2000 Ex v10 and had a brake line burst under the drivers door. The line was completely rusted, cant believe they use a material that would rust like that.

I had to drive the vehicle home a short distance with no traffic and I had slight braking from the rear wheels with foot to the floor. Can anyone explain how that happens.

Many thanks....

 

How it happens ?

Brake hard lines are steel that has a corrosion coating, the coating helps but as it ages or gets chipped, corrosion sets in. In dry arid climates brake lines can last a very long time. ( I have a 75 year old jeep and the original lines are in great shape ) in humid,wet or salty environments they can corrode surprisingly quickly. Not unheard of for a line to fail from corrosion is as little as 5 years on very salty wet roads. Newer vehicles have better corrosion coatings but as recent as the late 90's maybe mid 2000 it was still a issue.

As a precaution, a full under vehicle inspection should be performed to find out what else's is rusty and doomed to failure. Oil pan, drive lines exhaust, frame, body mounts... it's all steel and subject to corrosion.

 

Look into copper/nickle lines. They are super easy to bend by hand, and won't be rusting anytime soon. Just get a flaring tool and make up the line.

 

Thanks guys, Copper/Nickel line were the replacement. I don't think I have seen a vehicle with some degree of rusting lines, the tough one is to know how really bad they are. The Ex an 8000lb vehicle suddenly no brakes which is what happen to me, fortunately I wasn't braking from highway speed.

My main question was even with no brake line (that runs close under the drivers door) the rear brakes very partially operated with foot all the way down on the pedal. Does anyone know why that is?

 

The rear brakes still functioned because they are on a seperate circuit.

The master cylinder has 2 pistons and 2 ports on seperate circuits. Precisely for this reason.
If one circuit fails the other still works.

 

My guess would be that this has everything to do with the (pardon me if I get the phrase wrong) dual diagonal braking. If memory serves, loosing one wheel means you actually loose 2...but two continue to work in a small way....

I assume the Excursions have this...I don't think I've ever owned a car without the dual set-up. Perhaps mandated in the late 1960s?

 

Excursions do not have diagonal systems. The braking you felt had to be the front. They are on a different circuit. The rears are based on one line that goes to a flex that t's at the left side of the rear axle. If you saw motion, that would just be show there was enough pressure build up available in the lines to wiggle the calipers.

 

He should have had emergency brakes, at least in my 2001 F250, you have emergency brakes if you loose main brake system. I drove home using E brakes when I lost master cylinder pressure.

 

Thanks for the clarification The2003Excursion. I was under the impression there were two "systems"...


I know when I blew a rear brake line in my former Bronco..I lost all brakes. For better or worse I was towing my trailer at the time so I had trailer brakes.

 

Thanks all. I had only noticed one brake line running aft but the rear brakes were partially activating, not the front. Foot to the bottom of its travel and the rear wheels felt like they were dragging me to a stop. Definitely going to have to look under and check config'n.