Parking brake question-engaged on it's own?

Issues with shocks/springs, tires, steering box, stopping, etc.
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rewind
Canada
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Joined: Wed Jan 23, 2008 12:23 pm
Location: Halifax, Nova Scotia

Parking brake question-engaged on it's own?

Post by rewind »

I was driving through town the other day when my truck started to bog right down, it felt like it was going to stall and I couldn't get any speed. I crawled into the nearest parking lot not sure what was wrong trying to keep it from stalling in the street. I had read the Transmission Failure thread a few days earlier and was thinking that might be a trans problem. The brake pedal felt fine, clutch pedal felt normal the engine idled fine with the clutch in, no strange noises. I went to pull the parking brake but the handle wouldn't budge and it did feel like the brakes were on. I drove through the lot slowly to find an empty area if I was going to be stuck there, when the problem just went away, the truck started to roll easily and I could pull the brake handle out engage the brake and release it fine. When I got home and testing the parking brake I wasn't getting as much throw on the brake handle as before but checking the forum it's about the amount it should be at the handle and at rear lever. My question is what could cause the parking brake to engage spontaneously if that's what happened? I've driven it since and haven't had any issues, the parking brake still holds strong and will stop the truck dead from a slow roll and release completely. I couldn't find a similar problem when I searched, hopefully it wasn't something serious but I'm not sure where to start since it's gone away.

Thanks, Shawn.
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4x4Pinz
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Location: arizona

Re: Parking brake question-engaged on it's own?

Post by 4x4Pinz »

there are a couple of scenarios that come to mind.
1st would be that when you last released the parking brake the cable did not fully allow the brake to release. I have had an instance where I release the Ebrake but not all the way, it took several miles on the freeway for the pads to heat up enough to drag to the point where I thought something was dragging the truck to a stop. The ebrake finally engaged fully making for an interesting stop at freeway speeds. Once disengaged everything returned to normal.

2nd scenario would be that a pad has come loose from the ebrake system and was jammed so that the system would not allow the brake to be engaged. As you pulled into the parking lot and fiddled with the brake cable the pad released allowing things to work as normal. The loose pad should still be in the system someplace and would require disassembly to verify.

In either case I would look until I found the culprit. Having the ebrake work when least expected is no fun.
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Jimm391730
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Re: Parking brake question-engaged on it's own?

Post by Jimm391730 »

On my first brake adjustment I must have had one of the wheels a little too tight; after a couple of miles into town one of the rears was dragging pretty good. Luckily, you can remove a wheel on a 712 and not quite have the drum on the ground, so I was able to creep in low range until the adjustment port in the drum lined up with the adjuster so I could get it released, but as it cooled the drag decreased. The hot drum allowed me to know which wheel was the culprit.

I've also had a brake shoe lining come loose from the shoe and bind up inside the drum (on another vehicle). The drag changed depending on the position of the loose lining. As 4x4pinz said, this might have occured in your parking brake.

And be sure the parking brake lever has the spring to hold it in the released position. If the spring is missing or weak the lever might have not returned fully.

But you can feel for heat to know which brake was dragging (on a wheel or parking brake). If it happens again this will help you to pinpoint the problem.
Jim M.
712W and 710M
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TechMOGogy
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Location: Ontario, Canada

Re: Parking brake question-engaged on it's own?

Post by TechMOGogy »

To test for heat I use one of these http://www.fluke.com/fluke/usen/thermom ... ?PID=56094
Works well for quick temps of portals, drums, tranny etc etc
There are a lot of manufactures and you can find them pretty cheap these days.
Plus I can use it for my smoker to monitor temp :)

Image
72 Pathfinder | 75 710M 2.7i | 96 350GDT Worker
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4x4Pinz
United States of America
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Joined: Sat Oct 24, 2009 6:17 pm
Location: arizona

Re: Parking brake question-engaged on it's own?

Post by 4x4Pinz »

also works well to help identify a cylinder that is not firing properly. just check the header tube coming from each cylinder. great product to have for all around the house. even find under floor leaks in water pipes with them :)
rewind
Canada
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Joined: Wed Jan 23, 2008 12:23 pm
Location: Halifax, Nova Scotia

Re: Parking brake question-engaged on it's own?

Post by rewind »

Thanks for the replies, I'll check the cable more closely to see if it's binding somewhere. It seemed odd that it engaged all of a sudden but I had probably been driving about 10min so maybe it had heated up and began to bind, it didn't feel like it was dragging before that but I'm not sure. I'll make a few short trips to check the temps on the drums as well. I just found a reference to a write up in the yahoo groups on dissasembling the parking brake with some pics and I have the manual, I'm not much of an experienced mechanic but I can usually follow the directions well, it just takes me 4 times as long. I'm due to adjust the brakes as soon as it warms up a bit more for some spring maintenance, so I'll check the parking brake then as well. The parking brake actually seems to work better now than before and if this hadn't happened I'd be really happy with the way it grabs.


Shawn.
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