96 Stratus Brake Problem

Dimished brake performance. New Pad/Rotor, Rear shoes. Lot of pressure
required to stop, getting worse over time. Car has ABS. Brake system bled,
no leaks at calipers or rear wheel cyls.

With engine off, I can press the brake pedal and it will feel firm and stop
several inches from the floor board.

With engine running (in park, not moving), the pedal goes to the floor.

Is it the master cyl, power brake assist, ABS ??

"mkal2" <u25156@uwe> wrote in message news:6494e69a5bf35@uwe...
> Dimished brake performance. New Pad/Rotor, Rear shoes. Lot of pressure
> required to stop, getting worse over time. Car has ABS. Brake system
> bled,
> no leaks at calipers or rear wheel cyls.
>
> With engine off, I can press the brake pedal and it will feel firm and
> stop
> several inches from the floor board.
>
> With engine running (in park, not moving), the pedal goes to the floor.
>
> Is it the master cyl, power brake assist, ABS ??
>

From your description of the problem it sounds like none of the above.
Have you checked the calipers for stuck pistons or sticking calipers slides
? Are the wheel cylinder pistons frozen in their bores ? Are the rear brakes
adjusted properly ? Is the parking brake adjusted properly ? Are you sure
there is no air in the brake system ?

If the master cylinder was bad the pedal should go to the floor whether
the engine is running or not. If the brake booster was bad it should cause a
hard pedal. The ABS should not have any affect on the brake system while
sitting in park.

Thanks for your input on diagnosing the Master Cyl / Booster.

I'm curious as to why the pedal goes to the floor when the engine is running ?
Is the booster creating that much more force than my leg pushing on the pedal
as hard as I can while engine off?

The rears were worn pretty bad, only had about 24K miles on them, original
shoes lasted about 45 K Do you think the rears are more braking than the
fronts?

Since the pads / rotors were replace a few months ago; also worn, and suspect
for pedal travel. The pedal travel did get a bit better with the new
pads/rotors, but still required more brake pressure than normal (normal is
what I compare with my '96 sebring...same brake system). The pistons did move
back freely into the caliper (note, had the bleed screw open when I pushed
them in).

"air in system".....how much fluid should I bleed off? I let the fronts
gravity bleed; replace at least 12 oz. Finished off the bleeding with
somebody assisting; pumping the brake pedal (only 1/2 way down,never to the
floor). Have had success with this process on my chrys and ford cars.

=================================================
=================================================

Mike wrote:
>> Dimished brake performance. New Pad/Rotor, Rear shoes. Lot of pressure
>> required to stop, getting worse over time. Car has ABS. Brake system
>[quoted text clipped - 8 lines]
>>
>> Is it the master cyl, power brake assist, ABS ??
>
> From your description of the problem it sounds like none of the above.
>Have you checked the calipers for stuck pistons or sticking calipers slides
>? Are the wheel cylinder pistons frozen in their bores ? Are the rear brakes
>adjusted properly ? Is the parking brake adjusted properly ? Are you sure
>there is no air in the brake system ?
>
> If the master cylinder was bad the pedal should go to the floor whether
>the engine is running or not. If the brake booster was bad it should cause a
>hard pedal. The ABS should not have any affect on the brake system while
>sitting in park.

If you did not open the bleeders when the job was done then there would be
no reason for air to get into the system. If the rotors were machined and
not to a fine cut you will get that feeling when trying to stop.
You dont state the mileage and keep in mind that if you have alot of
build up around the inside bore of the master cylinder (because the piston
never went that far) and you pushed the brake pedal to the floor (possibly
tearing the seal) now when you press the pedal the fluid is going passed
the seals and causing the fluid to not compress thus making the pedal go
down.
The other thing is when a brake job is done on a vehicle it has a tendency
to feel different then before they were replaced and the owner will acually
think the pedal goes to the floor. If the pedal really went to the floor
the Brake lite would have turned on when this happens and I see no mention
of that happening. Did the brake lite turn on or is it just a matter of
seating the pads to the rotors? Just a thought!!!

Glenn Beasley
Chrysler Tech

No Brake Light ever came on.

I did open the bleeders to do a gravity feed on the front calipers.

rotor fine cut and pedal pressure, pedal travel, are you saying that an
improperly cut rotor, may require excessive pedal pressure, and then I'm
pushing harder on the pedal, causing it to travel further? Shouldn't the
pedal feel firm when the depressed?



damnnickname wrote:
>If you did not open the bleeders when the job was done then there would be
>no reason for air to get into the system. If the rotors were machined and
>not to a fine cut you will get that feeling when trying to stop.
>You dont state the mileage and keep in mind that if you have alot of
>build up around the inside bore of the master cylinder (because the piston
>never went that far) and you pushed the brake pedal to the floor (possibly
>tearing the seal) now when you press the pedal the fluid is going passed
>the seals and causing the fluid to not compress thus making the pedal go
>down.
>The other thing is when a brake job is done on a vehicle it has a tendency
>to feel different then before they were replaced and the owner will acually
>think the pedal goes to the floor. If the pedal really went to the floor
>the Brake lite would have turned on when this happens and I see no mention
>of that happening. Did the brake lite turn on or is it just a matter of
>seating the pads to the rotors? Just a thought!!!
>
>Glenn Beasley
>Chrysler Tech

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"mkal2 via CarKB.com" <u25156@uwe> wrote in message
news:649e36b22890c@uwe...
> No Brake Light ever came on.
>
> I did open the bleeders to do a gravity feed on the front calipers.
>
> rotor fine cut and pedal pressure, pedal travel, are you saying that
an
> improperly cut rotor, may require excessive pedal pressure, and then I'm
> pushing harder on the pedal, causing it to travel further? Shouldn't
the
> pedal feel firm when the depressed?

What I am saying is, if the rotors were not cut fine the pad to rotor
contact will not be sufficient untill the pads seat to them.As far as brake
pedal feel you should know how it is supposed to feel
>
>
>
> damnnickname wrote:
> >If you did not open the bleeders when the job was done then there would
be
> >no reason for air to get into the system. If the rotors were machined and
> >not to a fine cut you will get that feeling when trying to stop.
> >You dont state the mileage and keep in mind that if you have alot of
> >build up around the inside bore of the master cylinder (because the
piston
> >never went that far) and you pushed the brake pedal to the floor
(possibly
> >tearing the seal) now when you press the pedal the fluid is going passed
> >the seals and causing the fluid to not compress thus making the pedal go
> >down.
> >The other thing is when a brake job is done on a vehicle it has a
tendency
> >to feel different then before they were replaced and the owner will
acually
> >think the pedal goes to the floor. If the pedal really went to the floor
> >the Brake lite would have turned on when this happens and I see no
mention
> >of that happening. Did the brake lite turn on or is it just a matter of
> >seating the pads to the rotors? Just a thought!!!
> >
> >Glenn Beasley
> >Chrysler Tech
>
> --
> Message posted via CarKB.com
> http://www.carkb.com/Uwe/Forums.aspx/dodge/200608/1
>