Farm Ireland

Tuesday 20 February 2018

Keep on rolling - how to avoid costly combine breakdowns

Avoid costly combine breakdowns by following a common-sense maintenance schedule

Ensure you follow a maintenance schedule to keep your combine running well
Ensure you follow a maintenance schedule to keep your combine running well
A build-up of chaff and dust is allowed to take place at the owner's risk and really tempts fate for combine fires.
At the header end, replace damaged knives and fingers with new parts.
To minimise downtime in the field keep a full set of belts in stock for the combine.
The wobble box needs close attention and is one of the hardest working parts on the combine.
Derek Casey

Derek Casey

Combines have been turning into the first fields of winter barley in the southern half of the country, and spring crops are also quickly ripening.

It's a busy and testing time of the year for harvest machinery, with long hours in the field sure to throw up some unwanted surprises in terms of breakdowns. This week we look at some common sense pointers for keeping combines on the move.

Keep a routine

Once the harvest starts the aim should be a regular combine maintenance routine.

Carrying out this well-rehearsed routine in the morning rather than at night (with the exception of cleaning off the chaff and dust) works best for a couple of reasons; you have good light that is sufficient to have a clear look at the machine in order to find potential problems like worn bearings or cracked parts.

The other benefit is that the combine will be cooler and easier to work around than it would be after a long day in the fields.

Some operators argue that for certain jobs, for example greasing, the grease will travel more effectively in around warm bearings than cold ones.

This is a fair point, but the main thing to remember is to get into the habit of doing all the vital checks at a given time in the day to help you remember them all.

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Daily checks

The most important steps in maintenance are greasing all the nipples, checking the air filters for cleanliness and adjusting the chains for tightness. Every morning, you should grease all 10 hour nipples. A good habit to get into is doing a couple of related jobs in one sequence.

For example, when filling the machines with fuel, check both engine and hydraulic oil levels, and then check the radiators to see if they have sufficient water - critical during these long, hot days.

Stone traps do not necessarily need to be checked every day if the crop is generally clean, but in modern combines access is simple so it is worth taking the 10 seconds needed to have a look.

The header needs to be checked daily for any serious damage to the knives, skids or fingers.

The wobble box should be getting a full inspection in a pre-season maintenance programme at your local dealer or in your own garage.

A wobble box working for around 200 hours per season will generally last for anything from eight to ten years depending on the operator.

Two day checks

Every two days you should check the air filters for cleanliness, grease any 25-hour nipples or 50-hour nipples, and check chain tensions - especially the feeder house chains. On some machines the feeder house chains sit on pieces of timber that look similar to roof slats.

Over time, the chains can wear into these timbers with the result being the chains can slacken.

As well as monitoring the chains for slackness, the timbers themselves will need to be replaced periodically so keep a close eye on them. Watch out for broken or bent chain reels on the intake as well.

Duties that need to be performed once a week include emptying the stone traps when combining trouble free crops.

Other common parts that tend to wear out over time include bearings, chains, belts, sprockets, sickle sections and injector lines. A good visual inspection is key.

Check belt tensions for wear and tear. How do you know if a belt is slack?

First of all, switch off the engine if you are doing any hand inspections.

You should only be able to get half a twist by hand on a belt that is properly tensioned. If you can twist a belt all the way around, 360 degrees, it needs to be tensioned to prevent excessive wearing and subsequent replacement cost.

Tools of the trade

A lot of contractors these days have service vans in which they carry all their tools and spare parts.

A number of grease guns, a wrench set and a socket set are three essentials. A generator/welder combination is also useful to patch up small problems.

To minimise downtime in the field parts that should be kept in stock include a full set of belts for the combine; a belt-tightener pulley; connector links, half links and chains; sickle sections and guards for the cutterbar; drive chains for the heads; and fingers for the header auger.

Engine and hydraulic oil, assorted bearings, bolts and nuts, and a supply of welding rods are useful too.

Check your tyres

Michelin's technical manager, Gordon Brookes says "time, weather and crop constraints make it essential that machinery is ready for use.

Leaving checks until the last minute can result in unexpected machine downtime."

The tyre expert said that during previous harvests tyres may have suffered accidental damage, leaving them with bulges, cuts or tears.

Checking the tread area and sidewalls right down to the wheel trim helps detect problems as soon as possible. Leaving damage unchecked can result in costly tyre failure and harvest interruptions.

Long periods of inactivity since last year's harvest can leave tyres with a flat spot due to one section of the casing being deflected, creating massive vibrations on the road.

To combat this, mark the affected area of the tyres, move the combine into direct sunlight with other sections of the tyres deflected. Warming the tyres in the sunlight will see the casing return to its normal shape.

Ensure that tyres are inflated to the correct pressure ahead of the harvest, considering whether the combine will be used on side slopes or intensively on the roads. If you need new tyres, take tyre choice seriously.

Tyre choice can make the difference between a good harvest and a great one, and for most combines and foragers there is now a tyre which limits soil compaction and disturbance on headlands whilst offering greater operator comfort, manoeuvrability and load capacity.

Remember, rear tyres can also affect the efficiency of the combine (especially in wet weather), yet they are commonly neglected.

Combine fires

For a few unfortunate operators each year disaster strikes when a combine is destroyed by fire. To reduce the chance of having such a disaster, remember two points: prevention and preparation.

Be extra careful to remove the fuel for any potential combine fire, i.e. built up grain, chaff and dust layers on a machine.

Warn drivers to have a regular cleaning schedule each evening before finishing up. Using a compressor, blow away any crop residue that has become wrapped around bearings, belts and other moving parts.

These can generate significant heat, even when the machine is parked up for the night.

Specific areas to blow out include:

The engine - especially the exhaust manifold, turbocharger, muffler and exhaust pipe

Hydrostatic pump, motor, hydraulic lines and tubes

Brake and transmission housings

Electrical components

Engine drives and all moving parts

Batteries and battery cables

Straw chopper drive gear compartments

It is possible to eliminate some heat sources from the combine.

Covering up hot exhaust surfaces and replacing any exposed electrical wiring is a good place to start. Worn bearings and belts can easily generate enough heat to make fine dust and crop residue catch fire.

Get the combine operator to take control of his machine and check these areas daily. Document the problems, make repairs as necessary and sign off on them as they are corrected so that you can keep on top of running costs.

While the hope is that it doesn't come to it, in the event of a combine fire you have to be prepared. Always keep at least one fully-charged and certified dry chemical fire extinguisher in the combine cab.

Mount a second fire extinguisher on the outside of the machine that can be reached from ground level. Finally, remember to check and recharge extinguishers before the harvest really kicks off.

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