Keep on rolling
A simple combine maintenance regime will help avoid expensive breakdowns during the harvest season, writes
COMBINES have been in action for nearly a fortnight in some places already in what must be one of the earliest harvests on record. It’s a busy and testing time of the year for these kingpin machines, with long hours in the field sure to throw up some unwanted breakdowns.
Thankfully ground conditions appear to be good for the time being, but any prolonged spell of wet weather will bring soil compaction issues to the fore.
REGULAR 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 lighting 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 therefore 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 in more effectively around warm bearings than cold ones.
This is a fair point, but the main thing to remember is you are trying to get the operator into the habit of doing all vital checks at a given time of day. And don’t forget the golden rule — switch off the engine and remove the key before carrying out any maintenance.
DAILY CHECKS
All 10 hour nipples should be greased on a daily basis. 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 — this is critical during long, hot days when engine demand is at its peak for high yield crops.
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 is a very important part of the combine and contains a lot of moving parts. Every day you need to look 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 10 years, depending on the operator.
Every two days you should check and clean the air filters, grease any 25-hour or 50-hour nipples, and check chain tensions — particularly 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 and slacken. Watch out for broken or bent chain reels on the intake as well.
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? 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.
FAST-WEARING PARTS
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 ÷ fingers for the header auger ÷ engine and hydraulic oil, assorted bearings, bolts and nuts, and a supply of welding rods are useful too.
RUNNING GEAR
Moving to the running gear, during previous harvests tyres may have suffered accidental damage leaving them with bulges, cuts or tears.
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.
Checking the thread 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 with mid-harvest interruptions.
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, remember that 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 and load capacity.
Don’t neglect rear tyres by being tempted to put on cheap replacements; this will greatly reduce the efficiency of your combine, especially in wet weather) and increase fuel use. ÷ 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.
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 any old or partially discharged extinguishers if you haven’t done so already.