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  #17  
Old February 15th 18, 08:50 PM posted to alt.home.repair,rec.autos.tech,ca.driving
ultred ragnusen
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Posts: 54
Default Vibration at 50 to 60 mph coasting in neutral after rear brake shoes

wrote:

> When I was teaching the trade I would have had a brake unit in front
> of me, and you face to face - which would make the "understanding" a
> whole lot easier.


I agree with you that it must work the way you say, mechanically, but my
brain is having trouble visualizing how all the pieces work together in
that I know only how the pieces fit together, but I can't "touch" them and
"push" them and "wiggle" them in my brain to see how they affect each other
in real life.
http://i.cubeupload.com/Ktc8zF.jpg

> Next time you have a drum off, pull the emergency on part way and
> then lookat what has happened to the position of the shoes. Check
> closely before and after. then picture what would happen if the front
> shoe was "picked up" by the drum and consider the e-brake cable to be
> a spring. You'll get the picture.


Thanks for that explanation which is hard to write because you're
describing a moving system with springs and interactions.

The key I learned is that the star adjustment step just can't be skipped!

To try to give back to the group for the kind help, here is the tool I made
to make it easier to hold back the locking plate off the star adjuster. The
wire came out of a hot water heater I took apart to see how it works
inside, and it's about 6 to 8 inches long, where the critical part is the
painted area that starts 1-3/8" from the end, and is 3/8" long, which I
filed down to make an indent (since the whiteout paint wouldn't likely last
long).
http://i.cubeupload.com/LzvBps.jpg

The tool is to push away the plate which locks the star wheel he
http://i.cubeupload.com/Mgwt06.jpg

This is all you see from behind, if your head was as thin as a cellphone:
http://i.cubeupload.com/IQdwAl.jpg

The tool needs to go in deeper than a noob like me would think it needs to:
http://i.cubeupload.com/GuF7mL.jpg

Once it touches the plate, you need to push another 3/8" inward:
http://i.cubeupload.com/Hu4wpu.jpg

Then you have to hold it in that position while you get a chisel:
http://i.cubeupload.com/ALZOLp.jpg

This is what it looks like from the other side when its in position:
http://i.cubeupload.com/RyDEnN.jpg

You will have measured the drum diameter already at around 11-1/2 inches:
http://i.cubeupload.com/LMSp4y.jpg

You adjust shoes until they are 1/2mm (20 thousandths) less than drums:
http://i.cubeupload.com/RhPoYX.jpg
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