Brake failure, yay!

[FordPrefect]

Hey, I just replaced the guibo on my ride, and after enjoying a few mild summer days, the brakes are broke.

My dad took the car for a spin, and complained that the car didn't have the power it used to, and didn't want to go. Then the brakes completely failed on him a block away from home, with zero pressure.

I checked it out when I heard about it; the brakes have pressure, the reservoirs are full, but brake fluid has leaked out the front wheels. The working theory is that the brakes locked up somewhat and then failed.

So, while I wait out the approaching thunderstorm, thought I'd access the Fiat thinktank here. Any good theories?

I also think the exhaust or something is creaking a bit over bumps now after the recent guibo operation, but that's not quite as pressing, I can check it out when I get it up to look at the brakes.

[kilrwail]

I would examine the rubber lines between the caliper and the body - they will dry out and crack with age.

[htchevyii]

I've heard of old hoses collapsing and not releasing pressure, thus holding pressure and not letting the calipers release. It sounds like you need to tear it down and see where it's leaking, clean and lube the slides and go from there.

[FordPrefect]

I took a good look at it today, and to my surprise, no brake fluid has leaked out. What I previously took to be brake fluid was actually wheel grease, with no visible fluid leaks anywhere near the wheels or the master cylinder.

I jacked the car up, and found all of the wheels dragged slightly, but not much. Took the car out around the block as the brakes had pressure, and found the brakes travel a bit further than normal, and it's not easy to stop the car.

So I'm not sure why the brakes failed earlier but are decent now, nor why wheel grease would escape out the front wheels. Maybe that's unrelated?

[So Cal Mark]

if the brakes are dragging, driving will create lots of heat. It's possible to boil the fluid and melt the grease. Once the fluid returns to liquid you have pedal again

[FordPrefect]

I'm still not sure what caused the dragging in the first place, I'm replacing a hose and the fluid, hopefully that will help.

[mbouse]

dragging should be coming from a caliper piston that is not retracting. could be that the hose is collapsing and holding pressure, but also could be a piston that is corroded and sticking itself. also, could be that the piston is near fully extended due to worn pads.

also, those calipers were meant to "float". if the caliper slides on the caliper and/or on the bracket are corroded or dirty,the caliper cannot float

[FordPrefect]

The thing is, both front brakes were dragging at the same time, enough to melt the wheel grease, and probably boil the fluid, but they aren't dragging that much anymore for some reason.

[mbouse]

question?

master cylinder sticking? is this possible to produce these results?

[FordPrefect]

I haven't been able to reproduce it yet. I'm hoping fresh fluid and a new hose will help, as the left front brake hose looked a little worn, like maybe it was twisted at some point, or something rubbed against it.

[FordPrefect]

Ok, I've been driving around for a while and brakes seem fine, just have a few questions:

1. The new e-brake cable is a bit long, the adjusting nut is adjusted as far as it goes in order to have any effect, is there a way to tighten that thing a bit more? Is there a way to shorten the cable maybe?

2. The exhaust pipe is really close to the cable, is there any possibility of heat damage to the cable?

[baltobernie]

1. You can use something like this:
http://www.napaonline.com/MasterPages/N ... +Shortener

2. Pretty much all Spider models have this problem. Most cars have the plastic sheath burned off in the vicinity of the exhaust pipe, but it doesn't seem to affect the function of the brake.