Brake Locking Up

fotorunner

New member
2000 4Runner SR5. I’m having issues with the driver’s side rear brake locking up. I’ll come to a stop and you can feel that brake suddenly just lock so far always when I’m about at a stop and doesn’t happen if I slow down slowly.

On dry pavement when I start up there’s enough friction between tire and pavement to make it rotate, on ice or snow, I’m screwed. However if I back up, just a little, it will unlock. (at least so far)

I’ve had it in the shop twice. First time they took both rear drums off and cleaned and checked everything and then readjusted the brakes. They worked for maybe a day. Then the driver’s side started locking up again. It was icy out and a real pain in the butt.

Today I took it back, they figured there had to be something broken in there it apart, cleaned it, found nothing broken or missing, both brake shoes look good. The drivers side seal is just showing the very slightest trace of oil seepage but it’s basically just a little ring of dust around the seal, no oil in the drum. Ended up taking both drums off and readjusted the brakes again. I drove it around town for 2 hours starting and stopping, I thought it still felt weird but it didn’t lock up.

Came back home let it set out for awhile and when I got it and moved it the brake locked up. Back to square one.

It has been extremely cold here and it seems like that makes the situation worse, of course I might imagine that too.

Dealer shop and they haven’t charged me anything, I think they’re at a loss too. Would appreciate some thoughts from you guys.
 
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Sounds like the rear inner axle seal. They are notorious for leaking on these rigs.

Not if that oil hasn't gotten to the shoes or drums like the OP said.

Maybe sticky rear wheel cylinder? Weak return spring? Backing plate where shoe contacts scarred and keeping shoe extended?
 
Brakes Locking Up

A quick question for ya, is your Runner a 5 speed or do you use the parking brake often? I know that in the extreme cold, the cable that runs the rear parking break can tend to stick or refuse to move properly, it has happened to me before, especially when parked outside overnight. If your cable is sticking it could be holding that brake locked on the right side.
 
I had that happen to me on my old rig. Try ajusting the ebrake cable tension on the rear axle. If I remember correctly one side was way out.
 
Not if that oil hasn't gotten to the shoes or drums like the OP said.

Maybe sticky rear wheel cylinder? Weak return spring? Backing plate where shoe contacts scarred and keeping shoe extended?

Good point, must've missed that as I was scimming through it. Everything you mentioned seems like prime candidates to look at, in addition to the ebrake assembly freezing if the OP uses it overnight and its cold the next morning so it doesn't release by itself.
 
Mine does it the first few stops in the morning. Passenger rear. I suspect it's a sticky wheel cylinder.
 
Thanks for the replies.

It's an auto. 206000 miles.

I don't often use the ebrake.

I sent an email to a mechanic friend of mine in Denver as well as a couple of forums, we'll see what he thinks too. I'm suspecting a wheel cylinder problem myself.

Sometimes when it locks up there's a notable thud feeling in the brake petal. Nothing audible you can just tell, "crap it locked up again". Then resistance as you start out again.
 
Sometimes, the issue is aftermarket shoes. Some out there just don't work right. I can envision a scenario where those might be ok until it gets real cold, and then this happens.

So, if you have ruled out the logical suspects and the mystery persists, before you junk the truck, try OEM shoes on it.
 
Sometimes, the issue is aftermarket shoes. Some out there just don't work right. I can envision a scenario where those might be ok until it gets real cold, and then this happens.

So, if you have ruled out the logical suspects and the mystery persists, before you junk the truck, try OEM shoes on it.


Thanks,
It has the original shoes on it.... and they're still in good shape, at least looking at them.

Yes I've learned my lesson on OEM vs aftermarket with the front brakes. OEM lasted for 14 years and 170000 miles, aftermarket lasted 1 year and less than 20000. Buy once/cry once.
 
I'm resurrecting this post to update.

First of the guy who said seals nailed it. The dealership couldn't figure it out so in Feb when I was headed out of DIA for a week long trip I dropped it off with Jesse Myers at ATLR in Denver. He figured it out.

The seal was hardly leaking at all, but it was enough to sling tiny particles of oil all over the shoes and drum. I suppose partly because of the cold the brake would just glue itself until you broke it lose by moving the vehicle. The dealership would go in, clean things off and that would work for a hundred miles until enough oil was slung onto things to recreate the problem.

Jesse replaced seals on both sides and I had them do the brakes while they were at it. Problem has been gone since Feb.

Thanks for everyone's help with this. Hope this post helps someone else.
 

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