine I'd just fill a huge containter with fresh water and a handful of Steradent tablets and submerge the radiator in that solution for a day or two...?!

What do you lot reckon...?

[ChasR]

Give it a go, but be aware you may end up with more leaks. Another theory would say it was going to go either way. Regardless of the situation I would observe the temp gauge like a hawk afterwards (easier said than done mind you).

[Mystery Machine]

I have been using the steradent trick for many years. If going down this route, don't bother removing the radiator, but instead keep it in place and run as follows:

Drain all coolant out of the system and flush through both the engine and radiator (seperately) a number of times. If possible, flush, then backflush, then flush the radiator and engine through. A few times if you can.

Reconnect the whole system, moslty fill with water then drop in a whole tube of steradent tablets. Allow them to dissolve and top up the system as normal.

Run the engine, bleeding the system if your engine has bleed points, top the water up again then let the whole system come up to temperature (ideally wait until the thermostat is open and the radiator really hot)

The engine and radiator should now have a nicely mixed steradent solution all around it. Leave the whole thing for 24hrs to allow the steradent to do what it can to the coolant system then flush the lot out the same as you did initially.

Once you're happy you've flushed it all out, refill, bleed and top up with the proper coolant/antifreeze mix and see how you get on.


I did have a radiator that was so clogged that steradent wouldn't touch it. I removed the rad and filled it with neat brick acid (I bought this from Wickes) and left overnight. The very next day I emptied the radiator and couldn't believe the sludge & curse word that came out of it despite having done my usual flush with water then steradent. The brick acid had broken down and dislodged SO much build up from the cores that the radiator could now take double the coolant it had before!!

Here is the radiator where you can see the cores (just) completely clogged with limescale and years of silt build up. This was AFTER flushing through for 24hrs with limescale remover.


Here is the brick acid doing its thing. There was a definite fizzing throughout the process as the limescale gradually dissolved.



However, this also highlighted that the radiator was past its sell by date because not only did it remove most of the crud that was blocking the cores, but it also opened up holes in the rad that were previously being blocked by the sludge and limescale. Brick acid won't corrode the brass of the radiator itself, so wasn't resonsible for creating the leaks but as a byproduct of removing all the debris and limescale, also showed that the radiator was beyond its best.

I ended up having the radiator recored and the difference was immense! I could see how much debris was still in the old cores despite the sterdaent THEN brick acid flush..and despite seeing how much crud came out of the radiator.

Basically, if your radiator is old enough and clogged enough to need flushing, the chances are it's possibly going to need replacing, but give it a go with some treatments first because it might just be good enough to revive without ending up with a sieve.

Here's a video of some of the sediment that came out of the radiator after leaving brick acid in it overnight (most of the horrible sludge had already been poured out before I thought to video it)


Here is what I was greeted with once the newly flushed out radiator was refitted. This led to paying for a recore...which was less than ideal, but such an improvement that I'm glad I did now.

[taurus]

I remember a similar thread a while back retrorides.proboards.com/thread/146832/clean-out-radiator-acid

[phil73]

I suppose any old acid would work e.g. acetic acid (vinegar does a good job on limescale around the home), cheap and relatively safe. You could then neutralise it with an akaline solution of some sort of you were worried e.g. baking soda.