Hey dude, cool it!

 We are rapidly approaching the summer months, which is when all those wonderful little holidaymaking Kiwis hit the highways with their caravans, boats, trailers and often-overloaded cars.

All of this is guaranteed to get some of us hot under the collar as we sit in traffic, but if you think youre hot, you ought to try sitting in the engine bay of a car sometime.

Sadly, engine cooling is one of those regular maintenance things that frequently gets overlooked, and even more so these days, with the modern car being so very efficient.

But they are not perfectly efficient and thus will generate waste heat energy as a result. Over extended periods of time, this will affect engine components adversely  in short, cooking the engine to death using its own energy potential. What a helluva way to go.

So what to do about it? Smart business operators should be sending out WoF reminders with a hint that the coolant system might benefit from a checkover, but you were all doing that already, right? 

And whats the first thing to check? The coolant itself, of course.

In todays cars, coolant is usually a mixture of propylene glycol and ethylene glycol, its either green or red and has various extras added to it, like antifreeze and rust inhibitors.

Now, if you are going to do the right thing by your customers and change out the coolant, you will of course, be doing the right thing by the environment - not just dumping the older, contaminated coolant into the sewer or anything nasty like that, but storing it and calling someone to dispose of it responsibly, wont you?

But why do we use coolant in cars? After all, there are motorcycles which use air-cooled engines and some cars and of course, aircraft engines, why do cars need this chemical goop at all?

Ready for your science lesson? Theres a test at the end

To understand cooling, its important to understand that heat has density, and this can cause cooling problems.

Take a small metal engine component that gets very, very hot. Its hard to cool this component using just air, because air has next to no heat density so, if its moving slowly, there is only a small mass of air to transfer the heat away from the component. In addition, the air will pick up the heat coming off the component, thus becoming as hot as the component itself, not much coolings gonna happen in this instance then, is it?

Now you could blow more air over the part by moving the vehicle faster, but then youre creating noise and using power  heres your first Didja know fact  apparently doubling air speed may take up to 8 times the power, which with todays fuel prices, is something youd rather not contemplate in your F150 truck.

Liquid cooling on the other hand, offers more density in the carrier  liquid  and therefore, you use a minimal amount to effectively carry heat away from the whatever it is.

Youll all be aware of the fact that engines have hot spots, which are one of the mortal enemies of engines. The hot spots are significantly hot enough that they can kill an engine if left out of control.

Where do you find hotspots? At the head, the valves, the pistons and of course, the cylinders  all places where cool air is hard to find. Thats why we use goop.

But cooling is only part of the problem. What about the other end of the spectrum, freezing?

Well, this is where air-cooled engines show their advantages. Simpler design of an air-cooled engine certainly improves reliability, but only in the winter months. Problems can arise when it comes to heat.

You dont need a coolant radiator and you dont need to trap coolant either, which means youll have a lighter engine, which is why air-cooled engines are good in planes and on motorcycles.

Of course, you do have noise issues with air-cooled engines and you have to go a little faster to keep them cooler - but you cant tell that to the local law enforcement officer, so dont try.

Liquid-cooled engines are also better for thermodynamic control. Or keeping temperatures constant, which is something engines seem to like, rewarding users with longer life and less emissions.

It is usually more difficult to get either low emissions or low noise from an air-cooled engine, two reasons why most road vehicles use liquid-cooled engines.

And thats the general stuff out of the way  so whats new in cooling?

First up, a new product from Prestone, as distributed here by Holt Lloyd  its a bit of a mouthful, but check out the new Prestone All Makes All Models Extended Life Antifreeze Coolant, intended for use in all foreign or domestic passenger cars and light duty trucks on the road today.

This patented technologically-advanced formula and traditional colour is compatible with ANY make or model of car or light duty truck and mixes with ANY colour of antifreeze.

The new Prestone concentrated formula also offers up to five years or 250,000kms protection when added to any extended life antifreeze coolant or when your vehicle is flushed and filled with new Prestone antifreeze according to directions on the package.

The vehicles owners manual should always be consulted to determine the specific maintenance and changeover intervals.

New Prestone All Makes All Models Extended Life Antifreeze Coolant has a dual action formula that can provide protection from -65C to 1356C.

It protects all cooling system metals from rust and corrosion including the thin, lightweight aluminium found in many newer radiators.

How the all-new Prestone antifreeze/coolant works with all makes and models

Domestic, Asian and European manufacturers tend to use different antifreeze/coolant formulas in new vehicles. This has caused confusion among consumers  many just dont know which aftermarket antifreeze/coolant is right for their vehicle. The NEW Prestone all makes all Models Extended Life Antifreeze/Coolant is compatible with all these formulas.

The new Prestone All Makes All Models Extended Life Antifreeze Coolant is a patented Organic Acid technology formula that offers up to five years or 250,000kms of protection when it is added to any extended life antifreeze/coolant. When added to a vehicles current formula, is designed to provide the properties and change over intervals of that formula, be it one that offers 48,000kms of protection, 160,000kms of protection or 250,000kms of protection.

The new formula has been tested with antifreeze/coolant formulations that are factory installed by major auto and light-duty truck makers. It may be added to the antifreeze/coolant of any make or model automobile or light duty truck on the road, foreign or domestic.

Motorists should always check their owners manual to ensure they are following the manufacturers recommendations on the appropriate flush and fill maintenance procedures for their vehicle.

The new formula does not offer extended life properties when added to a conventional silicated coolant that requires attention every two years or 48,000kms. It will offer the same protection as the vehicles original coolant without degrading that protection.

The new Prestone 50/50 Prediluted All Makes All Models Extended Life Antifreeze/Coolant formula should only be used to top off the cooling system. For a flush and fill, motorists should use the full concentrate formula offered by the brand to ensure the right mix of water and antifreeze concentrate.

Very, umm  cool. But there is more to cooling than top quality long life formulas for coolant, theres maintenance to think about too, and for that, weve spoken to Mackay from Australia:

While a cars coolant is vital to the survival and longevity of the engine, all the coolant in the world wont save that motor of yours if it cant get around  and how does coolant move? Through hoses of course.

It stands to reason then, that while your choice of coolant is important, the condition of the hoses is equally so.

In conventional water-cooled engines, hoses are an integral part of the cooling system and in fact, are a critical component in safeguarding the engine from excessive heat build-up causing premature and expensive engine fail-ure.

The hose allows for the efficient transfer of coolant between the engine block and radiator. It also eliminates any vibration that may be otherwise transmitted by a rigid connection.

In vehicles of today, a hose has to be designed to withstand the stresses of modern, more compact, but powerful engines that run hotter and at a higher pressure.

Other factors include smaller engine compartments with poor heat dissipation, aggressive coolant additives, and stray (electrochemical) current that may be conducting through the cooling system.

In short, the smaller but more powerful engines of today, work a lot harder than the larger engines that were stan-dard before. More heat is generated, higher burst pressures are required in cooling system components, and hoses have to be made tougher to withstand these demands.

Rubber compounds used in automotive hoses today are predominantly synthetic rubber formulations.

Synthetic rubber offers:

Excellent resistance to high temperatures,

Resists chemical attack (oils, fuels etc.),

Excellent Ozone resistance,

Good resistance to abrasion.

Hose Inspection and Replacement

Since hoses are so vital in maintaining the engine at optimum operating temperature, and prevent costly damage by controlling engine overheating, regular inspection and maintenance of cooling system hoses should be con-ducted at least every six months.

It is also recommended that all coolant hoses be replaced whenever the system is being flushed and coolant replaced, about every 2 or 3 years depending on the vehicles use.

It is important for your safety, that the engine is turned off and has cooled down and the cooling system depressurised before you proceed with an inspection.

The best way to inspect a hose is to squeeze it firmly along its entire length.

Heat

If the hose has a hard feel or has visible cracks along the length it has been affected by excessive heat. A heat-damaged hose also may have a glossy cover along with cracks - in either case, replace the hose.

A good hose should be resilient, yet flexible. Heat deterioration can also produce hidden damage to the reinforcement over time that can cause the hose to burst and fail.

Therefore, an externally good-looking hose may be susceptible to failure due to hidden reinforcement deterioration. The possibility of hidden reinforcement failure is one of the best reasons for replacing hoses regularly.

If the hose is near a radiant heat source such as the exhaust manifold for example, it can soon become hardened and brittle. Ensure heat shields are in place to protect the hose.

Oil/Chemical

Oil is the worst enemy of a rubber hose. A hose damaged by oil can look swollen, or have a soft and spongy feel. Sometimes oil damage can start from the inside of the hose - check the transmission system for leaks into the radi-ator from the transmission cooler or from a cracked engine block.

Many automotive coolants once carried oil to act as a rust inhibitor and water pump lubricant. Coolants with oil-based lubricant or rust inhibitor should be avoided.

Ozone

All Mackay coolant hoses are made from EPDM compounds that are highly resistant to ozone attack. Hoses made from some other rubber compounds may be subject to ozone deterioration.

Ozone is an oxygen compound found in small quantities in the atmosphere, it is also a by-product common near the alternator and other electrical sources in the engine compartment.

Ozone attacks the rubber around stress points (near any bends in the hose or around hose clips) and can be seen when small parallel cracks appear at the point of stress.

Abrasion

Visually check the hose for scuff marks, gouges or other abrasion damage on the cover. Abrasion damage can occur from fan blades, spinning pulleys and belts, or road debris. Splitting around hose clamps is also common.

Any potential contact points that may cause abrasion damage must be protected, either by shielding the hose or rerouting it.

Changing a Hose

When changing a hose, loosen the clamp until it can be moved along the hose and slide the hose off. If the hose is stuck to the fitting, cut from the end of the hose to the beading with a suitable knife; do not lever the hose off with a screw driver, as this can damage the radiator fitting. Hoses with quick-connect couplings can be removed by com-pressing the release tabs.

Brush off the fittings with a wire brush and wipe over with a cloth. Wet the inside the end of the hose with water to make the push fit easier.

Slip both clips over the other end before this is fitted to the radiator, or if the replacement hose has quick-connect couplings push in until locked in place.

Hose Construction

EPDM (Ethylene Propylene type rubbers) is the main synthetic rubber used, however there are numerous formula-tions of EPDM, each one specially formulated to satisfy a specific application demand.

A radiator hose for one car can be made from an entirely different EPDM formulation to another model or make.

The construction of a typical coolant hose comprises three layers, first there is the tube, (this is what the coolant liquid travels through). Over the tube there is a reinforcement material. The reinforcement fibres are knitted onto the tube to provide strength and prevent the tube from bursting under pressure.

There are several different types of reinforcement material used dependent on the application of a particular hose.

Aramid fibre reinforcements used today (such as Kevlar* and Twaron+) provide superior burst strength capacity and heat ageing characteristics right through the service life of the product. (In fact Kevlar is so strong it is also used as reinforcement in bulletproof vests).

For applications where a higher heat resistance is required a special fibre known as Nomex* is used. Other reinforcement fibres used also include Rayon and Nylon.

The burst strength of a hose is determined by the type of reinforcement, the number of knits per square area and the type of knitting pattern. Once again, this could vary dependent on the application requirements of the hose.

Finally, there is the outer cover; that is extruded over the tube and reinforcement fibres and helps hold the hose together while protecting the reinforcement fibres from dirt, grease and moving parts.

The outer cover is also a vital part of the hose construction and has to satisfy the requirements of a particular application.

And then there are all the incidental bits and pieces, most of which, youll find from STOCKS who tell us: Theres no need to lose your cool if you cant find the right automotive cooling parts for a repair job, because the answer is just a phone call away.

STOCKS is likely to have the answer with its range of cooling parts drawn from a range of quality manufacturers around the world. Like Roulands for example.

Roulunds Rofan V belts/multi-ribbed belts from Denmark are among the most trusted drive belts, specified by many European car manufacturers as original equipment. But they are not made solely for European vehicles, they fit practically any car and light commercial under the sun. As a quality belt manufacturer, Roulunds belts provide peace of mind for workshops and their customers.

Selecting the right ROFAN is easy, according to STOCKS, because the part number indicates the top wide and length. The STOCKS warehouses in Auckland, Wellington and Christchurch carry a full range of V-belts (from 9.5mm to 17.5mm top width) and Micro Rib V- belts in 3 rib, 4 rib, 5 rib, 6 rib and 7 rib up to 2325mm long.

ROFAN belts can be purchased individually or in batches and advantageous purchasing is offered to those who want to become stockists, with point of sale wall merchandisers available to hang belts, together with measuring sticks and catalogues.

STOCKS is also the NZ distributor of the well-known USA made Ideal worm-drive hose clamps  one of the best-known brands in the world, huge range, made from marine grade stainless steel and packaged in boxes 10 per size. Hose clamp merchandisers are also available.

Another well-known brand available from STOCKS is Stant thermostats and caps. Made to OE specification, they are very high quality and ultra reliable  there are two varieties of caps, the standard style and also a quick release type favoured - by race/competition people.

The Stant range is complemented by White Knight radiator caps, which deliver fitments for most vehicles on New Zealand roads at very good value for money.

Gates needs no introduction and a variety of moulded radiator water hoses from this top quality manufacturer is also available through STOCKS, along with Gates hose reducers and connectors.

One of the biggest ranges of hoses on the New Zealand market comes under the Motokool brand  its cooling products include radiator overflow hoses, by-pass water hoses and heater hoses.

But the Motokool range goes much further, incorporating fuel injection hoses (EFI hose), vacuum washer hoses, brake vacuum hoses, oil cooler and transmission hoses, high temperature oil cooler hoses, power steering return hose, PVC hoses and rubber fuel hoses. For automotive suppliers, a merchandiser to display the popular Motokool hose products is available from STOCKS.

STOCKS can even supply the Holts radiator maintenance products, including cooling system flush and anti-corrosion additives.

All these products feature in STOCKS new product catalogue, which has just been released in New Zealand.

You can also rest easy in the knowledge that the parts supplied by STOCKS are of the highest quality and come with a factory-backed guarantee, so whether you are fitting them or reselling, you have complete confidence.

All the STOCKS range of cooling system products can be purchased individually or in batches and advantageous purchasing is offered to those who want to become stockists, with point of sale wall merchandisers available to hang Roulunds belts, together with measuring sticks and catalogues.

* Registered Trademarks of DuPont

+ Registered Trademark of Twaron Products VoF.