DIYbanter - View Single Post - Brake pedal goes half-way to the floor, only the first time

J Burns

On 11/2/14, 10:13 PM, wrote:
Your collapsed lined had nothing to do with clamping. Lines fail -
and the failure you mention is COMMON.. Clamping the lines WORKS, and
if done with the proper clamp it will not damage a good hose. Might
damage one that is already failing - which needs replacement
regardless.

I wish I understood what happened with that car. At first, I assumed
that the piston was jammed with dirt or corrosion.

If the line had collapsed, I would have expected pressure from the brake
pedal to open it so I'd get full braking on that wheel.

As I haven't seen it on any other vehicle, might those lines (just the
front) have been manufactured differently from most lines?

The other explanation is that something had been done to those lines
that isn't done to most lines. For example, I have read that if you
remove the caliper, you should be careful not to turn it 360 degrees (1
turn in the line) when you refasten it; a twist could cause the line to
burst later on.