way OT - Dodge Neon brakes

[NH2112]

Saturday a friend of mine was having tires mounted & balanced at a Sears store. When we left (me in my truck, her in her car) she lost the brakes in the mall parking lot and narrowly avoided hitting another car. The tech at Sears said that a brake line had split due to corrosion (it's a 95) and that all the brake fluid had leaked out. I asked how that could be possible since all cars (or so I thought) had dual-circuit brake systems, and he showed me how the master cylinder only had 1 reservoir and was indeed dry. My question: How can a car be made with this obvious safety defect? The parking brake sure won't stop the car from speeds much over parking lot speeds, and not many people will have the presence of mind to grab the handle anyway. I'm like the least litigious person alive, but does anyone think this could be grounds for a lawsuit?

[chuntag95]

That depends on the maint done and if she can prove she followed the schedule. If the original brake fluid was still in the vehicle, then your answer is no. 8 years is a long time for the fluid to suck up water and have a chance to rust through the lines. If she changed the fluid every year or two and it looks like a line defect, then maybe.

Most vehicles have only one tank of fluid. I had the same thing happen on a 73' Step van and had to put it into reverse to keep from creaming an old lady in a Cady. Every seen a bread truck hop? :eek: It was the rusted line and near crunched experience that gave me my brake fluid changing nature today.

[NH2112]

It's true that most vehicles only have 1 tank for brake fluid, but except for some very old vehicles (mid 60s or earlier) and this Neon, every vehicle I've ever seen had 2 chambers in the fluid reservoir - one for the front and 1 for the back brakes. This, along with a shuttle valve in the piston itself, ensured that a leak at the rear brakes wouldn't cause the front brakes to go, and vice versa.

I can't recall ever seeing a service schedule for brake fluid. She's not the original owner in any case so it'll be hard to prove whether or not the fluid was changed before she got it. And I don't think water itself will cause rust, doesn't there have to be free oxygen (i.e., air) for rusting to happen? My question wasn't about the split line, since I live in NH and rust (on the exterior of the lines) is a fact of life up here - although my 85 C1500 has all the original brake lines, and a 78 F250 I work on from time to time has most of its original brake lines. Both of them have been in New England since new. My question is whether or not going back to a single-circuit brake system with no safeguards - 35 or so years after they began to be replaced by dual circuit systems for safety reasons - amounts to negligence or whatever on the part of Chrysler.

[Rockin]

THe brakes should be in a cross fashion, a front left and right rear on one circuit and a front right and left rear on the other.

There should be a single reservoir that feeds both circuits. If one circuit goes out, the other still has fluid in it for a while. The switch on the master cylinder that turns on the brake idiot light is tripped when the pressure drops on one circuit.

If you were to tear the master cylinder apart, you should see a couple things. First the circuits are front and rear on the master cylinder, two lines coming out of each circuit. If you remove the master cylinder piston, you'll find two seals and two inlets, one for each circuit. The piston will look like: x----x---- where each "x" is a seal. In front of each seal will be the line outlets. When the brakes are pressed, the seals will pass the inlets. When released, they will be behind the inlets.

[NH2112]

I thought they'd be split into front and rear circuits, but not on this car - there wasn't a drop of fluid in the reservoir and the pedal was sitting on the floorboard. In other words, a leak at one wheel caused ALL the fluid to leak out and left my friend with NO brakes whatsoever.

There's only 1 line coming out of this master cylinder, going to the proportioning valve/brake warning switch. I understand what you're saying about how there "should" be 2 separate circuits but on this car there aren't, and a leak in 1 line caused all the fluid to leak out resulting in no service brakes. If my friend had decided to get new tires in the town where she lives and drive to MA as originally planned, in all likelihood she'd have lost her brakes on an offramp and things would have turned out very differently.