A pre-summer AC checklist for Hunter fleets

Why check now, not in January

A slow leak, a dirty condenser or a tired fan can go unnoticed all winter. Hot weather is when they show up, often several at once, and usually when every other fleet is after the same techs.

There's a safety angle as well. SafeWork NSW's heat guidance calls for regular AC servicing so systems don't fail in a heatwave, and lists air-conditioned cabins in vehicles and mobile plant among the ways to manage heat. Our post on why hot cabs are a safety issue covers that side in more detail.

Start with a simple register

Before anyone touches a vehicle, pull together a list. A spreadsheet is fine. Record the details below for every vehicle and machine with AC, and put the ones you can least afford to lose at the top, because they get checked first.

• Rego or asset number, type, and where it's usually based
• Refrigerant type from the AC label under the bonnet, which will usually be R134a or R1234yf
• Date of the last AC service, from the service sticker or your own records
• Any complaints from drivers or operators last summer
• How critical it is to keep running through the hot months

Quick checks you can do yourself

These need no tools and take a few minutes per vehicle. Have drivers run through them at pre-start, or do a walk-around at the depot one morning and note anything odd against the register.

• Run the engine with the AC on, fan on high and recirculate selected. The centre vents should blow properly cold, not just cool.
• Check it stays cold at idle, not only when the vehicle is moving.
• Try every fan speed, vent mode and temperature setting. One that doesn't work points to an electrical or control fault rather than gas.
• Note any musty smell from the vents, which often means a dirty cabin filter or a damp evaporator.
• Check the cabin filter if it's easy to get to, and replace it on schedule. On dusty sites, check it more often.
• Look at the condenser in front of the radiator. Bugs, grass seed, mud or dust packed into the fins stop it shedding heat.
• With the AC on for a few minutes, check the cooling fans are working and not noisy.
• Check AC hoses, joints and the compressor for oily, dirty patches. Oil escapes with leaking gas, so grime on a fitting is often the first clue.
• After a run, a little water dripping under the vehicle is normal. Water in the footwell isn't, and usually means a blocked drain.
• Listen for squealing, grinding or rattling when the AC kicks in.

What to leave to a licensed tech

Anything involving the gas belongs with a licensed technician: connecting gauges, adding refrigerant or opening the system for repairs. Refrigerant handling licences cover commercial vehicles, off-road vehicles and automotive plant as well as cars, so the same licensing applies to an R134a ute, truck or loader.

A proper pre-summer check should cover the points below. Update your register as each vehicle is done, so next year's check starts from facts rather than memory.

• A leak test of the whole system
• Pressures and vent temperature with the system working
• Condenser, fans, belts and hoses
• Compressor operation and noise
• The electrical side: fan speeds, controls, relays and wiring
• Gas only where it's needed, after any leak is fixed: recover, vacuum, leak test, recharge to spec and a performance check
• A service label on the vehicle recording the work, the gas and the oil

Book it in batches

If your vehicles come back to a depot or yard, have them checked there rather than sending them out one at a time. A mobile tech can work through a line of vehicles in one visit, between shifts or while crews are on other jobs, and nobody loses time driving to a workshop and back.

Put the flagged vehicles first and group the rest by location. Sort out keys, access and a contact person before the day, and ask about weekend work if weekdays are too tight. If you'd rather not organise this from scratch every year, a preventative maintenance program can put AC checks on a regular cycle.

Plan for the one that fails anyway

Even a well-checked fleet can lose an AC on a hot day. Decide now who drivers call, whether there's a spare vehicle, and how the crew will manage the heat in the meantime. Write it down so the plan doesn't depend on who happens to be in the office.

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