Frozen brakes!

[snapped_bolt]

Ha!

The wagon has been waiting for attention for about a year. When I fired it up a few months ago, it didn't want to move.
Last week in a freak break in the weather got me back out there. Waited on the glow plugs, and it started like it had been run 10 minutes previous. After about 15 minutes of warm up, I decided to put the car in reverse. I was alert for the most minuscule hint that the transmission was doing something more than adding weight to the car; change in idle speed, anything. After about 1/2 dozen shifter selections, I noticed the faintest rise when I put it in reverse. I grinned. I moved the shifter to "D". The car moved ever so not so much.
After a few more cycles the car began to free up. The rustiest wheel was the driver's side front- the car raised up like I was running over a block. It is now free.
I considered a lot of things I could have squirted on the rotor to spped up the process. The only thing I could think of would be 70 or 91% rubbing alcohol to act as an "evaporating lubricant". Any lubricant leaving a lubricating residue would not work!

Any one else try this?

Cheers!

snapped_bolt

[Can't Know]

I would not. Alcohol isn't going to act as a solvent for the oxidation (assuming that's what the problem is) and it may only worsen the problem by allowing the surface gunk to settle more deeply into the pads.

Letting a car sit for extended periods is never a good idea, particularly an old one.

Rather...I would pull each wheel, one at a time, and remove the pads. Put a thin block of wood in front of each piston (all of them on the given corner, not just one at a time, to prevent them blowing out) and have a helper press the brake pedal gently. See if the pistons move out FREELY. Then prise them back into place, all the way back in to be sure they retract FREELY (personally, I'd crack the bleeder screw before pushing them back in so the degraded fluid in the caliper doesn't press back up the line; you can bleed the caliper immediately thereafter once you reinstall the pads after cleaning them up). Next, lightly scuff the rotor faces with some emery cloth. Finally, take a piece of emery cloth and lay it rough side up on a flat surface and make several passed over it with each pad to clean off the surface gunk.

Repeat on each wheel. If any pistons do not move freely, you need to rebuild that caliper.

Good luck.

[cfh]

I experienced seized brakes 2x this year (2 different cars - 80 CD and 83 SD) - never ever happened beefore. On cars this old it is time to renew the flexible brake lines and the rebuild the calipers and possibly put on new front rotors (also re-packing or renewing the the bearings). I'm in the middle of all that now with the 80 model - gonna do rear wheel bearings too since one of the rear disks got so hot I no longer trust the grease.

Bleeding brakes when you've had the pistons out of the calipers is a whole new experience - on my 3rd quart of brake fluid and still not done. Cut some old lines from a junk car to "bench bleed" the master (take out the original lines from the mc; screw the "bench bleed" lines in their place; run them back into the reservoir, rather than a jar, and pump away). ) - I was stuck before I did that; making progress now.

[Can't Know]

^^^There really is no substitute for a pressure bleeder.

[snapped_bolt]

That was the last thing I did. The master cylinder was replaced and the brakes bled. The calipers were replaced in 2011.
The idea of the alcohol was to temporarily lubricate as the wheel moves. The alcohol would evaporate rather than leave a lubricating film. The rust would be removed from the rotors and suspended away from the rotor surface. Subsequent heating and applying/releasing the brakes should finish the job.
The car has sat on concrete all this time. But being on the north side of the house doesn't help with the moisture.
I think I'll try the 91% this weekend.

Cheers,

snapped_bolt

[Skippy]

Originally Posted by Can't Know

^^^There really is no substitute for a pressure bleeder.

A vacuum bleeder can make an acceptable substitute if you're careful about making sure you're still drawing vacuum as you close the bleed screw. I've even bled a clutch with it a time or two, though I was really wishing for a pressure bleeder with that job.

As for the OP, I don't think alcohol lubricates to any meaningful degree.

[Can't Know]

Originally Posted by Skippy

A vacuum bleeder can make an acceptable substitute if you're careful about making sure you're still drawing vacuum as you close the bleed screw. I've even bled a clutch with it a time or two, though I was really wishing for a pressure bleeder with that job.

As for the OP, I don't think alcohol lubricates to any meaningful degree.

True, though on newer model cars with ABS and BAS a vacuum bleeder is next to useless.

[Graham]

Originally Posted by snapped_bolt

The idea of the alcohol was to temporarily lubricate as the wheel moves. The alcohol would evaporate rather than leave a lubricating film. The rust would be removed from the rotors and suspended away from the rotor surface.

You could probably just use water in a spray bottle. I usually give the car a push just to see if wheels are free. Usually doesn't take much.

One of the problems I have had after storage, is that the pads can react with the rotors causing an 'imprint'. This can cause the rotors to be quite pitted and bubbled. When you drive the car, the rotors can become grooved.

I have had this happen several times over the years (300D below). Only solution would have been to remove the pads during storage, but with 3 cars stored, that is a lot of work But so is replacing them

[snapped_bolt]

The idea of alcohol as a lubricant is the same as water-just to suspend the rust particles as they are "peeled" off the rotor. The alcohol will evaporate quickly, and not soak into the pads, re-freezing to the rotors. At this point I am not looking to drive the car as I am waiting for a response from Biodiesel300TD on his SLS repair kits since the car is in the same position as a racing speed boat-the "bow" is high in the air. I would like to keep the rust from fossilizing in place until the repairs can be made. Otherwise, I would squirt on the alcohol and drive around the neighborhood and wear off the rust.
I surely hope the rotors don't end up deeply pitted as all four rotors were replaced along with the calipers and hoses 3 years ago. If they are and develop grooving I'll just have to do them again.


Cheers,

snapped_bolt