bleeding brakes (by vacuum)

[kenyon wills <imperialist60@xxxxxxxxx>]

That garden sprayer (pressure) idea is ingenious and probably cheaper than
mine.

I used a mity-vac vacuum hand pump.  It's a relatively cheap grey plastic
hand-squeeze tool with a vacuum gauge on it.  It looks like a really
distorted squirt gun from one angle.   I bought 15 feet of clear 1/4"
diameter "surgical" hose at the hardware store.  

I looped the hose over a rafter (you can do it over the car's roof with
something heavy set up there holding it up) and connected the hose to a
bleeder screw at the farthest wheel from the MC and drew a vacuum.  I then
opened the bleeder screw, having topped off the MC to the brim beforehand.
 The vacuum pump is at the other end of the hose, and should be at hand
level if you cut the hose to the appropriate length, but that isn't
crucial.

When the bleeder screw opens, the vacuum sucks fluid from the MC through
the line into the clear hose.  When you are no longer seeing bubbles
coming out and it's just solid fluid being pulled out, you're done.
I did this on a dry, new system and it worked great to pull entirely new
fluid the whole way with me topping off the MC occasionally. 

Repeat with each line from longest (farthest from MC) to shortest and you
should have 100% fluid and 0% air.  The bonus on this one is that if you
pinch off the end of the hose at the bleeder as you remove it, you can
retain the fluid in the clear hose and dump it back into the bottle or
dispose of it if it's not new and clean.   No drippy mess this way.

When the vacuum pressure diminishes and everything settles down, the open
valve can't leak and let air back in, as it has the fluid that came out of
it in the hose still still connected to it, and the bleeder screw is
closed before the hose is removed.  I mormally bleed things once more a
month after changing fluid just to make sure, but usually don't find that
anything changes, hence my faith in the method.

This is the exact opposite mechanical principal from Kerry's pressure
system, but works the same.  I liked being able to see the solid fluid
climb the hose to the doorsill from the wheel just to be certain, but
that's just me.  No bubbles are the main indicator.  


-Kenyon


--- Kerry Pinkerton <pinkertonk@xxxxxxxxx> wrote:
>  Hugh, there is a relatively simply process for pressure bleeding your
> system that will ensure NO air is in the system.  Get a small pump up
> garden
> sprayer. (I think I gave 12 bucks for mine at Home Depot) Find a extra
> master cylinder cap, drill a hole in it and put some type of hose stem
> on it
> that you can adapt to the garden sprayer hose.  Fill the garden hose
> with
> fresh brake fluid and give it a few pumps.  Then start cracking the
> bleeder
> valves.  The fluid will be pushed through the lines under pressure and
> no
> air should remain.
> 
> This is easy with two people but do-able alone.  It doesn't take much
> pressure.
> 
> I did this on my 54 so I could remote fill the master cylinder which was
> under the fragile carpet.  I just put a vacuum cap on the end of the
> modified cap when finished.
> 
> KerryP
> Patch panels fabricated
> Pinkertonk@xxxxxxxxx
> dte.net/57imperial
> Imperials -- 50 Limo, 57 roadster, 61's, 64, 68 Convert, 73, a 66 300
> and a
> bunch of lesser marques
> ----- Original Message -----
> From: Hugh & Therese <hugtrees@xxxxxxxx>
> To: Imperial Mailing List <mailing-list@xxxxxxxxxxxxxxxx>
> Sent: Tuesday, March 18, 2003 12:17 AM
> Subject: IML: bleeding brakes *
> 
> 
> > * Read with a cockney accent for full effect
> >
> > Intending to dive the Imperial on Sunday I backed it out of the garage
> and
> > washed it.  I cannot remember the last time I washed it, so it was
> kind of
> > nice to reacquaint my knuckles with all its nooks, crannies and
> crevices.
> > Things got a little hectic and I ended up not using it and it stayed
> on my
> > short but steep driveway until around 10:00 PM.  Oh, you can only
> imagine
> my
> > joy when I restarted it to move it back into the garage to find I had
> no
> > brakes.  I did when I left the garage, which is level, of course.
> >
> > The friend who helped with the brakes last year, of whom some of you
> do
> not
> > have the highest opinion, and I had discussed the still less than
> acceptable
> > braking I was getting from the car.  I have only tried to bleed and
> adjust
> > the brakes once since last year.  No air was found, but a one or two
> shoes
> > needed to be adjusted, now the new shoes had seated.  We concluded
> there
> was
> > indeed still air in the line and that what we would have to do is jack
> up
> > the rear end for a few days and let the bubbles rise through the fluid
> of
> > their own accord so we could try to expel them once and for all.
> Yesterdays
> > impromptu experiment hopefully indicates that the idea just might
> work.
> So,
> > when rain has moved out of the forecast, and both Mark and I can find
> some
> > time in our crowded schedules, I will park it outside, nose down, and
> see
> if
> > the trapped air cannot be coaxed out of the system.
> >
> > If we should fail I do not know what to do next.  Since two
> professional
> > shops and countless hours of amateur labor have not managed to resolve
> the
> > cars poor brakes, I am left with a rather obvious but unpalatable
> > alternative.
> >
> > Hugh
> >
> >
> >
> >