VTJeep

The car is my roommates '98 Subaru Legacy but this is a generic disk brake question. Skipping the why... The rear disk brakes rubber bushing/gasket on the end of the piston is torn. It is allowing a little brake fluid to leak out when brakes are applied. Driver reports brakes now spongy. In an effort to get it to a mechanic without losing too much fluid can we safely bypass it for now? I.e. crimping the soft line? Or do you just make sure to drive cautiously until brakes are fixed? Thanks all.

quneur

Generally on disc brakes, there's a rubber o-ring that fits in a groove on the piston. There is also a rubber dusk jacket which fits on the edge of the cylinder wall. If the jacket is torn, it should not leak fluid. The o-ring, if still intact, prevents the fluid from escaping. It can however let dirt enter and scar up the cylinder wall and o-ring.

Driving to the shop would depend upon how much it leaks, how far the shop is and the speed limit to get there. To try to cinch off the brake line would take quite an effort. There is considerable hydraulic pressure every time you use the brakes.

A tow is cheaper than repair if you get into an accident.

VTJeep

I guess it's the boot that's torn. It leaks when brakes are applied, but it's all good. He made it sound like he couldn't get parts for now. Woke up and he had a new caliper, disks and pads..

gunmetal_nightrider

Good deal. Make sure he bleeds the system. All calipers.

VTJeep

Well he didn't buy any hardware so IDK if we're going to have much luck. One bolt is already striping a bit. Good ol Vermont rust.. But we will bleed brakes for sure! Thanks.