"Jamie Calder" <jcalder3@cfl.rr.com> wrote:
: What's the easiest 1 man brake bleeding method (without using expensive
: equipment)?
I hate bleeding brakes. I'm never really quite *sure* if I
got all the air out. :-P
I have used two methods - the Mighty-Vac and the "tube in a
jar":
The Mighty-Vac method has you putting the tube on the
bleeder and building up a vaccum with the pump, then just
open up the bleeder and suck the fluid (and air) out, while
maintaining the vacuum by pumping it up as necessary. The
advantage to this method is that you are right there by the
bleeder and you can watch it at all times. A disadvantage
is that it seems to suck in air from around the bleeder,
which makes it look like air is coming out of the brake
lines, when in fact its just outside air coming between
the bleeder and the hose or through the threads of the
bleeder and then out the end of the bleeder. Its pretty
annoying. Also, I'm not sure if this method would purge
air that is further away from the bleeder - would it
suck an air pocket that was near the master cylinder out?
I'm not sure. Also, I think some master cylinders may
have a check valve to prevent all of the brake fluid
leaking out in the event of a leak, in which case this
method might not work? Anybody know for sure?
The "tube in a jar" method basically works by putting a
little brake fluid in a jar and running a tube between
the bleeder and the jar. You open the bleeder and then
go step on the brake pedal, and run back to close the
bleeder. The end of the tube is submerged in brake fluid
so that when you release the brake pedal and it starts drawing
the fluid back in, it will bring up brake fluid instead of
sucking air back into the system. If possible, I like to
hang the jar above the bleeder so that if there is an air
bubble that comes out the bleeder but which is still in the
tube when you release the brake pedal, it won't go back
up into the bleeder. An air bubble will rise, so if the jar
is higher than the bleeder, those air bubbles will go up
towards the jar and away from the bleeder. This method
is certainly the cheaper of the two as you don't need the
$20-30 vacuum pump, but the main disadvantage is that
you can't watch what is going on. Did any air bubbles come
out? Did they go back into the bleeder when you released
the pedal? Who knows? Unless you feel like setting up a
video camera or something, this is just something you have
to hope you got right. And of course, having to run back
from the driver's seat to the brake you are working on is
annoying.
You will want to bleed your brakes from the furthest point
away from the master cylinder to the closest point. (I'm
not sure why, but that is what "they" say to do.) This will
vary depending on how your brake lines are run, but usually it
is the right rear, left rear, right front, then left front. If
you have ABS, you might also have an ABS module or two which needs
to be bled. All the while, you will also have to make sure to
keep your master cylinder full otherwise you can suck air
into the system there and have to start all over. I have always
left the caps on the master cylinder when bleeding the brakes using
the "tube in a jar" method becasue if you leave them off and press
the brake pedal, a geyser of brake fluid will spray up out of there.
I'm also never quite sure how long I should keep bleeding
the brakes. How many pedal pumps is necessary to ensure that any
air near the master cylinder has made it out the bleeder? If
there is some air near the master cylinder and I'm working on the
right rear, and I manage to get it to the back and in the tube
between the rear T and the right rear bleeder, then quit under
the assumption that no more air is going to come out, its just
gonna stay there as I bleed the rest of them, in which case what
was the point of bleeding in the first place? :-) Seems like
what we need is something that would inject brake fluid underneath
the master cylinder, with returns from each bleeder valve going
back to a reservoir where it gets injected back under the master
cylinder. This way, no fluid is lost, you can just run the pump
for a few minutes and then close off the bleeders one by one.
Oh well.
Anyhoo, that's how I do it, for what its worth. I hope
it helps! Did I mention that I hate bleeding brakes? :-)
Hey, if anybody has any easier ways to do it, I am all ears! :-)
--
-Jon-
.- Jon Steiger -- jon@dakota-truck.net or jon@jonsteiger.com -.
| '96 Kolb Firefly, '96 Suzuki Intruder, Miscellaneous Mopars |
`-------------------------------- http://www.jonsteiger.com --'
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