Corner Wrench: How to clean the outside of the radiator

No, we’re not talking about any dirt or build-up inside the radiator, but instead the outside.

Living, working and driving in Canada often means travelling on unpaved roads with more than the odd jaunt down some narrow wooded lanes. Hardy drivers in these regions are quite used to taking some extra care and cleaning to keep their rides looking their best, or at the least, not too objectionable to be seen in.

And, while drivers can get adept and effective at removing road grit and grime in the hardest to reach areas, one region, right up front, often gets little attention until something goes wrong or, in certain cases, hot.

Radiators and air conditioning condensers are unique pieces of automotive equipment. They are fairly fragile and susceptible to impact damage, yet, because of their function, are placed in the line of fire, right behind a grille that offers some styling but little protection.

Radiator and condenser fins are great traps for grit, small stones, leaves and fibres. You name it and it can get caught. Collect enough and it’s easy to reduce the air-flow through these units, driving engine and refrigerant gas temperatures up.

But things don’t have to be severely clogged to see problems rise.

If enough of a collection of small stones get trapped in a radiator’s fins, they can alter the heat exchange performance of the unit to the point where the engine overheats.

Checking for build-ups is a fairly easy visual exercise, but any cleanup required takes a no-pressure approach.

On older rads and condensers, it takes very little contact pressure to fold the fins or even cause a leak in one of the core tubes (new ones aren’t much stronger).

The water flow from an open end of a garden hose directed forward from the engine side through the fins should safely dislodge most debris.

Removing the upper plastic shield over the rad (if there is one) can give you a better view of what’s being flushed through and what may need more gentle persuasion. Most pressure washers, including small anemic domestic units can easily damage a healthy radiator and blast through some war-weary ones.

Leave any scrub brushing out of the equation. If normal tap pressure doesn’t dislodge it, you may need to tackle stubborn bits up close with a toothpick.

Think twice about installing a piece of window screen in front of the rad to collect debris and bugs for an easier clean-up. The small holes on these can block very easily and quickly under the right conditions, bringing things to a boil.