Calipers replaced, mushy brakes. Advice?

[Kaz]

1998 Dodge Neon WITHOUT ABS. Front Disc, rear drums. Kind of a long story, but I’m trying to be complete here, so bear with me. Where brakes are concerned, this isn’t my first rodeo, but this one is a head scratcher for me.

One day, the brake pedal went right to the floor. The car ultimately stopped, but it was pretty freaky. Turns out there was a brake line rusted on the left rear line. I got a buddy to show me how to splice new line onto the brake lines using a tubing cutter and compression fitting. For this particular side, sadly, we had to drop the gas tank to get to it. We repaired it and all seemed well.

About a week later, the Right Front tire was smoking. Turns out, the smoke was coming from heat generated at the right front caliper, melting the plastic wheel covers. I decided to replace BOTH front calipers. Now, I only replaced the calipers, and did not replace the pads, since there was plenty of friction material left on the pads, although, admitedly, you could see some heat degredation on them. As suspected, the right front caliper was siezing – it was the slide pins. The left front caliper had a worn boot, and you could occassionally smell heat from that side, so, of course, that caliper was replaced too, again, using the old pads.

While bleeding the right front with a two-man system, we were getting great resistance on the brake pedal, and just at the last opening/closing of the bleeder valve, you could hear a hiss, and the buddy reports the pedal going to the floor again. I thought there might be something wrong with the compression fitting that we had done a week earlier. Nope. Now it was the right rear line, just about the same location as the left rear line (gotta love design). The line had rusted through.

This time however, we didn’t need to drop the gas tank, and found a spot about midway under the vehicle that was “splicable”. The problem was, that it was too tight of a space to use a tubing cutter (yes, the tiny ones) without risking putting more stress on the old lines. So my buddy used a hack saw blade to cut through the line. That took like… forever. We made sure the master cylinder never ran dry during the process. So, we bent and spliced new line onto the old line and connected it to the right rear. Upon bleeding the system, we found that no fluid was coming through the bleeder bolt. (slaps forehead) what the hell?

Turns out the brake hose on the right rear drum brake was plugged. I bought a new brake hose, and connected it, and again bled the system. I suspect that some rust had gotten in the system and plugged that brake hose. All was well, except…

Pressing on the brake pedal is rather mushy. The pedal will not go all the way to the floor, but it seems to travel quite far. The car will not stop on a dime, like it should. You have to increase your stopping distance. You can’t “skreetch” the brakes.

Not having a buddy any longer, I put cardboard under all the spots where work was done on the line, and pressed the brake pedal, forcing fluid through the system. There were no visible leaks.

Is it possible I have another plug in another brake hose? Is it because I used “less than ideal” pads? Do I have compression fitting issues (although they do not appear to be leaking). I’m not losing brake fluid, at least that I can tell.

Any advice? I mean, you know, it’s brakes…

Topic

[Bill]

Not sure bout the USA but copper is illegal in Ontario Canada as well as compression fittings. I do admit though that I have used nickel plated copper and it’s a dream to work with. It’s much more expensive than steel.

[Kaz]

I don’t know what the burst strength of copper alone is, but 90-10 Copper Nickel brake lines are sold here at approximately twice the cost of standard brake lines in the US, and about 4 times more expensive than what the UK poster quoted. The copper nickel are rated well within the limits of automotive hydraulic pressure (approx 15,000 psi). I know that making flares on copper lines is just as dicey as it is on steel lines, especially since it’s a softer metal, and tensile strength is an issue (galling and splitting). I’m not sure about Cu/Ni lines.

There’s an interesting article on Cu/Ni used in this application here:

Automotive Hydraulic Brake Tube: The Case For 90-10 Copper-Nickel Tubing

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