Hi Robert;
I’m afraid I’m gonna give you a “weak” answer.
The life of a brake disc depends on a number of factors.
1) are the brake calipers and guide pins being serviced correctly? If they aren’t it’s pretty common for the guide pins to bind in the bushings and cock. This creates a lot of wear in a small part of the disc and zero or minimal wear in the rest.
It’s pretty easy to see when the calipers are binding–wear across the disc is uneven.
2) Were the brake pads conditioned correctly after installation? Conditioning creates a glazed layer of material on the lining. A visual inspection of the brake disc will show the lining condition. If the disc is smooth (without grooves) the pads are conditioned. If the disc is rough (grooved) the linings have lost the glaze.
Glazing of organic linings consists of taxiing for 1500 feet at 1700 engine rpm while applying enough brake pressure to hold the taxi speed to 5-10 mph. Then allowing the brakes to cool for 10-15 minutes before use. When the brakes hold at high static engine rpm, the conditioning is complete.
2) Are the discs rusting between flights? A little surface rust is not a problem, but the longer between flights, the greater chance of this occurring. And on that note, where is the airplane based? Obviously a moist sea side climate is the worst case. High desert is the best.
The most important checks are for even wear of the inner and outer brake pads and conditioning of the brake pads.
Let me know what you find.
Steve
