Heat and dust: the July checklist

Everyone plans for winter. Nobody plans for July, and July is when machines actually go down — because the ground is finally good, so the iron runs hard, hot, and in its own dust.

Heat: the hydraulics

Hot oil is thin oil. Thin oil leaks past seals that were fine in May, cools less well than it should, and loses the film that keeps metal off metal. A machine that gets slow and vague in the afternoon is usually telling you its oil is too hot, not that it is worn out.

• Clean the coolers. Chaff and dust in the fins is the single most common cause, and a blocked cooler looks exactly like a healthy one from ten feet away.
• Check the oil level cold and hot. Low oil runs hotter, which thins it further, which runs it hotter.
• Watch for afternoon-only symptoms. They are the tell.

Dust: the engine and the operator

Dust is abrasive and it goes everywhere air goes. The air filter is the cheapest part on the machine and it is the only thing between a dry site and the inside of an engine.

Check it more often than the schedule says in dusty months. The schedule was written for an average, and July is not average. And do not clean a filter by banging it on a tyre — that is how you get the dust past it.

Heat: the operator

A cab in direct sun with a failed air conditioner is a genuine safety problem, not a comfort one. Tired operators make the mistakes that hurt people. Fix the air conditioning before the season, not during it.

The July walk-around

1. 01
   Coolers and radiatorsBlown out, properly, and looked at rather than glanced at.
2. 02
   Air filterChecked on a dusty-month interval, not the book interval.
3. 03
   Fluid levels, all of themCoolant, hydraulic, engine oil. Heat finds every low level you have.
4. 04
   Hoses and sealsHeat ages rubber. The hose that seeped in spring is the hose that lets go in August.
5. 05
   Belts and the fanCooling depends on them, and they are cheap.
6. 06
   Air conditioningBefore the heat, not during it.

And fire

Dry vegetation, hot exhausts, and accumulated debris in an engine bay. Keep the bay clean, know where the extinguisher is, and take the interface between a hot machine and dry grass seriously. This is a coastal summer with a dry season, and it has been getting drier.