SOONER or later you have to bleed a diesel. There is only ever really one problem with a diesel engine and that is, no diesel.

That will be because you have run out and the fuel lines are full of air and, therefore, you have to bleed them.

These engines are the heartbeat of industry and farming because, once started, without the pettiness of spark plugs, inconstancy of coils and malign intent of distributors, they are basically unstoppable.

Blokes even stick snorkels on them to drive under water. Impressive.

So it all came back to me watching this character furiously and slightly obscenely working the manual pump to try to get the fuel through the sediment filter and the fuel filter and back up to where it was needed.

Dad explained it all to me years ago, in the middle of a paddock where the old red Fergy had stopped.

He'd loosened the injectors so the pipes leading to each cylinder could prove they were getting the message and he pumped away until the oily fuel spilled over the engine. It started and I reluctantly got on for my six-hour stint.

But this bloke was a mechanic and it's always instructive to watch someone who actually knows what they're doing.

He talked me through the whole process as if explaining to a child. Most of it was familiar but the philosophy of tracing a problem is what experience teaches, methodically dispelling possible faults along the chain of supply of whatever it is the engine isn't getting.

The manual-pump itself was cactus in this case and continued to be so, despite loading it with heavy grease to try to give it a bit more suck, an old trick apparently. Undaunted, he attached an air-hose to the fuel tank and pressurised it to blow the fuel through, which worked a treat. But even with a squirt of Start-You-Bastard and jumper leads to the ute, it wouldn't be in it.

It was approaching the moment when the final solution would probably be attempted, rolling it down the hill in a do-or-die effort to roll-start it and probably to abandon it at the bottom.

It was getting dark by now and I was keen to see the climax even if (especially if) it was an amusing anti-climax.

But suddenly he called it off until morning. Now I'll never know.

These professionals. No sense of adventure.