Re: brakes

[Peter Golledge <petergg@mincom.com>]

Mike Mulholland
> 
> hi andrew, i tried the bicycle pump approach...it doesn't work because you
> have a limited supply of air and one pump stroke does push fluid in but as
> soon as its done...it all gets pushed back again...over and over. very
> frustrating. you do need a continuous source of air, either as basic as a
> spare tire or a compressor with regulator or an air tank with regulator. you
> only need 15-20lbs pressure. the back brakes are different though because
> they are fed by way of the proportioning valve which doesnt like to open at
> low pressures. i got around this by using the pressure supply and having my
> wife pump the brakes at the same time. after a few strokes the valve stayed
> open by itself. i made my own pressure bleeder...and i have a compressor in
> my shop.

To build my pressure bleeder I used:

a.  The brake res cap off a wreck
b.  Some fuel hose 
c.  A two liter plastic coke bottle (aka pressure tank)
d.  Two valve stems from dead cycle tubes
e.  Cycle pump

To build:

a.  Drill two holes in lid of bottle
b.  Insert valve stems into each hole, glue in place
c.  Remove valve from one valve stem and place one end of
    fuel hose over stem
d.  Drill hole in brake res cap from wreck
e.  Insert fuel hose into brake res cap and glue


To use:

* Attach the cycle pump to the valve stem (the one with the valve in :-)
* Place cap onto brake res (full of nice fresh fluid naturally)
* Pressurise coke bottle using cycle pump
* Bleed away
* Have assistant pump cycle pump from time to time.


Bad ASCII art follows, those with any artistic talent can hit delete
now to avoid nausea.....

                 _________________|-
                 |                  Hose to res cap 
Value stem       | |--------------|-
    ---->  |i|   | |
          -| |---| |--
          |         |
          |         |
          |         |
         /           \
        /             \
       /               \
       |    Coke       |       
       |    Bottle     |       
       |               |       
       |               |       
       |               |       
       |               |       
       |               |       
       -----------------

I now have a compressor and hand pump pressure bleeder, the above
worked for me for a year or so and several brake bleeding sessions.  I
do also recommend a rod cut to length to hold the brake pedal slightly
depressed....

Cheers
-- 
Peter Golledge