92 LeSabre blown brake line

[kok328]

I just got done replacing the plastic water pump bypass to intake manifold fitting and now I've blow out the right rear brake line.

I manage to replace it but, I don't understand what happened after the line let go.

What I mean by this is that I'm used to having a split brake fluid resevoir to serve the front and rear separately. I also discovered that each wheel has it's own brake line off the ABS controller. This being the case and also having a split resevoir to avoid total brake loss, I found that with just the right rear brake line ruptured, I had NO brakes AT ALL.

My question is, if the front brakes provide over 50% of the stopping action and just one rear break line broke, then why did I not have any brakes at all and especially in the front?

The individual lines off the ABS made quick work of bleeding as I only had to bleed the replace line to regain my brakes.

[spinne1]

With an open brake line, the hydraulic pressure needed to stop the car when you hit the brake pedal is not generated. In other words, there is no back pressure forcing the other three lines to receive the fluid at a pressure sufficient to stop the car. All lines are necessary for the brake system to operate. There are cases where the leak is much slower and thus you have brakes for a while until your fluid runs out (the pressure generated by the fluid far exceeds the loss of pressure by the tiny leak).

Anyhow, be glad you were not driving your car in busy traffic when you discovered you had no brakes.

By the way, you probably should take a good look at all your brake lines, as well as the rubber hoses between your lines and the front brake calipers. I found that the rubber on my wife's 92 was about to give way (so I replaced them), and I also discovered that both rear and the front left brake lines of my 92 had rusted through. My car's brakes were due to fail at any moment when I discovered the damage! In fact, when I went to wipe the rust off the lines broke in two in my fingers. Scary! I replaced all the lines. (and now my master cylinder is leaking).