1987 Shimano U-Brake how to load spring?

I use my 1987 Diamondback Arrival for a commuter. The Shimano U-brake,
mounted to the chainstays, gets pretty nasty towards the end of winter
(year after year) and today one of the brake arms decided to freeze up
on its pivot post. So I disassembled it, and got it all working again
- almost. Unfortunately, I cannot figure out how to reassemble the
spring, metal keeper (with guide hole) and plastic cap into the brake
arm. If the spring has any tension, the metal cap rides on the cast
buttress on the brake arm so there is not room to get the plastic cap
on. The trick on how to do this eludes me - anybody remember how to
reassemble these?

TIA

Steve

On 13 Mar 2006 22:52:26 -0800, "Steve" wrote:

I use my 1987 Diamondback Arrival for a commuter. The Shimano U-brake,
mounted to the chainstays, gets pretty nasty towards the end of winter
(year after year) and today one of the brake arms decided to freeze up
on its pivot post. So I disassembled it, and got it all working again
- almost. Unfortunately, I cannot figure out how to reassemble the
spring, metal keeper (with guide hole) and plastic cap into the brake
arm. If the spring has any tension, the metal cap rides on the cast
buttress on the brake arm so there is not room to get the plastic cap
on. The trick on how to do this eludes me - anybody remember how to
reassemble these?

TIA

Steve

Barnett's Manual has exploded drawings of Shimano and Dia-Compe
U-brakes. There was a time you could find this manual on line.

Direct ranscription from the pdf version of Barnett's Manual -
Chapter 36, page 40:

Assembling Shimano-type U-brake
1. Grease springs

2. Install gold spring in arm without pinch bolt. Long end should be
pointing out and should be winding in clockwise direction.

3. Install silver spring in the arm with pinch bolt. Long end should
be pointing out and should be winding in counterclockwise direction.

4. Install tension plates with Allen fitting face out, with end of
spring in hole in plate.

5. Plate on gold spring should be wound clockwise about 60 degrees,
until tab on perimeter of plate is past stop inside arm. Then, press
in firmly on tension plate with Allen wrench seat it in arm.

6. Plate on silver spring should be wound counterclockwise about 60
degrees, until tab on perimeter of plate is past stop inside arm.
Then, press in firmly on tension plate with Allen wrench seat it in
arm.

7. Place dustcap(s) over tension plate so protruding spring will
engage slot in back of dust cap, and so two notches in back perimeter
of dust cap line up with stop tabs inside arm(s).
------
There's also the library which should have a selection of, now rather
dated, bicycle repair books with a drawing.

HTH

My first encounter with U-brakes was a partially and incorrectly
re-assembled one missing a bushing. Not fun until I got a book and
the missing bushing.
--
zk