[Author Index] [Date Index] [Thread Index]
[Date Prev][Date Next][Thread Prev][Thread Next]

Mushy rear brake - get a bigger hammer



	No joke, sometimes it works.
	Up until two years ago I raced cross country dirt bikes since '76 and
went through a lot of brake pads. In addition I bleed and replaced the
brake fluid completely almost every race because of contamination and
just plain worn out fluid in racing applications. You can tell the
difference. There are a couple of observations that I'll share if you
want. If not then just ignore my ramblings. I'm no expert, but here's
what we all did a lot.
	 
	Take about a foot and a half of clear tubing that fits the bleeder
nipples tightly. Form this tubing into a length of about three inches
and then make two loops of the tubing about three or four inches in
diameter. Zip tie or tape it together loosely with the remaining tubing
hanging loose to drain into the catch receptacle. Place the short end of
the tubing on the nipple after running it through the closed end of a
box end wrench to fit the nipple. Install the brake bleeding line with
the two loops of tubing in the upward position. You might need or want
to temporarily tie the loops up with a string or very loose bungie to
keep it from rotating. Start the normal bleeding procedure by
pressurizing the brake line, opening the nipple until half way pedal
fall, tighten the nipple, repeat about three times. At this point you
should have a fluid build up about half way around the two loops of
tubing. If not repeat the regular bleeding process until you have at
least one of the loops half full of fluid. Now you can open the bleeder
nipple a good amount and pump away. Watch the master cylinder and keep
it full as not to pull air into the line again. The loops of tubing will
keep the fluid in their lower area and keep air from reentering the
system during the pumps. This really speeds the process up. In addition,
you can now see the brake fluid and any bubbles working themselves out
of the system. When you do a complete fluid change, that I recommend at
least yearly, you can also see the color change as the new fluid works
it's way through the brake system and into your trick bleeding line! I
usually took a rubber hammer and tapped the caliper lightly a few times
as I was bleeding the brakes to jar any stuck air bubbles loose.
	
	The other method also worked and requires a plastic syringe injector.
Instead of pulling a vacuum you forced the brake fluid into the system
with the injector through the brake caliper nipple, through the brake
line, into the master cylinder. Bubbles like to go to the surface and
since the master cylinder is higher on the bike you are going the way
the bubble wants to travel anyway. Not trying to force a bubble down
deeper into the system. Did you ever think why we want to force a bubble
that wants to float down instead of up? Sometimes a tap was still
required. Bubbles like to stick to cavities in the calipers.
	
	Try experimenting with the loop diameter, etc. but it works. Cheaper at
about $1.00. If not, go to Auto Zone and but the pump.
- -- 
"The truth is out there"

Jack "Rude Dog" Hays, Red Triumph ST "Merlin"
Raytheon TI Systems Company
Harpoon Manufacturing 
Voice Number: 972-952-5065
Pager Number: 972-598-0346
I'll see you on the dark side of the moon.

 *   *   *   *   *   *   *   *   *   *   *   *   *   *   *   *   *   *   *
 The ST Mailing list is sponsored by the Unofficial ST Website
   http://www.TriumphNet.com/st for ST and Mailing List info

=-=-=-= Next Message =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=