Glowing brake rotors, take 2. ACTION. - PeachParts Mercedes-Benz Forum

CoyoteStarfish · #1 07-11-2008, 04:02 AM

This one throws me off a bit.

A few months ago, I was zooming down the interstate having a great time. Music blasting, sunroof back. Ahh, great night for a car ride.

I smell something funny, and notice my power is dropping rapidly (floored was only giving me 40MPH by the time I was able to pull into the emergency lane.)

Pull off, smoke billowing from the rear passenger tire well. The rotor was RED HOT. Obviously, cooked my seals and brake pads. Obtained new seals and replaced the faulty seal and the pads and went on like nothing happened.

Two days ago, same thing happens. This time on the driver side, the side I neglected to rebuild.

Both times, after the brakes cooled I could drive them like normal again. I just did not trust it afterwords and promptly proceeded with a rebuild.

What caused this failure? Can it happen to the front rotors?

#2 07-11-2008, 04:05 AM

Faulty master cylinder not releasing fluid back, a rusted caliper or any number of things I can't think of right now. When was the last time you flushed the brakes?

Cervan · #3 07-11-2008, 05:12 AM

Quote:

Originally Posted by ForcedInduction

Faulty master cylinder not releasing fluid back, a rusted caliper or any number of things I can't think of right now. When was the last time you flushed the brakes?

Old brake lines breaking off small rubber partials and going into the caliper?

CoyoteStarfish · #4 07-11-2008, 05:16 AM

Last flush? Never. Probably hasn't been flushed since 1983. Definitely not since I owned it. How often should a flush be performed?

It's on my to-do list now. Up there with leaky oil cooler lines and new CV shafts. Moneypit. But I love her so.

While we are on the subject, what brake fluid is recommended for this vehicle?

BoomInTheTrunk · #5 07-11-2008, 05:46 AM

You are supposed to flush the system every two years. I would also replace all the rubber brake lines. They will tend to swell up on the inside allowing the break pressure to slowly dissipate, this can lead to a sticking caliper. use a dot 4 break fluid like the valvoline synpower.

KarTek · #6 07-11-2008, 05:58 AM

I second the flush idea. It happened on my Corvette once. Over the years, if the system isn't flushed, moisture can build up and foul the components. You might also suddenly find yourself with no brakes after some "spirited" driving when the water laden brake fluid boils in the calipers.

Cervan · #7 07-11-2008, 07:50 AM

Quote:

Originally Posted by CoyoteStarfish

Last flush? Never. Probably hasn't been flushed since 1983. Definitely not since I owned it. How often should a flush be performed?

It's on my to-do list now. Up there with leaky oil cooler lines and new CV shafts. Moneypit. But I love her so.

While we are on the subject, what brake fluid is recommended for this vehicle?

use dot 3 brake fluid, i get it in bulk from walmart for cheap. if you have a 4speed, bleed the clutch too, it will feel alot better. The reason you flush is to get rid of the moisture in the brake fluid, because its hygroscopic (attracts water) What happens is after a few years, it becomes diluted with water, well water boils at a lower point than brake fluid, when fluid boils you get a gas. And gas compresses, so you loose your brake pedal because your compressing the gas now being created (steam) in the brake lines from the hot calipers. It also helps keep the system clean, water creates rust and corrosion wich will block and lock up brake cylinders and calipers.

vstech · #8 07-11-2008, 08:51 AM

dot 3 should be fine, but why? to save $1? the cap on the MC says Dot 4, synpower is cheap in the quart bottles, put in dot 4.
I mean really, we drive awesome 4wheel dual piston calipered brakes. use the right fluid!

Mustang_man298 · #9 07-11-2008, 10:02 AM

If it says DOT4 on the cap, use it, there's a reason the manufacturer calls for it. Mixing fluids or using the wrong fluid can damage things. On my father's Goldwing, he used dot3 in place of 4 once doing a maintenance flush, not realizing it called for the latter. It resulted in a galling/seizing effect in the controls, as there was something in the dot3 that reacted with one of the internal components.