The hydraulic disc brakes on my MTB, SRAM Guide RSC, are 7 years old with several thousand miles. As I was bleeding them yesterday, when I applied vacuum to the caliper end, it drew air in through the lever, even while the lever was fully depressed/activated. The only way the air can get in, is past a bad seal along the hydraulic line, past a leaky piston in the caliper, or past the seals on the pistons in the master cylinder. When I applied the vacuum, I could hear air leaking through the master cylinder/piston inside the lever, so that narrowed it down. I hope that rebuilding the lever with fresh seals will fix it, in other words the problem isn't scoring on the inside of the master cylinder.
I've given these brakes regular maintenance, doing a fluid flush & bleed every year. They've been fine until now.
Is this a normal lifetime? How long do the seals in your hydraulic brakes last? Is it always the lever piston seals that fail, or have some of you seen the caliper pistons start to leak?
I've given these brakes regular maintenance, doing a fluid flush & bleed every year. They've been fine until now.
Is this a normal lifetime? How long do the seals in your hydraulic brakes last? Is it always the lever piston seals that fail, or have some of you seen the caliper pistons start to leak?