Parking brake caused wheel to jam.

budwich

Original poster
Member
Jun 16, 2013
2,027
kanata
So off to do some camping before the weekend rush. First of the camping year issues but that's another story / forum.
Anyways, at the camp site, jumped into the TB, go to pull away to go to the store, vehicle moves about 3 feet and stops cold. Brake pedal wasn't being touched, neither was the park brake used. I could back up and I couldn't move forward more than a few feet.... rear left wheel lock. After much head scratching and checking, lifted both wheels off the ground, right spins by hand... great... don't hear anything unusual in the rear end. Left side won't budge... :-(

After some swearing at various bolts along with trying to pull the wheel hub, finally get the hub off and "plop", the park brake falls on the ground. There is something like a "horseshoe" like semi circle with two shoes... one had unbonded, I guess and was jamming into inner rim / hub and locking the wheel solidly.

Glad it didn't lockup while travelling down the road. I guess the real question to the story is... what holds this thing in place. I am use to seeing some sort of spring assembly in the "traditional shoe fashion" (at least on the ford EX I had). I saw no springs and I don't even see any bolts. The "activation level" is still attached to the cable but that it. I will likely have to take off the other side to see what up but was wondering if the group has any comments / directions especially on the parts needed to return the things to operational.
 

Mooseman

Moderator
Dec 4, 2011
25,257
Ottawa, ON
There is a spring clip at the bottom (3) and the "spreaders" (or the mechanical wheel cylinder) that the ends go into at #1. That's it.

2010-12-02_184200_ebrake_shoes.gif


The shoe material became unbonded from the shoe. Just replace the shoes and possibly the clip, adjust and done.
 
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Reprise

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Jul 22, 2015
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I was running around with a loose shoe for a long time before replacing them recently as part of a brake job. Being recent, I remember this well; you may find the following helpful...

In my case, the loose one didn't seize; it just went clangety-clangety-clangety when reversing 'cold'. Annoying & embarrassing.
My shoe on that side had fully delaminated - wasn't a trace of the friction material to be found.

Anyway, part #s 1 and 3 above will come as part of an e-brake h/w kit - for whatever reason, new e-brake shoes don't come with new h/w by default.
I got the shoes and the h/w kit at the local shop ('duralast', so whichever one that is). About $10 for the kit; enough to do both sides.
Note - The h/w kit may contain two different holddown clips / screws; ours uses the smaller of the two. So don't worry about any 'extra' pieces.
If needed, line up the new parts with what you remove. Helped me out to do so.

R&R:
Remove the holddown clip & bolt if still screwed into the backing plate (10mm, and a deep socket definitely helps here; maybe even with a short extension, as well as a universal joint adapter. 1/4" drive is the way to go, if you have the proper sockets.)

After the shoe is out, examine the spreader. Your kit will contain 3 components for a new one, hopefully along w/ some white lithium grease.
Remove the old spreader (the two halves are threaded internally, so 'unscrew' it), clean the backing plate area with your favorite brand of brake cleaner, pack the two halves of the spreader with the grease, and don't forget to insert the small rod (same on both ends; no 'wrong way' to put it in, even if you find 'flattened' areas running the length of the pin). The rod should fit inside the round hole on the adjuster lever (which connects to the e-brake cable.

With the spreader assembly in place, screw the two halves together 'inward' (like a conventional bolt / nut; RH side clockwise) until it seats. Make sure the slots on the outer edges are lined up more or less vertically; adjust back outward as needed to get a rough alignment. This is what the 'tabs' on the shoe will fit into.

Insert the shoe. Many people complain about how the shoe doesn't fit around the hub, but I really had no trouble at all with removing / installing. IIRC, the 'open' end of the shoe will fit around the inner axle, but it's tricky / tight. I didn't even have to do this - just angle / maneuver the shoe a little and it should more or less 'fall in' past / around the outer hub.

When seated properly, the inner edge of the shoe should rest against the backing plate; there are molded areas that conform to the inner edge of the shoe.
With the shoe tabs in the spreader 'slots', take a flat blade screwdriver and turn the gear 'up' (CCW) until the two halves spread and hold the shoe in place. Not super tight just yet; a tiny bit of slack / movement is OK (makes the next step easier.)

Take the new screw and holddown clip, and fasten it down so that it catches the inner lip of the shoe. This is probably the toughest part of the whole job. Alternately, you can put the clip in *before* the shoe (easy access), but then it's really tough to fit the shoe in properly. The 'right' way is shoe followed by clip (inverse of removal). But whatever works best for you. The clip lines up properly one way, although it looks like it could 'fit' both inverted *and* reversed.

After you get the clip in, and re-checking your shoe tabs on the adjuster, snug the holddown clip tight. There is a torque spec; I didn't bother breaking out the 1/4" wrench for it. Obviously, if you gorilla the screw, it'll break off.

The 'proper' pre-adjustment for the spreader assembly will allow you to put the rotor back on with a slight drag. I can't tell you how 'much' to widen / narrow the wheel; it'll probably be a trial / error exercise. (shhh...don't tell anyone, but I didn't spend a lot of time on this, since there's an automatic adjuster that operates when you drive in reverse, and I haven't had any problems - but I use my e-brake every time I park, too)

And with that, you're done. It should take just slightly longer to *do* all of this, as it did to *read* through it... :laugh:

If you really want to get 'anal' about it...the 'shield' around the backing plate will probably be corroded; perhaps coming off in your hands. Mine was. Replacements are fairly cheap, but IIRC, they're a chore to R&R. I just removed the really bad portions that were crumbling away, by hand.
 
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budwich

Original poster
Member
Jun 16, 2013
2,027
kanata
thanks for the great info and advice... certainly looks a lot easier than the "spring and lever adjust" system of the regular "shoe design" and that setup in the old ford ex which was difficult to get back together and into the interior hub. The old TB needs a few other things (especially the exhaust manifold work) so my fingers / hands are already "burning" from the scrapes and scratches.... :smile:
 

Mooseman

Moderator
Dec 4, 2011
25,257
Ottawa, ON
(shhh...don't tell anyone, but I didn't spend a lot of time on this, since there's an automatic adjuster that operates when you drive in reverse, and I haven't had any problems - but I use my e-brake every time I park, too)

That is actually incorrect. The automatic adjuster is in the lever mechanism and all it does is take up cable slack. You must adjust the shoes to get a slight drag on the rotor/drum. There is no automatic adjusting lever on the star wheel that does this like on regular car drum brakes.

It's not a bad idea to wire brush the drum to remove the rust that likely accumulated from non-use. Clean with brake cleaner.

Just a note on the orientation of the shoes. On cars with drum brakes, I had a little phrase that helped me remember which way the short shoe would go. "Short shoe forward". If you put them backwards, you knew with the brakes locking up. On these parking brakes, you want one to lock in one direction and the other in the other direction. I once saw on a stock setup that one side had the short shoe forward and the other it was towards the back. This makes sense as you want it to be able to lock the vehicle in both directions. I don't remember which side was short shoe forward.

After installing, it's a good idea to do a couple of rolling stops in a safe area using the parking brake, forward and reverse, just to bed in the shoes to the drums.

Edit: https://gmtnation.com/forums/threads/handbrake-issue.924/

Edit 2: FAQ: Brakes
 
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Realism

Member
Nov 25, 2015
179
Idaho
While you're doing this, it's also a good time to check your view-able parking brake line for any nicks or cracks that expose any cable at all, pretty easy to get a lock up that way as well, bout the only thing you can do at that point is cut the cable and replace. Someone from here on the old site was telling me that the parking brake cables with these has higher chance of cracking and causing the cable to seize. IIRC it had something to do with the earlier years and poor selection for cable covering.
 

budwich

Original poster
Member
Jun 16, 2013
2,027
kanata
yep... check the operation, end to end, while each side was apart. Everything seemed to move fine. One thing that was bothersome was the degree of adjustment. Even thought "spinner / adjustment cell" is fully spun closed and its length is as narrow as physically possible (end to end... no spacing, fully detracted), putting the drum on still required quite a bit of wiggling. Hopefully, they are not binding more than they should once a few runs happen. I cleaned the drum edges to help but it didn't do much. Shoe pads seemed to be about twice as thick as the old.
 

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