Vacuum brake bleeding

I was trying to bleed my 95 Cherokee brakes, but the fluid hardly
comes out.

I thought of vacuum bleeding, but I wonder how much vacuum do I need.
I don't have a pump, but can I use my household vacuum cleaner as
suction source?

I can take a big jam jar, drill 2 holes on the lid to put in the
tubes, I already have an adaptor to fit the vacuum hose to the tube.

Would there be enough suction to bleed the brakes? Any better ideas
apart from spending a whooping $90 on a bleed kit?


Pete

Peter wrote:

> I was trying to bleed my 95 Cherokee brakes, but the fluid hardly
> comes out.
>
> I thought of vacuum bleeding, but I wonder how much vacuum do I need.
> I don't have a pump, but can I use my household vacuum cleaner as
> suction source?
>
> I can take a big jam jar, drill 2 holes on the lid to put in the
> tubes, I already have an adaptor to fit the vacuum hose to the tube.
>
> Would there be enough suction to bleed the brakes? Any better ideas
> apart from spending a whooping $90 on a bleed kit?
>
>
> Pete

Use a pressure bleeder instead, I have found them to be much more
reliable. You can probably rig one up with a bigass jar, a Schrader
valve (for a wheel) a spare master cylinder cover and some tubing if you
don't want to pay for a ready made one. I have a cheap Motive PRoducts
one and use the crap out of it.

nate

--
replace "fly" with "com" to reply.
http://home.comcast.net/~njnagel

"Peter" > wrote in message
om...
> I was trying to bleed my 95 Cherokee brakes, but the fluid hardly
> comes out.
>
> I thought of vacuum bleeding, but I wonder how much vacuum do I need.
> I don't have a pump, but can I use my household vacuum cleaner as
> suction source?
>

They don't work - I have an A/C vacuum and I've tried different vacuum
levels with various Rube Goldberg contraptions on the bleed screws.

Other than a pressure bleeder, the next best thing is an assistant sitting
in the car pressing the brake petal while you have the bleed screw open.
I usually use my wife for this when I do our vehicles and the procedure
works well except for a rather annoying whining noise. (from the
wife, not the car ;-)

Ted

Make sure the master is bled first before you try to bleed at the
wheels, kinda sounds like this is your problem. If the master is bled
you should have plenty of pressure at the bleeders when the pedal is
pushed. If you are gravity bleeding & have no pressure, thats a
different story. The cheapest pressure bleeder is a 1/16" drill bit & a
blow nozzle for your air hose, vacuum systems as I have seen them used
(pardon the pun) suck. Put the drill bit thru the MC lid & thru the
inside rubber seal at a didderent spot, apply air pressure at a very
slow rate (just enough to slightly bulge the resivoiur) with the
bleeders of choice open & wait for a puddle. Once started they will
usually gravity bleed from there. The new "bleeder hole" in the lid is
too small to matter, for all practical purposes, & can be left there
with no adverse affects. Good luck.

TeGGer® wrote:

> (Peter) floridly penned in
> om:
>
>
>>I was trying to bleed my 95 Cherokee brakes, but the fluid hardly
>>comes out.
>
>
>
> I'm curious what "fluid hardly comes out" means. Are you saying the pedal
> goes to the floor but nothing but air comes out of the bleed nipple?
>
> If you remove the bleed screw do you see goop inside?
>
> Is the bleed screw blocked with rust? Was the rubber cap missing?
>
> Does this happen to ANY bleed screw you try at?
>
> Have you done some work to the brakes, such as master cylinder replacement?
> If so, you may need to bench-bleed the MC first before installing.
>
> If lines have been replaced, there can be a surprising amount of air in the
> system and it may take quite a lot of pumping before you see fluid at the
> caliper or wheel cylinder. You may just not have bled for long enough.
>
> How long did you bleed for and were you using the pedal-push method?
>
>

I've found that on older cars using the pedal-pump method is a good way
to end up replacing the MC. Unless it's been meticulously maintained
the inside of the MC will be rusty outside the normal travel area of the
piston, and wiping the seals over rust will trash them.

nate

--
replace "fly" with "com" to reply.
http://home.comcast.net/~njnagel

In article >,
Nate Nagel > wrote:

> I've found that on older cars using the pedal-pump method is a good way
> to end up replacing the MC. Unless it's been meticulously maintained
> the inside of the MC will be rusty outside the normal travel area of the
> piston, and wiping the seals over rust will trash them.
>
> nate

Put a scrap of 2X4 on the floor under the brake pedal, it will
act as a stop preventing the MC seals from running into the junk
area.

You have got to be kidding right?

Brake fluid absorbs water and becomes useless really quick and you are
telling someone it is cool to have an open hole in the reservoir?

That is a good way to get someone killed!

Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's

pater wrote:
>
> Make sure the master is bled first before you try to bleed at the
> wheels, kinda sounds like this is your problem. If the master is bled
> you should have plenty of pressure at the bleeders when the pedal is
> pushed. If you are gravity bleeding & have no pressure, thats a
> different story. The cheapest pressure bleeder is a 1/16" drill bit & a
> blow nozzle for your air hose, vacuum systems as I have seen them used
> (pardon the pun) suck. Put the drill bit thru the MC lid & thru the
> inside rubber seal at a didderent spot, apply air pressure at a very
> slow rate (just enough to slightly bulge the resivoiur) with the
> bleeders of choice open & wait for a puddle. Once started they will
> usually gravity bleed from there. The new "bleeder hole" in the lid is
> too small to matter, for all practical purposes, & can be left there
> with no adverse affects. Good luck.

"You can probably rig one up with a bigass jar, a Schrader
valve (for a wheel) a spare master cylinder cover and some tubing if
you
don't want to pay for a ready made one"

Does not work for my car, and most likely not for any newer car that
has a cheap plastic brake fluid reservior. Probably work work great on
the 1975 Chevy I once had. When I tried to do that it does not work
because the cap isn't air tight, therefore no pressure. I use a
mightyvac to remove the old fluid from the reservior and then refill
and get another person to pump the brakes. It doesn't take long to do
it that way because you have already gotten out half the fluid before
you start pumping the brakes.

In article >, says...
>
>
>You have got to be kidding right?
>
>Brake fluid absorbs water and becomes useless really quick and you are
>telling someone it is cool to have an open hole in the reservoir?
>
>That is a good way to get someone killed!

All the brake reservoirs I have seen are all vented.
------------
Alex

Alex Rodriguez wrote:
>
> In article >, says...
> >
> >
> >You have got to be kidding right?
> >
> >Brake fluid absorbs water and becomes useless really quick and you are
> >telling someone it is cool to have an open hole in the reservoir?
> >
> >That is a good way to get someone killed!
>
> All the brake reservoirs I have seen are all vented.
> ------------
> Alex

I have never seen a vent going to the fluid compartment! All the fluid
would fast **** out. When you hit the brakes fluid squirts up in the
air a long ways if the cover is off. Same for hitting bumps.

The covers have a vent to allow the inside rubber seal to move down as
fluid goes to the calipers or cylinders due to pad wear, but the inside
seal is air tight for sure!

Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's