Re: strange brake behavior

On May 5, 12:50=A0pm, "Earle Horton" <earleh_nos...@[EMAIL PROTECTED]
> wrote:
> It's hard to believe, but the Jeep could have been at an angle extreme
> enough for the master cylinder to suck air. =A0That's scary. =A0The part
a=
bout
> the brakes being applied even though you had your foot off the pedal is
> strange though. =A0I would probably replace the master or at least tear
it=

> down for inspection just in case.
>
> Earle
>
> "nrs" <neale...@[EMAIL PROTECTED]
> wrote in message
>
>
news:b4ab20cf-fc1f-407b-b12b-9583f5a054dd@[EMAIL PROTECTED]
>
>
>
> > While wheeling a few days ago, the jeep was at an extreme angle and
> > the engine was about to stall. I was driving off a ledge using the
> > brakes. =A0I realeased the brakes to see if the Jeep would roll
forward
> > a bit and then when I pressed on the brake pedal again it went to the
> > floor with no resistance, I let it out and pressed again and it went
> > down most of the way but I think there was some resistance just before
> > the floor. =A0It seemed like the brakes where being kept applied
despite=

> > my foot being off the pedal. =A0I shut off the engine and restarted
and
> > everything was fine for the rest of the trip and it was also fine the
> > next day around town. =A0There was no fluid loss, the reservoir is
still=

> > full. =A0Any ideas what could have caused this?
>
> > Thanks- Hide quoted text -
>
> - Show quoted text -

What's really strange is that no fluid is missing and the brakes did
not require bleeding.  My best guess so far after looking at the FSM
is that the atmospheric pressure valve could be leaking.  This would
mean that even with the foot off the pedal there is still no vaccuum
at the backside of the diafragm, causing the brakes to stay applied by
the booster itself via the secondary pushrod.  The brake pedal could
come back up moving only the primary pushrod.  What would you
recommend, change the booster or the entire master cylinder and
booster assembly? I'm leaning towards replacing the booster only for
now.