Question about Brakes / Master Cylinder
 

96 Chevrolet C1500 PU 2 wheel drive power brakes, front disc, rear
drum.

Hi All!

My truck evidently had a caliper get stuck and it quickly wore down the
inner brake pad on one wheel. The master cylinder fluid was down to the
bottom of the reservoir, so I wondered if I might have gotten some air
into it. Anyway, I have replaced the front calipers and pads, and used
the gravity method to bleed all four wheels. I inspected the back shoes
and wheel cylinders and they are OK. Now I have good brakes again, but
the pedal travels half the distance to the floor before the brakes
begin to kick in. I think it should have about an inch of travel :-).

So, my question is, if air DID get into the master cylinder, would it
have travelled to the wheels and now be eliminated by the wheel
bleeding, or should I actually bleed it now as part of my brake job? I
checked the master cylinder and it is dry (not externally leaking), it
doesn't bleed down under pressure, and the system is not losing fluid,
so I think the MC is OK.

Thanks,
Libby

Shouldnt the master cylinder be full? maybe thats your problem. or am I
misunderstanding?

duh. I get it. Dry as in the outside of the MC.
Sounds like a rebleed is needed to me and that you correct that air got in.

On 14 Dec 2004 06:02:57 -0800, wrote:

>So, my question is, if air DID get into the master cylinder, would it
>have travelled to the wheels and now be eliminated by the wheel
>bleeding, or should I actually bleed it now as part of my brake job? I
>checked the master cylinder and it is dry (not externally leaking), it
>doesn't bleed down under pressure, and the system is not losing fluid,
>so I think the MC is OK.


Gravity bleed often times isn't good enough to get the bubbles out.
Bleed the brakes the regular way and make sure the back ones are
adjusted correctly.

If you dont have a helper you can get a one man bleeding kit for
around $5 at the parts store.

Steve B.

I don't have a helper so tell me more about this one man bleeding kit.
All I could find was a plastic Mity-Vac for $30.00. They also had a kit
that included a hose and a bottle to catch the fluid, but you would
still need a pedal pumper or some way to push / suck the air bubbles
out. I looked at O'Reilly's and Auto Zone.

Steve B. wrote:
> On 14 Dec 2004 06:02:57 -0800, wrote:
>
> >So, my question is, if air DID get into the master cylinder, would
it
> >have travelled to the wheels and now be eliminated by the wheel
> >bleeding, or should I actually bleed it now as part of my brake job?
I
> >checked the master cylinder and it is dry (not externally leaking),
it
> >doesn't bleed down under pressure, and the system is not losing
fluid,
> >so I think the MC is OK.
>
>
> Gravity bleed often times isn't good enough to get the bubbles out.
> Bleed the brakes the regular way and make sure the back ones are
> adjusted correctly.
>
> If you dont have a helper you can get a one man bleeding kit for
> around $5 at the parts store.
>
> Steve B.

"Libby Chantel" wrote

> I don't have a helper so tell me more about this one man bleeding kit.
> All I could find was a plastic Mity-Vac for $30.00. They also had a kit
> that included a hose and a bottle to catch the fluid, but you would
> still need a pedal pumper or some way to push / suck the air bubbles
> out. I looked at O'Reilly's and Auto Zone.

The second one sounds like it. Just a hose that clamps onto the brake
bleeder screw, the other end in the jar. A check valve at the jar end keeps
air from going back up the hose. Attach the hose, open the bleeder screw
a bit, and start pumping. After a few strokes, or 5, or 6... tighten the bleeder,
pop off the hose, and you're done (or move to the next wheel).

Don't forget to check and top-up the master cylinder while you're doing this,
otherwise you'll suck in more air, and have to start all over again.

Do I need to bleed the MC first or will any air that is in it get
pushed out to the wheels? It is full of fluid.

On 16 Dec 2004 06:04:18 -0800, "Libby Chantel"
> wrote:

>Do I need to bleed the MC first or will any air that is in it get
>pushed out to the wheels? It is full of fluid.

Some ABS vehicles have special bleeding procedures if you get air in
the master cylinder. I don't know if yours does or not. If I were
doing this I would probably do a thourough bleed of the four corners
and see what you get.

Steve B.