Farm Ireland

Tuesday 12 December 2017

Frozen in time

Bruce Lett

After the 'big freeze' comes the inevitable 'big melt' - never more so than this Christmas and New Year when we had some of the coldest conditions ever experienced by many of us. The extreme cold is hard on man, animals and machines, and especially hard on man if the machines don't work.

As a rule, we experience relatively wet and miserable, but warm, conditions compared to many of our neighbours. Our moderate temperatures rarely have an effect on the functioning of tractors and equipment. As a result, we are often ill- prepared for the extremes.

It's all a bit retrospective at this stage, but it's certainly a worthwhile exercise for the future to take a look at what we can do to avoid damage in the extremes.


As stated in an earlier article on winterising sprayers, when water freezes it expands by about 10pc and is incredibly powerful, exerting destructive forces on whatever may try to contain it. Anti-freeze, or coolant, provides two functions: it stops the water freezing and provides a rust inhibiting function to the cooling liquid, which runs in a mostly metal/ cast iron environment.

Many may doubt the quality or effectiveness of the anti-freeze in their tractor or vehicle and, as a result, may drain and refill with new anti-freeze. To remove this uncertainty there are several different types of testers available. I bought the one featured here in the local auto factor for just €5. It is the latest hydrometer-type which features discs, which will float instead of the older graduated bulb type, which can be off-putting to some.

On the featured tester (right) the first coloured disc represents -70°C protection, the second -150°C, the third -230°C, and so on. To use, just squeeze the rubber head on the top to draw the vehicle's coolant liquid into it until the glass section is full. Hold it upright to allow the discs to float freely.

After the recent cold snap, you would require two floating discs to offer adequate protection. Testing several vehicles on the family's farm threw up a couple of surprises. A 1998 Nissan pick-up, with the original coolant, still floated three discs. One of the tractors only offered minimal protection during the recent freeze, floating just one disc -- as it turned out it had a slow water leak in the radiator and topping it up, rather than curing the problem, had thinned out the coolant's performance -- a good example of how easy you can be caught out.

Also Read

One old-timer didn't require a test as the freeze had knocked a lump out of the thermostat housing -- again demonstrating the power of frozen water. In this case the thermostat housing is part of the cylinder head and the repair requires the cylinder head to be removed to weld the piece back in. The picture (left) shows where the ice expanded outwards and pushed out a section of the housing -- again as a result of a water leak that allowed the anti-freeze to be thinned out.

The €5 tester could have saved a lot of bother if used early on before the harsh conditions set in. Rather than draining a vehicle's cooling system down unnecessarily, or doing nothing at all, a few minutes with a €5 tester will verify the condition of the vehicle's coolant, putting at ease everyone involved.


The power of a battery is often referred to as cranking amps (CA). CA is the number of amperes a lead-acid battery at 0°C can deliver for 30 seconds and maintain at least 1.2 volts/cell (7.2 volts for a 12-volt battery). In other words, the CA determines how much power you have to start your vehicle in most climates.

The basic job of a battery is to start an engine; it must crank, or rotate the crank-shaft while at the same time maintaining sufficient voltage to activate the ignition or fuel system until the engine fires and maintains rotation. This requirement involves a high discharge rate in amperes for a short period of time.

Vehicles demand more from a battery in freezing temperatures as the engine oil thickens and makes the engine harder to crank over. Extreme cold conditions, such as those seen recently, also dramatically reduce the speed at which chemical reactions can occur within the battery, while increasing electrolyte resistance (ability to produce electricity).

Another battery rating often quoted is the CCA, or cold cranking amps, which basically denotes the battery's capacity in extreme cold.

Since it is more difficult for a battery to deliver power when it is cold, and since the engine requires more power to turn over when it is cold, the CCA rating is defined as the number of amperes a lead-acid battery at -17.8°C (0°F) can deliver for 30 seconds and maintain at least 1.2 volts per cell (7.2 volts for a 12-volt battery). In other words, the CCA determines how much power you have to start your vehicle on cold winter mornings.

It is important to keep batteries at a full charge during periods of extreme cold. Batteries in a discharged state are susceptible to freezing, which can cause damage to the plates and battery container. As part of regular service check, maintain the level of electrolytes in the battery to help keep it in good condition. Top up as necessary with distilled or tap water.

In really cold climates vehicles will often be fitted with an engine heater, which is plugged into the mains at night and aids starting in the morning.

Jump starting

Any degree of cold will test a battery's condition. Often it will perform OK in moderate temperatures but appear flat when subjected to cold. Jump starting is the first response to get the show on the road again.

For tractors, you will require a 'heavy' set of jump leads to transfer enough power. It is very unlikely that simply attaching jump leads will be enough to start the vehicle, so you will require a charge from the jumper vehicle.

It is critically important to connect the jump leads correctly, with the ignitions of both vehicles switched off. Any power surge could cause catastrophic failure of one or more electrical components in either vehicle, and with multiple ECUs or black boxes in many modern vehicles this could get expensive.

Connect the red lead to the + (positive) pole on each battery first and then the black lead to the -- (negative) pole. For your benefit I have highlighted the -- and + poles and terminals on the battery, but often it is not so easy to see when batteries are tucked away in darkened battery trays. To help with the orientation when it is difficult to see, I put a red cable tie on the + lead -- this removes the doubt when 'jumping'.

With everything connected, start the jumper vehicle and run on a good throttle for a few minutes. Then try to start the flat vehicle. If it doesn't start, run again for twice the length of time. If it still does start, switch off the jumper (ignition completely off) and carefully disconnect the jump leads, black then red. There will still be a load difference between the two batteries, so be careful when disconnecting the first clamp because it may spark, so do as quickly and cleanly as possible to avoid injury or electrical surging.

Run the jumpee for a good spell to ensure the battery is charged and the engine is warm enough to easily restart after the jumping. Ensure the fan belt is sufficiently tight to run the alternator without slipping, because, in the cold, the demands on it will be significantly increased.

Irish Independent