What are your options when your temperature gauge hits red?


We all know that we need to check our car’s fluid levels regularly. This includes the obvious petrol top-up, plus oil, battery, brake and steering fluid, and radiator coolant.

If you need to supplement any of these, you need to find out why it was necessary. In the case of your vehicle’s radiator, regular topping-up means there is a leak somewhere, which could be external or internal.


Look underneath the vehicle for signs of dripping coolant. If you spot nothing, inspect the radiator hoses, connections, water pump and thermostat, as well as the entire radiator. Some leaks are very small, so carefully inspect the edges of the radiator for signs of discolouration, oxidation and seeping that is the same colour as your coolant.


This will be unsighted, so it’s best to head to a radiator specialist for a pressure test. A slow drop of pressure denotes a leak in the system. If the leak is not in the tanks or hoses, it could be a failing cylinder-head gasket. This may also show up through water in the engine oil or oil in the water. Another giveaway is white/yellow oil-water emulsion under the oil-filler cap, although this could merely be condensation under the rocker cover.


The majority of leaks are round the radiator. Whereas the older material of choice for this part was brass, modern units are made from lighter and cheaper aluminium, or a combination of aluminium cores and plastic tanks. These are repairable, but it is safer to fit a replacement when they start to leak.

If you are stuck out of town or need to conduct a quick fix to tide you over until you can afford a permanent repair, you could try one of the remedies mentioned below, but we would suggest buying a product from your local parts store. In previous decades, there used to be a number of products on the shelves (including Indian Head, now owned by Loctite), Bar’s Leaks and many others, but these days the choice is limited to just a few.

On that note, I recently performed a temporary fix of the radiator from a six-cylinder Mercedes-Benz engine with Wynn’s Radiator Stop Leak. This bottle has a three-year shelf life, so I would suggest buying one and stashing it away in your car for emergency use. The Musso 320 in which the engine was installed was losing a litre of coolant a week and I feared a blown cylinder-head gasket, which the owner would not have been able to repair due to the cost involved versus the limited value of the car. So I poured in the Wynn’s, put the heater on and ran the engine for a few minutes. After a week, I checked the car again and the leak had reduced by a substantial amount. Temporary job done. The next task is to remove the radiator and have it properly tested and repaired, but that is a story for another day.

Some history

Having mentioned the Cape Hell drivers, we searched through our archives and found this 1973 photograph of Jack Holloway overtaking Roy Laker on the inside at the Goodwood oval circuit. Another top driver was Wouter Smit, who admitted to having to replace six radiators in just one season. He then decided to relocate the cooling system to the rear of his Ford Falcon. The cost per radiator was R60 in 1973 which is equivalent to around R3 000 today.

Way back when the legendary Hell Drivers were racing at Cape Town’s Goodwood Showgrounds, I remember walking round the pit area between races and seeing
drivers like Jack Holloway and Deon de Waal making quick repairs to their V8 Fords and Chevs alongside their mechanics.

Due to the nature of the argy-bargy dicing, damage was aplenty and this often resulted in holed radiators. I was shocked to witness water gushing out of a number of holes in one car’s radiator, but a mechanic merely cracked open a tin (or two) of Indian Head radiator sealer, poured it into the radiator, added more water to replace the river flowing underneath, kept the engine running and, to my surprise, after a short while the leaks stopped. Good for another race. But, of course, this was a quick and temporary fix.

This brings us to a question: what does turmeric, pepper, eggs, chewing gum, baking soda and superglue have in common? They have all been used to provide temporary fixes for leaking radiators. Some swear these kitchen remedies work and, should you wish to experiment, go ahead … we would rather part with R100 or so for something a touch more scientific.

Author: Peter Palm

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