bursted brake line ??

cary · 09-29-2003, 03:36 PM

I'm still trying to freshen up my son's car.
I finished up the brakes. Then I moved on to bleeding.
I have a Pressure Bleeder.

But I BLEW up the right rear rubber line. Blew a hole in the side of it. So smart guy that I am. I went and took one of my project car. Blew that one up. So I took off the other one, and blew that one up too.

Now I think these are just 30 years old and worn out. Or am I missing something ?

I'm running the pressure bleeder at 15 lbs. Less than what I do on the 911.

Jim Smolka · 09-29-2003, 06:09 PM

Not sure why they would fail. Typically, a braking system will generate over 10 bar of hydraulic pressure.

D7N7MASTER · D7N7MASTER's Garage

Holy DooDoos Batman! I have never-ever heard of that happening. On ANY car... I have no clue. How can U BlOW UP anything if you are pulling a vaccum??? Are you pullin' vaccum from Gray Davis?

Jim Smolka · 09-30-2003, 04:08 AM

I think he is using a pressure bleeder that applies pressure to the resevoir.

Side note, does anyone know if the MC is able to multiply the input pressure. If so, this could explain the burst problem

Dave at Pelican Parts · Dave at Pelican Parts's Garage

The MC should not be able to multiply the pressure. The brake lines themselves should be good for quite high pressures--if they blew up, they would have failed the first time you used them, most likely.

Time for new lines. I recommend rubber over the popular SS-braided ones. I know of several failures of the SS ones after only a couple of years, while stock rubber ones last about 20-30 years.

--DD

cary · 09-30-2003, 09:11 AM

30 years is up I guess. LOL.

Yes, I'm using a pressure bleeder. I guess I'll order some new lines. Both these cars are "barn" cars. Sat for years without being used.
Glad I caught it now. Rather than it bursting on my son.

sammyg2 · 09-30-2003, 09:50 AM

The MC could put up more pressure if the input pressure was increased but it would be cummulative not multiplied. In order to multiply the pressure the input force (from your foot) would have to be drammatically increased. One possibility is that the lines were weak and were twisted during removal or installation rupturing the weakened area.

You need to make sure the brake lines are not in a bind and are not put in a bind during the removal or installation process. The hoses are designed to keep pressure in and to be able to flex a little, but are not designed for torsional strength. When the fittings get that old it is hard to keep from twisting them.