So, I was helping (okay, trying to help is more like it) a local (Patti)
get a 64 1500 back on the road, by doing a round of brake inspection and
bleeding, and ran across a most peculiar thing, that maybe someone has
seen before. But first here are some notes:
1. I thought there were no shoe adjusters in the front, but looking at
the pristine, 44 year old manual, (what a cool resource!) it turns out
there are, they are just "away" from the wheel cylinder locations.
2. funny how no matter what wheel you choose to start, the one with the
problem will always be the last one looked at, 20 minutes before you
have to leave. I'd bet Confucious has some sort of philosophical words
for this kind of luck.
So, my findings.
Inspection:
A. all clean, dry and ready to go (drums recently turned, shoes brand
new) except for right-front, lower shoe. All return springs very tight,
in good shape.
B. There are two countersunk screws, offset from the studs of course,
that hold the drums onto the axle, presumably so that when changing the
tire the drum doesn't come off, although I noticed that when bleeding,
the shoes moved the drum, so that could be another reason, so it is
probably better to replace (and anti-sieze) these if all the reasons
are not know. Anyone know what thread size this is? (like 1/4
diameter, 1/4" depth, I hate holes like this, because there is so few
threads, it is easy to get it wrong and cross-thread it before you
figure it out)
C. There are pins with a flattened end that have a spring loaded twist
washer locked to the end - located 1/2 way along the front shoes, to
keep the shoes attached to the backing plate. (none on the rear, and no
hole for them, this was curious to me, VW's have these all around)
My question: they are very, very loose, like the stud is too long. Is
this meant to be, or has someone swapped out VW studs? I see no evidence
of the shoes riding out against the drums, but, like I said, this car
has not driven in quite a while, and never with these all-new brake
parts.
2. leaky wheel cylinder on right-front. It had leaked inside, onto the
shoe, so it didn't seem like a line connection leak. So little fluid
was on it, I'd be tempted to soak it in solvent and dry it out, but
probably better to buy one set and replace the one shoe.
Much like the front disks (and different than my aircooled VW
experiences), there are two wheel cylinders, one with the line input and
an output, and one that is the termination-with only an input. This is
the one that is leaking. They look cleaned and relatively new, so maybe
a seal kit would work for this?
2A. The owner said that it took a massive sized person to get the shoes
on and the springs back in place. My experience with the VW system
(which the return springs go shoe-to-shoe, the Datsun rears go
shoe-to-shoe and the fronts go shoe-to-hub!) was that you put the shoe
ends as close to their grooves in the wheel cyls as possible and rotated
them OUT towards the axle end, then attached the springs, then rotated
the shoe into its home. Does this work? Is there some other trick on
the shoe-to-hub models, or are you left truing to stretch the VERY STOUT
return spring with assorted crude "brake tools" available at local Pep
Boyz?
3. we bled the whole system, system is clear of all large bubbles,
although the last wheel (the perpetrator R-F) had a seeming endless
amount of carbonation-sized bubbles coming out of it. And, the pedal
still goes to the floor. The owner has installed a master cylinder
re-seal kit, recently. Possibly one of the seals is reversed? (as well
as the obvious problem listed in #2 above)
Now, here is what happens.
-Press pedal to floor, some resistance, but no stoppage short of floor.
-Press it quickly again, goes to floor with no resistance. (piston in
master has not retracted, now are just pushing pedal actuator rod up
against piston)
-Jiggle the pedal with your foot, barely touching the rod-to-piston: you
can feel the piston slowly creep back up the bore, until it is at the
"top" again.
So, from #3, I was thinking a seal in the master cylinder is backwards,
letting fluid flow past, with a minimal amount pumping fluid out while
one of the lines is open.
Fergus O, 69 2000, HB, CA
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