A question of degree

Everyone likes to put off paying for stuff. But while buying a bed at a ‘Don’t-pay-a-cent event’ might make a certain kind of sense, saving money by deferring maintenance on a car’s engine cooling system is a disaster in the making. Repairing or replacing a cooling system that broke down because it wasn’t maintained properly — not to mention the critical care for the other systems that got damaged as a result — can cost multiples of what timely maintenance would have.

Even if a negligent car owner beats the odds by avoiding a major catastrophe for a while (and it’ll still happen, sooner or later), it’ll cost in other ways, by degrading overall performance and generating a host of debilitating secondary problems — chronic overheating, for example — and more frequent replacement of components such as cylinder head gaskets, heater cores and radiators.

The much neglected radiator

Radiators weren’t always as important in the service mix as they are now. In the past, a car’s useful service life and the reasonable lifespan of a radiator used to be about the same. Now, cars are being driven well beyond the typical radiator’s service life. It all means that serious shops now have to take a look at radiators as a bigger part of the service package.

Talk radiators for more than five minutes with a shop owner and technician and the odds are you’ll be talking about the coolants and other mixtures that are put into them. While radiators have changed over the years, the evolution has been pretty logical: they’ve become lighter and smaller, with tighter cooling tubes and more cooling fins packed in. Coolant, on the other hand, has evolved about as far beyond its honey- or molasses-based forebears as we have beyond the platypus.

In addition to at least a dozen different colours — which sometimes mean something and sometimes don’t — there is a range of chemical profiles designed to provide extended coverage, specialized capabilities for different climates and driving profiles, and to minimize the toxicity and environmental damage done when spent coolant is released or improperly disposed of. There’s a veritable chemical laboratory inside the modern automotive cooling system, and this makes it a lot harder for do-it-yourselfers as well as the pros to keep everything in fighting trim.

Radiator Specialty Co. of Canada Ltd., based in Mississauga, Ont., is a full-line additive manufacturer that has been in operation for 75 years, eight years less than its U.S. parent. The company’s first product was a radiator stopleak, a high-demand item in days when large, ungainly radiators protruded from the front end of vehicles traveling over unpaved roads.

“Now you can’t even tell where the radiator is,” laughs Richard Navin, the company’s national sales manager. He says that age and the stress that comes with longer operating service is tough on radiators. But he also knows that some customers will use coolants incorrectly. “Vehicles require a specific coolant type, and that’s for a reason. You can’t just plug in the lowest-priced product on the market. If you do, ultimately you pay a price.”

Correct procedure is still critical. “If you have a system with corrosion, grime, suspended solids and so on, there’s potential that you could wind up plugging a small passage if you don’t flush the system before putting in a stopleak,” says Navin. Radiator Specialty also makes a non-acidic flush. If acidic flush is not properly neutralized it can wind up corroding copper, aluminum and brass components.

So what is the number one rule a technician has to remember when it comes to coolant? Obvious as it may seem, but which sometime needs to be repeated, is never pour the stuff into the radiator in pure form. Pure coolant has poorer antifreeze and anti-boilover properties, which of course sounds counterintuitive. Pure ethylene glycol actually has 25 per cent less heat capacity than pure water.

Coolant must always be mixed with deionized or demineralized water. The usual proportion is 50:50, although you can find a mix as high as 70 per cent coolant recommended for colder climates. Use tap water and you introduce chloride and chlorine. Chloride corrodes metals, especially aluminum, while the chlorine forms additional chlorides.

Always remember to look at hoses

“The hose is a bursting point in the cooling system,” says Marc Therrien, account executive, replacement products with Goodyear Canada Inc. in Toronto. “Once it goes, your cooling system is down and you’re stranded on the side of the road.” The constant transition from severe cold to engine operating temperatures, and then back again, will inevitably degrade hoses.

To make matters worse, electrochemical degradation occurs on the inside surfaces and works its way out, a factor that compounds the confusion when servicing the system. The most important customer education guideline Therrien and others say service technicians can offer, is to make the driver aware that a hose that looks okay can actually be close to bursting point. Technicians should also keep that in mind and check for softness at attachment points, as well as signs of bulging. New compounds, such as the ‘striation-resistant’ product offered by Goodyear, is manufactured with an inner surface that resists the electrochemical processes.

Newer radiator hoses are custom shaped to fit around engine components without stress to the hose or clamps. It makes for a better fit, but if you don’t have dozens or hundreds of SKUs on hand all the time, replacement is a time-consuming process. Goodyear’s E-Z Coil system is one response that Goodyear said is likely to see more market uptake. It involves fitting a set of metal coils over standard hose. The coils containing the hose are then bent to the required configuration, which they maintain while preventing hose kinks that restrict coolant flow.

Water pumps prey to problems

The water pump is prey to many of the same problems that radiators face: clogging, corrosion and leaks. It’s also a prime spot for air to be introduced into the system through defective or corroded hose attachments, through which coolant can leak. Rust from iron cylinder blocks is very abrasive and when it becomes suspended in the coolant it wears down the pump seals. An eroded pump seal can create a suction leak that introduces air into the coolant, degrading the system’s performance and creating blockages.

To top it off, water pumps house moving parts that require proper lubrication to work effectively. “The water pump lubricant should be changed out every three or four winters, about the same as the antifreeze,” says Navin. But he notes that as new longer-service coolants come onto the market, the water pump will become a higher-profile service item. This is especially true when you consider that modern radiators have narrower cooling tubes, run hotter and are subject to the effects of mismatched or improperly mixed coolant.

At the end of the day, the best wisdom a technician can pass onto the customer is that the coolant system just isn’t as easy to service as it used to be. Any work that needs to be done on a cooling system should be done by a technician who is properly trained and has the tools and knowledge of what to look for and how to fix the problem. But if the customer insists in doing the work themselves, then there is one important nugget of advice the technician must give: don’t try to save a few dollars by cutting corners.

“Most of the technical questions that come in are easy,” says Navin. “A car owner will call up and say, ‘It says here I have to flush the system before putting in a stopleak. Do I really have to?’ Yeah, you do! The instructions are there for a reason.”