Cannot disengage parking brake!

Posted by: @nottamiata

Any ideas, critiques?

 

Yes it won't work.  The cable is in a teflon or teflon like tube that is very tight to the cable. If you were to dissect the cable you will see the layers.  When I inspected my old cable because I was curious of what jamming it, it turned out to be the white tube that disintegrated  on its self and restricted the cable movement to about an inch.  

There was some guy long ago that injected antifreeze in the hopes of not letting the cable freeze from the water in it. I don't know how that turned out. 

In all the excitement over being able to drive again, I realized two things:

1- Maybe I shouldn't be driving it, DUH.

2- If the caliper was seized, is there even a small likelihood that it would be able to un-seize, like yesterday and today, then re-seize, like hopefully not today?  Or, does this un-seize behavior point more toward a failing/sticky cable, or still not conclusive?

Feel pretty damn stupid right now for driving it today, LOL. I am taking him home in a few minutes.

I found a caliper rebuild post over on MR2ROC, I think I could level up again if I complete that. Lots of little parts, but that's a good tutorial. Could level up by just replacing the calipers, but thats kinda ouchy... cheaper than a "brake fire", though. Still have no evidence about the calipers either way. And it might have just been ice. The article did mention water infiltration in the cable, so thats apparently a thing.

Hope I make it home, there was no sign of brake burn or any drag on the way to work.

Posted by: @nottamiata

In all the excitement over being able to drive again, I realized two things:

1- Maybe I shouldn't be driving it, DUH.

2- If the caliper was seized, is there even a small likelihood that it would be able to un-seize, like yesterday and today, then re-seize, like hopefully not today?  Or, does this un-seize behavior point more toward a failing/sticky cable, or still not conclusive?

Feel pretty damn stupid right now for driving it today, LOL. I am taking him home in a few minutes.

I found a caliper rebuild post over on MR2ROC, I think I could level up again if I complete that. Lots of little parts, but that's a good tutorial. Could level up by just replacing the calipers, but thats kinda ouchy... cheaper than a "brake fire", though. Still have no evidence about the calipers either way. And it might have just been ice. The article did mention water infiltration in the cable, so thats apparently a thing.

Hope I make it home, there was no sign of brake burn or any drag on the way to work.

   If you park on a level surface I would keep it in gear to hold the car until it can be diagnosed and fixed.  In my garage I do not use the parking brake just for this reason of preserving the cables.     

  Because weather seems to be a factor its most likely one of the cables and most probably not both.  They are both joined and if one is bad it will effect the other in how it functions when you run out of travel or if one sticks.  

If its the caliper I  wouldn't rebuild  because they have a possibility of leaking afterwards. I also wouldn't buy a remanufactured caliper because they are known to pack them with grease that leaches into the brake fluid and they can make the pedal feel weird. I would be looking for a good used low millage from salvage. Its possible that the same caliper is used on the Toyota Echo so your choices might be broadened.  

@dev

Good to know about the leaks. My gut reaction was not to do that. Even without that, it is likely not a great idea to dis- and re- assemble MY FREAKING BRAKES, (plus, its the rear to boot!) at my lowly Level 3.

With no evidence at all, it does seem like a caliper seizure is a one-way deal.

OTOH, I once had a speedo cable, obviously long ago, that seized, got graphite lubed under warranty service (sigh), seized and lubed AGAIN (cheap a-holes refused to replace it until the warranty ran out -- it was not a Toyota). The point being that cables may un-seize. The cable worked for about a year after each service was done, IIRC.

I dont mind replacing the cables, and I hope that they are the issue, not the calipers. Not freaking out about the job, just the stupid timing. Already have a project going, and it's COLD outside. Waaaaaaah.

 Actually I would hope it was the calipers because its a much easier job in terms of replacement.  Im my foolishness of trying to downsize parts I had a good used set of rear calipers that I was keeping for a rainy day and let them go to a member for a good price. 

A sticking caliper can free its self.  I had one on my Honda that burned though the pad and once I replaced the pad and pushed the piston in it was working fine for about six months until it burned though the pad again.  Nothing in auto mechanics is definitive as there are a lot of unknowns and that is why diagnoses on the internet without getting dirty will have mixed results. 

 This is one of the biggest problems on Spyderchat with people throwing up guess that leads to a costly shotgun approach to fixing issues that were found to be a simple fix.  

My rear caliper seized, never unseized. I disconnected the parking brake and the caliper shot open. Ended up removing the cable and it was FIRMLY stuck half engaged.

@cyclehead

Hmmm. I'll take your word for it, but there's something about your explanation that doesn't fit my narrative. 

Perhaps the internal cable sheathing or coating breaks down or the mystery lubricant no longer lubricates... I dunno. I just figured that cracks in the casing lead to rust and failure to flex which will lock it in the on position. One thing I did not include in parking deck story is that I used a rock to gently whack the brake 'lever' at the brake end into submission. 

After years of back yard wrenching on a budget with half an idea of how things worked, I have learned that short cuts are very rarely shorter. The cables are pretty straight forward to replace. Yes it's a pain, but it's not clutch replacement, it's simple grunt work  that takes more time than you think it should. I did mine surprisingly fast but my car is thankfully very clean underneath and I spend half my time cleaning bolts and scuffing/painting/greasing things so that next time it's easier.

Posted by: @nottamiata

It was about 25F this morning, and was very cold overnight. So, Guess #1 has something to do with water infiltration and subsequent freezing. However, I admit that I have zero mental imagery of the actual brake mechanics, so I dont even know if this is a possibility. Going by the sudden onset and environmental clues there.

The parking brake cables collect water.  When the ambient temperature falls below freezing, the cables seize.

The only sure cure is to replace the cables.  Driving with a seized parking brake cable can result in expensive damage.

A stop-gap solution is to leave the parking brake OFF and use wheel chocks to keep the car from rolling away.

Yeah I agree with cyclehead's synopsis. My car doesn't see freezing temperatures. And yet the handbrake cable seized. Once pulled out, I tried pulling it with all my strength and it wouldn't budge. Most likely it's stuck due to the coating or sheathing disintegrating. 

It’s not unusual to have multiple causes for the same resulting problem. In some ways cars are like humans with different tendencies.

Thanks all. This all makes sense. Unfortunately, it doesn't help me decide whether to order new calipers or new cables. This is in no way a lack of gratitude for all the insight.

Honestly, I am totally vapor-locking on this one, in terms of planning a fix. Unless I can get it to freeze or seize again, it could be "anything". I also realize that driving with the brakes on could wreck virtually the whole wheel, or far worse cause bodily harm to someone.

The day after this happened, it was 23F again in the morning, and all worked fine. Aside from things just being random (The Frog apparently loves keeping me in a constant state of worry and paranoia), the thin clues say I got water in cable, it froze, then it melted the next day and also drained away. Poof, no more problem, until the next puddle-freeze cycle.

But, without something being seized, I have nothing to work with. It all works fine right now. But, do I want to just drive it around? Ehhhh, no! Not if one tap on the brakes at 70MPH could seize a caliper (just one, of course, because that's the most lethal thing it could do).

Oh, and my driveway is slanted, so without Ebrake, I cannot park long enuf to chock it. I guess I could drive the front wheels over a 2x4 and hop out and chock real quick, but that sounds like a Darwin Award process.

I could just go ahead and pray, do the cables and see, but this does nothing for me if it is a caliper. I regret trying it again later when it warmed up, but even if I hadn't, it STILL would have been inconclusive if ice were the cause (root cause would be leaky cable, water and cold are contributing factors), because it would just work when above freezing.

So waaaaaah. Again. I am totally vapor-locked. Buh-dee-buh-dee-buh-dee-buh-dee...

Meanwhile, he is just parked there and chocked. And we're both sad.

If it's un-seizing, then I'd spray some WD-40 into the sheath and keep driving for a while.

i second the Water Displacement formula No. 40 suggestion.

and maybe put something like white lithium grease (WD40 as a brand makes it as well) in as well.

Excellent. I shall try this, and I have some of each, although The 40 has been restricted to coming no closer than 10 feet from His Frogness. Might have to make an exception <shudder>.

I will also avoid the highway during this hopeful recovery, keep it to the 35 zones. I have no fantasy that it is going away, though. But, then, there is that chance that it might. In my experience, problems sometimes go dormant, but its rarely permanent. I can hope.

I don't use my parking brake much if at all any more.  Cold weather freezes it, and I'm not risking it again.