94 Civic: handbrake failure on one side

I finally had an opportunity to investigate the handbrake problem I
raised some weeks ago. Not as simple as I would've hoped.

I've got rear disc brakes, so the handbrake cable attaches to the
"parking brake arm" as described in the service manual (p. 19-5). This
arm apparently attaches to a shaft that descends into the caliper and
activates the caliper piston when the handbrake is applied.

The problem is that the arm on the problem (left) wheel pulls all the
way around to the caliper pin stop without engaging the pads--it's like
it's disconnected from the shaft, or perhaps the shaft has sheared. On
the right it pulls merely 1/4" before the brake is engaged. Visibly,
everything appears to be in place on the left as on the right, though I
haven't yet removed the return spring and tried the parking nut that
attaches the arm to the shaft (didn't have the right tools with me. grrr.).

George MacD. suggested, among other things, that it could be a bad
self-adjusting piston, but I don't think that's the case here given that
applying the brakes with the foot pedal appears to properly apply the
brakes on the left wheel.

It'd be nice if it's just a loose nut, but somehow I doubt that. ;-(( Is
there anything I should know about that nut before I start working at
it? As in, how can one keep the shaft from turning while removing the
nut, for example? I'm worried that the shaft has sheared and I'll have
to replace it. Are there any tricks to replacing it--if it's even
possible to do so without specialized shop tools? I'll probably be able
to investigate the shaft in a week or so.

[BTW, anyone know which shaft is which--Shaft A and Shaft B are
described at the slhonda.com parts site. If I can judge from the image
number positions, "A" would correspond to the right side while "B" would
correspond to the left, but confirmation would be appreciated.]

Eleven bucks for a new shaft would be a hell of a lot better than $190
for the whole blasted caliper...

Thanks for any helpful input.

Abe

 

Abeness wrote:

The self-adjusting mechanism adjusts the hand brake only. If the
mechanism does not work, the foot brake will not be affected.

Short of picking apart the brake caliper, you could try pushing the
piston all the way back into the caliper (rotating clockwise as you push
it in, just like you would do when replacing brake pads.) Put the
caliper back on and pump the foot brake until it is firm. See if the
hand brake does anything now. With a great deal of luck, this will
jiggle the mechanism just enough that it starts working again.

I have the same problem on an old VW GTi, I am planning on picking up a
complete caliper at the junk yard.