MG-Cars.net

Welcome to our resource for MG Car Information.

Recommendations

Parts

MG parts spares and accessories are available for MG T Series (TA, MG TB, MG TC, MG TD, MG TF), Magnette, MGA, Twin cam, MGB, MGBGT, MGC, MGC GT, MG Midget, Sprite and other MG models from British car spares company LBCarCo.

MG Midget and Sprite Technical - Flushing/cleaning the cooling system

I am currently sorting out the cooling system and now that I have got the thermostat housing off (thanks guys!) it is clear that the PO has used some sort of goop to cure leaks - Radweld etc.

Whats best to clean out the system - I was thinking of dropping a dishwasher tablet in and running it for an hour then flushing it out with clean water several times before refilling it with 50/50 water/antifreeze.

Any thoughts??
David Banks

if your radiator (and heater core) have portions clogged with that stuff, you will probably have to take them to a radiator specialist to be either "rodded" (they remove the end tanks and run a wire down each "tube" to clear it out, then solder the end tanks back on), or re-cored (same as above, but replacing the core completely). There might be some kind of solvent that will dissolve the "stop leak", but getting it to work in those tiny, capillary-like passages in a radiator without mechanical cleaning is never certain. Also, if that stuff was used, maybe the radiator has a leak somewhere in the first place. The radiator specialist will repair that while they do this, too.

One quick way to tell if part of your radiator is clogged is to run the engine up to temperature and then (engine off so you don't hit the fan), feel every inch of the radiator. Cool portions = clogged. A thermal sensor is more accurate than your hand. Access to the front of the radiator is best of all (difficult with a midget), so you can have the engine running and the airflow over the surface keeping the clogged areas cool and the circulating coolant keeping the non-clogged areas warm/hot, so you can tell the difference.

Vinegar works well to dissolve minerals (the result of DPO using tap water), and automatic dishwasher soap works well (at high temperatures) to clean other stuff, and doesn't foam. In either case, like you suggested, run the engine for a while to get the cleaning action.

I had a radiator that felt strangely heavy when I removed it, the radiator shop showed me that it was almost 1/2 full of stop leak (!). The car had run "OK" like this since I had bought it (nicely, radiators do have some design margin, usually, though your actual mileage may vary).


Norm
Norm Kerr

This thread was discussed on 17/01/2010

MG Midget and Sprite Technical index

This thread is from the archive. The Live MG Midget and Sprite Technical BBS is active now.