I'll add this to Tom's sage advice. It seems many of the brake shoes on the
market now are made a bit oversize (I think they are still made based on
dimensions from back when it was SOP to "arc" the shoes to fit the drum or
something). Even on drums out near their max oversize there have been instances
where the drums just would not go over the shoes even with everything setup
right and the adjusters turned all the way out. On several cars I worked on at
CDM we had to back off a *lot* on the hand brake adjuster, and on several we had
to completely disconnect the handbrake clevis on one side just to get the drums
on. On all of the cars we were able to eventually get the shoes centered
(something else to look out for) and the handbrake connected and adjusted.
Usually in those cases though, the handbrake bellcrank on the axle ended up
positioned a bit "over center" according to Les, which indicated to me that the
shoes were larger than OEM shoes. On several cars the handbrake was adjusted
full loose and the shoes were still dragging a bit. In those cases we either had
the shoes arced if the fit was very bad (hard to find a place that will or can
do that anymore), "tweaked" the arc by hand, or, if it was just a small fit
problem, just took the car out and drove it hard to bed the shoes to the drums
and then did an readjustment. Almost always in these cases, a follow-up brake
adjustment was needed much sooner than one would have expected as if the lining
wear was accelerated or not uniform on the full surface of the lining. If you
looked at the wear pattern on the shoes, it was almost always a case of the arc
of the shoes not matching the arc of the drum, which is why I think they are
making shoes based on the old dimensions when arcing shoes was SOP. But I will
say in some cases the arc of the shoes seemed very close to the drums and the
drums still fit very tightly, almost as if they used a thicker lining than spec.
I think most often this was on comp relined pads, but not always. A quick basic
check of shoe arc is easy, put a shoe in a drum that is ready to go (has been
turned etc.) and see if you can rock the shoe end-to-end, If so the shoe arc is
smaller than the drum, and only the center of the lining will be working to stop
the car until the shoe has bedded in to the drum. If the shoe won't rock
end-to-end, then see if you can fit a feeler gauge between the drum and the shoe
near the center of the shoe while you are holding the shoe tight against the
drum. If you can, then the shoe has a larger arc than the drum and only the ends
of the lining will be working to stop the car...etc.
Thomas Walter wrote:
>
> Jeff,
>
> Two words: BRAKE ADJUSTERS!
>
> Up at the top of the brake backing plate is an adjuster.
> There are two little pistons that will push out from the
> center portion when it is screwed in. To move it in or out
> you need to turn the 1/4" squared off shaft on the back.
>
> On thing I always do, first time I am redoing the rear brakes,
> is to remove the adjuster. Two nuts come off, WHACK IT with a good
> rubber or rawhide mallet to get it to break loose. Once off,
> soak in good parts cleaner or what ever you have to clean it up.
> Careful the pistons don't fall out (they might, but usually are
> so junked up they won't move). Paper towels and even WD-40 help
> in getting it cleaned up. Get a big adjustable wrench on that
> square adjusting post and start trying to move it back and forth.
> Steel threads in an aluminum body mean corrosion and a pain.
> Working it back and forth little by little helps until you can
> get it fully apart (takes a while!!!). Once the threaded bolt is
> out, you'll see how the thing works. Clean everything up really
> good, and if the 1/4" adjusting post is chewed up, clean it up
> with a file just enough so the back end of a 1/4" socket slips
> over it. Once that is done, smear a light coat of anti-sieze on
> the parts and screw everything back together. Also notice the
> piston really on fits in one way. Hold the pistons together with
> a rubber band until you bolt the thing back in place.
>
> Now to adjust the brakes I keep around a piece of 10 mm hex that
> I cut off an allen wrench. Using it, and two 10 mm sockets on both
> sides, and slipping the whole thing into a piece of tubing... one
> end fits the adjuster and the other my 1/4" adjusting tool. Viola
> neat tool for adjusting the brakes.
>
> "loosen" the adjuster all the way down, and the shoes move back in.
> Slide on the brake drum. Now "tighten" the adjusted (close wise
> looking at the end of it) and you'll notice it will adjust in 1/4
> turns. I spin the drum, tighten. Keep repeating until you get it
> to the point where the drum is too tight to rotate freely. Now
> back off the adjust 1/2 to 3/4 of a turn. Easier to feel this
> free or dragging action with the wheel in place, but gives you
> an idea of the adjustment needed. When I am done, I smear a little
> more antisieze over the threads and place a small piece of 1/4"
> tubing over the exposed threads to keep the corrosion off them.
>
> One way to check to see if you need a brake adjustment: step on
> the brake pedal. Notice how far down it travels. Pull up on the
> hand brake, and repeat. If their is a noticeable difference: time
> to adjust the brakes!
>
> Cheers,
>
> Tom Walter
> Austin, TX
>
> Jeff Etheridge wrote:
>
> > Just installed new shoes on my 1600, now i am having a hard time getting
> > the drums back on! This is my first venture doing drum brakes...any
> > tricks to doing it? I didn't turn the drums but did clean them with a
> > wire brush and a pneumatic grinder, then buffed them with a pad...
> >
> > Jeff
> >
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--
Marc Sayer
82 280ZXT
71 510 2.5 Trans Am vintage racer
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