Hi, brake level fluid never drops in reservoir, no leaks at any calliper
(pistons), today drove the car for 2 hours brake pedal firm, not spongy, car
brakes very well, after 2 hours, brake pedal goes to the floor little
pressure, pumped the brake pedal 2 twice got a firm brake pedal, then brake
pedal went to the floor again, pumped brake pedal twice got a firm brake
pedal again, brake pedal after driving another hour is firm and have good
brakes no sign of pressure dropping!!
Still looking for advice guys, I changed the master cylinder with a new one
when this symptom first happened, I guess the original problem was not the
master cylinder after all, I would have thought that problem is not a master
cylinder, since the problem still occurs.
checked so far..
No fluid leaks on ground.
Brake reservoir level does not drop.
car brakes in a straight line, tried this many times, perfect braking,
Handbrake (discs) holds car perfectly, and releases with no dragging, don't
think there is a seized piston (calliper)
What else is there to check,
brake pressure valve?
Servo? when the brake pedal pressure fell I stopped, switched off the engine
and pressed the pedal a couple of times and the pedal still went to the
floor
ABS???

Nad




<John> wrote in message news:vhp821lavdlr8k5dabvok0conp76vtsmg6@4ax.com...
> What is your brake fluid level doing, are you loosing any, check at
> the wheel (slave) cylinders as well.
> Best of luck, John
> 1990 V8 Quattro
> On Sun, 27 Feb 2005 17:46:52 GMT, "Nadia" <frogmore89@hotmail.com>
> wrote:
>
>>Can anyone suggest a cure for my UK Audi 80, I am at my wits end.
>>When pressing the brake pedal, the pedal was occasionally going nearly to
>>the floor, when pumped twice it would be OK and the brake pedal pressure
>>would be fine for days, I replaced the master cylinder with a new one from
>>Europarts UK and everything has been OK for a week, now the original
>>problem
>>has happened again, brake pedal will go to the floor and pumped twice it
>>will have a good brake pedal and the brake pedal pressure
>>would be OK, brake pedal pressure is good and when braking car does not
>>veer
>>from a straight line,
>> can anyone diagnose this problem as to why
>>brake pedal pressure keeps dropping from time to time? can't see any
>>leaks,
>>master cyl reservoir fluid level is not dropping
>>Ps my audi 80 1.9TDI avant has got ABS discs brakes all round, 1994
>>model.
>>Thanks
>>
>>
>

 

Hi, brake level fluid never drops in reservoir, no leaks at any calliper
(pistons), today drove the car for 2 hours brake pedal firm, not spongy, car
brakes very well, after 2 hours, brake pedal goes to the floor little
pressure, pumped the brake pedal 2 twice got a firm brake pedal, then brake
pedal went to the floor again, pumped brake pedal twice got a firm brake
pedal again, brake pedal after driving another hour is firm and have good
brakes no sign of pressure dropping!!
Still looking for advice guys, I changed the master cylinder with a new one
when this symptom first happened, I guess the original problem was not the
master cylinder after all, I would have thought that problem is not a master
cylinder, since the problem still occurs.
checked so far..
No fluid leaks on ground.
Brake reservoir level does not drop.
car brakes in a straight line, tried this many times, perfect braking,
Handbrake (discs) holds car perfectly, and releases with no dragging, don't
think there is a seized piston (calliper)
What else is there to check,
brake pressure valve?
Servo? when the brake pedal pressure fell I stopped, switched off the engine
and pressed the pedal a couple of times and the pedal still went to the
floor
ABS???

Nad




<John> wrote in message news:vhp821lavdlr8k5dabvok0conp76vtsmg6@4ax.com...
> What is your brake fluid level doing, are you loosing any, check at
> the wheel (slave) cylinders as well.
> Best of luck, John
> 1990 V8 Quattro
> On Sun, 27 Feb 2005 17:46:52 GMT, "Nadia" <frogmore89@hotmail.com>
> wrote:
>
>>Can anyone suggest a cure for my UK Audi 80, I am at my wits end.
>>When pressing the brake pedal, the pedal was occasionally going nearly to
>>the floor, when pumped twice it would be OK and the brake pedal pressure
>>would be fine for days, I replaced the master cylinder with a new one from
>>Europarts UK and everything has been OK for a week, now the original
>>problem
>>has happened again, brake pedal will go to the floor and pumped twice it
>>will have a good brake pedal and the brake pedal pressure
>>would be OK, brake pedal pressure is good and when braking car does not
>>veer
>>from a straight line,
>> can anyone diagnose this problem as to why
>>brake pedal pressure keeps dropping from time to time? can't see any
>>leaks,
>>master cyl reservoir fluid level is not dropping
>>Ps my audi 80 1.9TDI avant has got ABS discs brakes all round, 1994
>>model.
>>Thanks
>>
>>
>

 

Suspect air in the system then.
Have you bled the system carefully, at master cylinder then each caliper in
turn? The order is Master Cyl / RH Rear / LH Rear / RH Front / LH Front.
When you are bleeding the rear cylinders you need to press the brake
regulator lever also. (you'll need an assistant!)

"Nadia" <frogmore89@hotmail.com> wrote in message
news:Oe6Vd.26548$8B3.26282@text.news.blueyonder.co .uk...
> Hi, brake level fluid never drops in reservoir, no leaks at any calliper
> (pistons), today drove the car for 2 hours brake pedal firm, not spongy,
> car brakes very well, after 2 hours, brake pedal goes to the floor little
> pressure, pumped the brake pedal 2 twice got a firm brake pedal, then
> brake pedal went to the floor again, pumped brake pedal twice got a firm
> brake pedal again, brake pedal after driving another hour is firm and have
> good brakes no sign of pressure dropping!!
> Still looking for advice guys, I changed the master cylinder with a new
> one when this symptom first happened, I guess the original problem was not
> the master cylinder after all, I would have thought that problem is not a
> master cylinder, since the problem still occurs.
> checked so far..
> No fluid leaks on ground.
> Brake reservoir level does not drop.
> car brakes in a straight line, tried this many times, perfect braking,
> Handbrake (discs) holds car perfectly, and releases with no dragging,
> don't think there is a seized piston (calliper)
> What else is there to check,
> brake pressure valve?
> Servo? when the brake pedal pressure fell I stopped, switched off the
> engine and pressed the pedal a couple of times and the pedal still went to
> the floor
> ABS???
>
> Nad
>
>
>
>
> <John> wrote in message news:vhp821lavdlr8k5dabvok0conp76vtsmg6@4ax.com...
>> What is your brake fluid level doing, are you loosing any, check at
>> the wheel (slave) cylinders as well.
>> Best of luck, John
>> 1990 V8 Quattro
>> On Sun, 27 Feb 2005 17:46:52 GMT, "Nadia" <frogmore89@hotmail.com>
>> wrote:
>>
>>>Can anyone suggest a cure for my UK Audi 80, I am at my wits end.
>>>When pressing the brake pedal, the pedal was occasionally going nearly to
>>>the floor, when pumped twice it would be OK and the brake pedal pressure
>>>would be fine for days, I replaced the master cylinder with a new one
>>>from
>>>Europarts UK and everything has been OK for a week, now the original
>>>problem
>>>has happened again, brake pedal will go to the floor and pumped twice it
>>>will have a good brake pedal and the brake pedal pressure
>>>would be OK, brake pedal pressure is good and when braking car does not
>>>veer
>>>from a straight line,
>>> can anyone diagnose this problem as to why
>>>brake pedal pressure keeps dropping from time to time? can't see any
>>>leaks,
>>>master cyl reservoir fluid level is not dropping
>>>Ps my audi 80 1.9TDI avant has got ABS discs brakes all round, 1994
>>>model.
>>>Thanks
>>>
>>>
>>
>
>

 

Suspect air in the system then.
Have you bled the system carefully, at master cylinder then each caliper in
turn? The order is Master Cyl / RH Rear / LH Rear / RH Front / LH Front.
When you are bleeding the rear cylinders you need to press the brake
regulator lever also. (you'll need an assistant!)

"Nadia" <frogmore89@hotmail.com> wrote in message
news:Oe6Vd.26548$8B3.26282@text.news.blueyonder.co .uk...
> Hi, brake level fluid never drops in reservoir, no leaks at any calliper
> (pistons), today drove the car for 2 hours brake pedal firm, not spongy,
> car brakes very well, after 2 hours, brake pedal goes to the floor little
> pressure, pumped the brake pedal 2 twice got a firm brake pedal, then
> brake pedal went to the floor again, pumped brake pedal twice got a firm
> brake pedal again, brake pedal after driving another hour is firm and have
> good brakes no sign of pressure dropping!!
> Still looking for advice guys, I changed the master cylinder with a new
> one when this symptom first happened, I guess the original problem was not
> the master cylinder after all, I would have thought that problem is not a
> master cylinder, since the problem still occurs.
> checked so far..
> No fluid leaks on ground.
> Brake reservoir level does not drop.
> car brakes in a straight line, tried this many times, perfect braking,
> Handbrake (discs) holds car perfectly, and releases with no dragging,
> don't think there is a seized piston (calliper)
> What else is there to check,
> brake pressure valve?
> Servo? when the brake pedal pressure fell I stopped, switched off the
> engine and pressed the pedal a couple of times and the pedal still went to
> the floor
> ABS???
>
> Nad
>
>
>
>
> <John> wrote in message news:vhp821lavdlr8k5dabvok0conp76vtsmg6@4ax.com...
>> What is your brake fluid level doing, are you loosing any, check at
>> the wheel (slave) cylinders as well.
>> Best of luck, John
>> 1990 V8 Quattro
>> On Sun, 27 Feb 2005 17:46:52 GMT, "Nadia" <frogmore89@hotmail.com>
>> wrote:
>>
>>>Can anyone suggest a cure for my UK Audi 80, I am at my wits end.
>>>When pressing the brake pedal, the pedal was occasionally going nearly to
>>>the floor, when pumped twice it would be OK and the brake pedal pressure
>>>would be fine for days, I replaced the master cylinder with a new one
>>>from
>>>Europarts UK and everything has been OK for a week, now the original
>>>problem
>>>has happened again, brake pedal will go to the floor and pumped twice it
>>>will have a good brake pedal and the brake pedal pressure
>>>would be OK, brake pedal pressure is good and when braking car does not
>>>veer
>>>from a straight line,
>>> can anyone diagnose this problem as to why
>>>brake pedal pressure keeps dropping from time to time? can't see any
>>>leaks,
>>>master cyl reservoir fluid level is not dropping
>>>Ps my audi 80 1.9TDI avant has got ABS discs brakes all round, 1994
>>>model.
>>>Thanks
>>>
>>>
>>
>
>

 

Suspect air in the system then.
Have you bled the system carefully, at master cylinder then each caliper in
turn? The order is Master Cyl / RH Rear / LH Rear / RH Front / LH Front.
When you are bleeding the rear cylinders you need to press the brake
regulator lever also. (you'll need an assistant!)

"Nadia" <frogmore89@hotmail.com> wrote in message
news:Oe6Vd.26548$8B3.26282@text.news.blueyonder.co .uk...
> Hi, brake level fluid never drops in reservoir, no leaks at any calliper
> (pistons), today drove the car for 2 hours brake pedal firm, not spongy,
> car brakes very well, after 2 hours, brake pedal goes to the floor little
> pressure, pumped the brake pedal 2 twice got a firm brake pedal, then
> brake pedal went to the floor again, pumped brake pedal twice got a firm
> brake pedal again, brake pedal after driving another hour is firm and have
> good brakes no sign of pressure dropping!!
> Still looking for advice guys, I changed the master cylinder with a new
> one when this symptom first happened, I guess the original problem was not
> the master cylinder after all, I would have thought that problem is not a
> master cylinder, since the problem still occurs.
> checked so far..
> No fluid leaks on ground.
> Brake reservoir level does not drop.
> car brakes in a straight line, tried this many times, perfect braking,
> Handbrake (discs) holds car perfectly, and releases with no dragging,
> don't think there is a seized piston (calliper)
> What else is there to check,
> brake pressure valve?
> Servo? when the brake pedal pressure fell I stopped, switched off the
> engine and pressed the pedal a couple of times and the pedal still went to
> the floor
> ABS???
>
> Nad
>
>
>
>
> <John> wrote in message news:vhp821lavdlr8k5dabvok0conp76vtsmg6@4ax.com...
>> What is your brake fluid level doing, are you loosing any, check at
>> the wheel (slave) cylinders as well.
>> Best of luck, John
>> 1990 V8 Quattro
>> On Sun, 27 Feb 2005 17:46:52 GMT, "Nadia" <frogmore89@hotmail.com>
>> wrote:
>>
>>>Can anyone suggest a cure for my UK Audi 80, I am at my wits end.
>>>When pressing the brake pedal, the pedal was occasionally going nearly to
>>>the floor, when pumped twice it would be OK and the brake pedal pressure
>>>would be fine for days, I replaced the master cylinder with a new one
>>>from
>>>Europarts UK and everything has been OK for a week, now the original
>>>problem
>>>has happened again, brake pedal will go to the floor and pumped twice it
>>>will have a good brake pedal and the brake pedal pressure
>>>would be OK, brake pedal pressure is good and when braking car does not
>>>veer
>>>from a straight line,
>>> can anyone diagnose this problem as to why
>>>brake pedal pressure keeps dropping from time to time? can't see any
>>>leaks,
>>>master cyl reservoir fluid level is not dropping
>>>Ps my audi 80 1.9TDI avant has got ABS discs brakes all round, 1994
>>>model.
>>>Thanks
>>>
>>>
>>
>
>

 

Could also be water in the (old?) brake fluid.
If cold no problem, after heating up it becomes steam which can be
pressed together ---> strange breaking behaviour.
(I hope you understand what I mean, english is not my native tongue)

"Fred" <f@manzzz.com> wrote in news:38kaj7F5okqqaU1@individual.net:

> Suspect air in the system then.
> Have you bled the system carefully, at master cylinder then each
> caliper in turn? The order is Master Cyl / RH Rear / LH Rear / RH
> Front / LH Front. When you are bleeding the rear cylinders you need to
> press the brake regulator lever also. (you'll need an assistant!)
>
> "Nadia" <frogmore89@hotmail.com> wrote in message
> news:Oe6Vd.26548$8B3.26282@text.news.blueyonder.co .uk...
>> Hi, brake level fluid never drops in reservoir, no leaks at any
>> calliper (pistons), today drove the car for 2 hours brake pedal firm,
>> not spongy, car brakes very well, after 2 hours, brake pedal goes to
>> the floor little pressure, pumped the brake pedal 2 twice got a firm
>> brake pedal, then brake pedal went to the floor again, pumped brake
>> pedal twice got a firm brake pedal again, brake pedal after driving
>> another hour is firm and have good brakes no sign of pressure
>> dropping!! Still looking for advice guys, I changed the master
>> cylinder with a new one when this symptom first happened, I guess the
>> original problem was not the master cylinder after all, I would have
>> thought that problem is not a master cylinder, since the problem
>> still occurs. checked so far..
>> No fluid leaks on ground.
>> Brake reservoir level does not drop.
>> car brakes in a straight line, tried this many times, perfect
>> braking, Handbrake (discs) holds car perfectly, and releases with no
>> dragging, don't think there is a seized piston (calliper)
>> What else is there to check,
>> brake pressure valve?
>> Servo? when the brake pedal pressure fell I stopped, switched off the
>> engine and pressed the pedal a couple of times and the pedal still
>> went to the floor
>> ABS???
>>
>> Nad
>>
>>
>>
>>
>> <John> wrote in message
>> news:vhp821lavdlr8k5dabvok0conp76vtsmg6@4ax.com...
>>> What is your brake fluid level doing, are you loosing any, check at
>>> the wheel (slave) cylinders as well.
>>> Best of luck, John
>>> 1990 V8 Quattro
>>> On Sun, 27 Feb 2005 17:46:52 GMT, "Nadia" <frogmore89@hotmail.com>
>>> wrote:
>>>
>>>>Can anyone suggest a cure for my UK Audi 80, I am at my wits end.
>>>>When pressing the brake pedal, the pedal was occasionally going
>>>>nearly to the floor, when pumped twice it would be OK and the brake
>>>>pedal pressure would be fine for days, I replaced the master
>>>>cylinder with a new one from
>>>>Europarts UK and everything has been OK for a week, now the original
>>>>problem
>>>>has happened again, brake pedal will go to the floor and pumped
>>>>twice it will have a good brake pedal and the brake pedal pressure
>>>>would be OK, brake pedal pressure is good and when braking car does
>>>>not veer
>>>>from a straight line,
>>>> can anyone diagnose this problem as to why
>>>>brake pedal pressure keeps dropping from time to time? can't see any
>>>>leaks,
>>>>master cyl reservoir fluid level is not dropping
>>>>Ps my audi 80 1.9TDI avant has got ABS discs brakes all round, 1994
>>>>model.
>>>>Thanks
>>>>
>>>>
>>>
>>
>>
>
>

 

Could also be water in the (old?) brake fluid.
If cold no problem, after heating up it becomes steam which can be
pressed together ---> strange breaking behaviour.
(I hope you understand what I mean, english is not my native tongue)

"Fred" <f@manzzz.com> wrote in news:38kaj7F5okqqaU1@individual.net:

> Suspect air in the system then.
> Have you bled the system carefully, at master cylinder then each
> caliper in turn? The order is Master Cyl / RH Rear / LH Rear / RH
> Front / LH Front. When you are bleeding the rear cylinders you need to
> press the brake regulator lever also. (you'll need an assistant!)
>
> "Nadia" <frogmore89@hotmail.com> wrote in message
> news:Oe6Vd.26548$8B3.26282@text.news.blueyonder.co .uk...
>> Hi, brake level fluid never drops in reservoir, no leaks at any
>> calliper (pistons), today drove the car for 2 hours brake pedal firm,
>> not spongy, car brakes very well, after 2 hours, brake pedal goes to
>> the floor little pressure, pumped the brake pedal 2 twice got a firm
>> brake pedal, then brake pedal went to the floor again, pumped brake
>> pedal twice got a firm brake pedal again, brake pedal after driving
>> another hour is firm and have good brakes no sign of pressure
>> dropping!! Still looking for advice guys, I changed the master
>> cylinder with a new one when this symptom first happened, I guess the
>> original problem was not the master cylinder after all, I would have
>> thought that problem is not a master cylinder, since the problem
>> still occurs. checked so far..
>> No fluid leaks on ground.
>> Brake reservoir level does not drop.
>> car brakes in a straight line, tried this many times, perfect
>> braking, Handbrake (discs) holds car perfectly, and releases with no
>> dragging, don't think there is a seized piston (calliper)
>> What else is there to check,
>> brake pressure valve?
>> Servo? when the brake pedal pressure fell I stopped, switched off the
>> engine and pressed the pedal a couple of times and the pedal still
>> went to the floor
>> ABS???
>>
>> Nad
>>
>>
>>
>>
>> <John> wrote in message
>> news:vhp821lavdlr8k5dabvok0conp76vtsmg6@4ax.com...
>>> What is your brake fluid level doing, are you loosing any, check at
>>> the wheel (slave) cylinders as well.
>>> Best of luck, John
>>> 1990 V8 Quattro
>>> On Sun, 27 Feb 2005 17:46:52 GMT, "Nadia" <frogmore89@hotmail.com>
>>> wrote:
>>>
>>>>Can anyone suggest a cure for my UK Audi 80, I am at my wits end.
>>>>When pressing the brake pedal, the pedal was occasionally going
>>>>nearly to the floor, when pumped twice it would be OK and the brake
>>>>pedal pressure would be fine for days, I replaced the master
>>>>cylinder with a new one from
>>>>Europarts UK and everything has been OK for a week, now the original
>>>>problem
>>>>has happened again, brake pedal will go to the floor and pumped
>>>>twice it will have a good brake pedal and the brake pedal pressure
>>>>would be OK, brake pedal pressure is good and when braking car does
>>>>not veer
>>>>from a straight line,
>>>> can anyone diagnose this problem as to why
>>>>brake pedal pressure keeps dropping from time to time? can't see any
>>>>leaks,
>>>>master cyl reservoir fluid level is not dropping
>>>>Ps my audi 80 1.9TDI avant has got ABS discs brakes all round, 1994
>>>>model.
>>>>Thanks
>>>>
>>>>
>>>
>>
>>
>
>

 

Could also be water in the (old?) brake fluid.
If cold no problem, after heating up it becomes steam which can be
pressed together ---> strange breaking behaviour.
(I hope you understand what I mean, english is not my native tongue)

"Fred" <f@manzzz.com> wrote in news:38kaj7F5okqqaU1@individual.net:

> Suspect air in the system then.
> Have you bled the system carefully, at master cylinder then each
> caliper in turn? The order is Master Cyl / RH Rear / LH Rear / RH
> Front / LH Front. When you are bleeding the rear cylinders you need to
> press the brake regulator lever also. (you'll need an assistant!)
>
> "Nadia" <frogmore89@hotmail.com> wrote in message
> news:Oe6Vd.26548$8B3.26282@text.news.blueyonder.co .uk...
>> Hi, brake level fluid never drops in reservoir, no leaks at any
>> calliper (pistons), today drove the car for 2 hours brake pedal firm,
>> not spongy, car brakes very well, after 2 hours, brake pedal goes to
>> the floor little pressure, pumped the brake pedal 2 twice got a firm
>> brake pedal, then brake pedal went to the floor again, pumped brake
>> pedal twice got a firm brake pedal again, brake pedal after driving
>> another hour is firm and have good brakes no sign of pressure
>> dropping!! Still looking for advice guys, I changed the master
>> cylinder with a new one when this symptom first happened, I guess the
>> original problem was not the master cylinder after all, I would have
>> thought that problem is not a master cylinder, since the problem
>> still occurs. checked so far..
>> No fluid leaks on ground.
>> Brake reservoir level does not drop.
>> car brakes in a straight line, tried this many times, perfect
>> braking, Handbrake (discs) holds car perfectly, and releases with no
>> dragging, don't think there is a seized piston (calliper)
>> What else is there to check,
>> brake pressure valve?
>> Servo? when the brake pedal pressure fell I stopped, switched off the
>> engine and pressed the pedal a couple of times and the pedal still
>> went to the floor
>> ABS???
>>
>> Nad
>>
>>
>>
>>
>> <John> wrote in message
>> news:vhp821lavdlr8k5dabvok0conp76vtsmg6@4ax.com...
>>> What is your brake fluid level doing, are you loosing any, check at
>>> the wheel (slave) cylinders as well.
>>> Best of luck, John
>>> 1990 V8 Quattro
>>> On Sun, 27 Feb 2005 17:46:52 GMT, "Nadia" <frogmore89@hotmail.com>
>>> wrote:
>>>
>>>>Can anyone suggest a cure for my UK Audi 80, I am at my wits end.
>>>>When pressing the brake pedal, the pedal was occasionally going
>>>>nearly to the floor, when pumped twice it would be OK and the brake
>>>>pedal pressure would be fine for days, I replaced the master
>>>>cylinder with a new one from
>>>>Europarts UK and everything has been OK for a week, now the original
>>>>problem
>>>>has happened again, brake pedal will go to the floor and pumped
>>>>twice it will have a good brake pedal and the brake pedal pressure
>>>>would be OK, brake pedal pressure is good and when braking car does
>>>>not veer
>>>>from a straight line,
>>>> can anyone diagnose this problem as to why
>>>>brake pedal pressure keeps dropping from time to time? can't see any
>>>>leaks,
>>>>master cyl reservoir fluid level is not dropping
>>>>Ps my audi 80 1.9TDI avant has got ABS discs brakes all round, 1994
>>>>model.
>>>>Thanks
>>>>
>>>>
>>>
>>
>>
>
>