Mechanic in Redlynch

The range is the reason cars here are different

Redlynch sits in the valley at the foot of the Kuranda Range, and a large number of cars based here go up and over it regularly: for work, for school, or because the tablelands are where the weekend is.

A range descent is not ordinary braking. Ordinary braking is short and occasional, and there is time between applications for heat to dissipate. A descent is sustained: the brakes are working almost continuously for several minutes, and the heat has nowhere to go. It builds in the rotors, soaks into the pads, and travels through the caliper into the fluid.

That is what the system is designed for, and it copes, as long as the fluid is in good condition.

Why brake fluid is the item that matters here

Brake fluid is hygroscopic, which means it absorbs moisture out of the air, and it does that faster in humid air. It happens slowly, every year, whether the car is driven or not.

Water in the fluid lowers its boiling point. In normal driving that makes no difference whatsoever. On a sustained descent, with heat soaking back through the caliper, wet fluid can boil, and vapour in a hydraulic system that only works because it is full of liquid means the pedal goes long or goes to the floor. Then a few minutes later, cooled down, it feels completely normal again.

That last part is why it gets dismissed. The driver assumes they imagined it, because the brakes are fine by the time they think to mention it.

It is not a matter of opinion. Moisture content in brake fluid is measurable, and if yours is fine we will tell you it is fine. If you use the range with any regularity it is worth having checked, and it is one of the cheaper things on the brake repairs page.

Two things that are free and worth more than most purchases: use a lower gear on the way down so the engine does some of the work, and do not ride the brakes lightly the whole way, which keeps them hot continuously rather than letting them recover. There is more in our note on brake fade on the Kuranda and Gillies ranges.

The climb does its own damage

The way up is a different test. Sustained load at low speed, often in the heat, with limited airflow.

That is hard on cooling systems, which is why hoses, radiators and thermostats on cars here are worth genuine attention rather than a glance, particularly on anything with some years on it. It is hard on automatic transmissions, which shed their heat into air that is already hot. And it is hard on clutches in manual vehicles, especially anything towing.

If your car regularly does the range, and particularly if it tows anything, say so when you book. It changes what we look at and it changes what we would recommend on transmission fluid, which degrades with heat and is the thing standing between a working gearbox and an expensive one.

The valley itself

Redlynch is green and it is close to the creek, which brings two smaller things worth mentioning. Cars parked under trees collect leaf debris in cowl drains and air intakes, which blocks drainage and puts water where it should not be. And vehicles that sit for a few weeks in this sort of country are the ones where rodent damage to wiring turns up. Neither is dramatic, both are cheap to catch early and irritating to find late.