Brake freeze?

[LandYaghtLover]

Odd problem that may have been a one off. Washed car yesterday and drove for some time after. Also had it in my garage which has yet to get below freezing. Then today I am on the highway and I notice my economy needle is pegged straight down. The cruise control was even a little jerky. I figured a vacuum leak even though all my engine vacuum tubes and rubber are new. So i pull over and briefly notice a burning/foundry smell. Thinking belt I pop the hood and everything is fine. Also no vacuum hiss or smoke. Engine seems fine. I let the car idle for a while then get back onto the highway and all is well, needle never gets more than a quarter inch from left.

So my thoughts are that residual water in the brakes caused them to freeze up? And sitting allowed the ambient heat to melt the ice. I did go from garage to highway before the car engine even warmed up. Possibility? Or is this a common issues with the brake design?

[Hit Man X]

Ever flushed the brake fluid? It is hygroscopic and needs to be flushed at a max of every few years. Why? When it freezes it is like a box of knives stabbing the o-rings in the master cyl. Not what you want...

SO you could have a failing MC as it is sticking internally or a dying caliper. Both are easy to replace, just a pain in the ass.

I had this happen to my SDL just recently. Pull a wheel and check the pad material, if it is melted (as mine was) you have found your problem.

[LandYaghtLover]

I have not flushed it yet. Been thinking of it. The MC looks brand new. The OP replaced it, but it could have been a couple years ago. Guess it cant hurt since brake fluid is pretty cheap.

Anything specific that I should use for a fluid?

[compu_85]

Anything which has DOT4 on the bottle will be fine.

-Jason

[Chas H]

Originally Posted by compu_85

Anything which has DOT4 on the bottle will be fine.

-Jason

Unless DOT 3 is recommended, which is usually the case. Dot 3 absorbs moisture at a slower rate than DOT 4.
But frozen brake fluid isn't the OP problem; frozen water between the caliper and the brake pad is what he believes to be the problem and that is a reasonable conclusion.

[compu_85]

Gen2 W126s use DOT4, older benzes probably do as well. The manual calls for a brake fluid change every spring.

-Jasno

[LandYaghtLover]

Well since I have green coolant, there is no telling whats in there. And with ABS there may not be a practical way to flush whatever is in there and clean it out 100%. So is DOT3 and DOT4 mixable? I forget. I have a case of DOT 3 on hand already anyway.

But yes, I still think that is may just be a frozen water issues right now. And maybe it will not happen again. I sure hope not. But bringing up the fluid does remind me that I do now know when it was changed, so I will also do that.

[Hit Man X]

It just flushes right on through, no big deal. Scoop up a Motive Power Bleeder to make life easy.

Your car calls for DOT 4, use it

[mespe]

could be a stuck caliper. Which tire got hot? And it is unlikey that the brake froze with water, as braking produces heat, which would melt any ice buildup in the caliper.

[mespe]

Originally Posted by Hit Man X

It just flushes right on through, no big deal. Scoop up a Motive Power Bleeder to make life easy.

Your car calls for DOT 4, use it

A check valve, some clear hose and a plastic spice container make a one man bleeder. If you want to do an entire line use a bigger jar, but the jar has to hold vacuum.

[babymog]

An internally swollen or collapsed rubber line can cause similar symptoms.

[LUVMBDiesels]

Originally Posted by mespe

A check valve, some clear hose and a plastic spice container make a one man bleeder. If you want to do an entire line use a bigger jar, but the jar has to hold vacuum.

Or just fill the jar with brake fluid until the hose is well under the fluid level

[compu_85]

Originally Posted by babymog

An internally swollen or collapsed rubber line can cause similar symptoms.

Which brings up a good point: The flexible lines are 20 years old. Replace them.

-J

[Hit Man X]

Originally Posted by mespe

A check valve, some clear hose and a plastic spice container make a one man bleeder. If you want to do an entire line use a bigger jar, but the jar has to hold vacuum.

Ever used the pressure bleeder? For $50 it is a 'must have' along with a Mity Vac.

[compu_85]

2x on the power bleeder. Way better then vacuum bleeding.. you don't get air sucked in around the bleed screw giving you false bubbles.

-J