brake system question (Disco 200Tdi)

People Hi,

I would be grateful to have your input on the following problem.
The car is a 1994 evented Camel Trophy Discovery 200Tdi with 82.000 Km on
its clock.

Over the last few days I have noticed that when I press the brake pedal more
than three times one after another it appears like the brake pedals gets a
"bricky" feel. And it does need far more strength from my foot to stop the
car.

I have just changed the brake pump but I fear that the servo is damaged.
While changing the brake pump yesterday I noticed that while removing the
old pump from the servo there was a very strong hiss from the servo. Was
this due to leakage from the servo's diaphragm which cause the loss of
assistance to the pump and therefore the "bricky" feel when I step on the
brakes repeatedly over a very short time?

I will also be changing the pads because they must be on their way out.

Thanks for your input
Pantelis

In message <[email protected]>
"Pantelis Giamarellos" <[email protected]> wrote:

> People Hi,
>
> I would be grateful to have your input on the following problem.
> The car is a 1994 evented Camel Trophy Discovery 200Tdi with 82.000 Km on
> its clock.
>
> Over the last few days I have noticed that when I press the brake pedal more
> than three times one after another it appears like the brake pedals gets a
> "bricky" feel. And it does need far more strength from my foot to stop the
> car.
>
> I have just changed the brake pump but I fear that the servo is damaged.
> While changing the brake pump yesterday I noticed that while removing the
> old pump from the servo there was a very strong hiss from the servo. Was
> this due to leakage from the servo's diaphragm which cause the loss of
> assistance to the pump and therefore the "bricky" feel when I step on the
> brakes repeatedly over a very short time?
>
> I will also be changing the pads because they must be on their way out.
>
> Thanks for your input
> Pantelis
>
>

It certainly sounds like you are losing vacuum somewhere. Normally
the vacuum pump can keep up, but as you have aleady replaced that
it would be reasonably safe to assume that the problem is either
the plumbing or the servo. If the servo was completely knackerd
(they tend to either work or not) then, with your foot on the
brake, starting the engine the pedal will not go down a bit as
it should. Before condemming the servo, check there are no leaks
in the vacuum pipe, or the joints.

Richard

--
www.beamends-lrspares.co.uk [email protected]
RISC-OS - Where have all the good guys gone?
Boycott the Yorkshire Dales - No Play, No Pay

On or around Wed, 10 May 2006 07:44:33 +0300, "Pantelis Giamarellos"
<[email protected]> enlightened us thusly:

>People Hi,
>
>I would be grateful to have your input on the following problem.
>The car is a 1994 evented Camel Trophy Discovery 200Tdi with 82.000 Km on
>its clock.
>
>Over the last few days I have noticed that when I press the brake pedal more
>than three times one after another it appears like the brake pedals gets a
>"bricky" feel. And it does need far more strength from my foot to stop the
>car.
>
>I have just changed the brake pump but I fear that the servo is damaged.
>While changing the brake pump yesterday I noticed that while removing the
>old pump from the servo there was a very strong hiss from the servo. Was
>this due to leakage from the servo's diaphragm which cause the loss of
>assistance to the pump and therefore the "bricky" feel when I step on the
>brakes repeatedly over a very short time?

sounds like lack of vacuum. Pump is the obvious candidate, which you've
changed. Try pressing the pedal before starting the engine when it's been
standing a while - the servo should still have some vacuum. If you get
full-on brick mode then it sounds like an air leak into the servo.

Is it losing brake fluid?
--
Austin Shackles. www.ddol-las.net my opinions are just that
If all be true that I do think, There are five reasons we should drink;
Good wine, a friend, or being dry, Or lest we should be by and by;
Or any other reason why. - Henry Aldrich (1647 - 1710)

beamendsltd wrote:
> In message <[email protected]>
> "Pantelis Giamarellos" <[email protected]> wrote:
>
>> People Hi,
>>
>> I would be grateful to have your input on the following problem.
>> The car is a 1994 evented Camel Trophy Discovery 200Tdi with 82.000
>> Km on its clock.
>>
>> Over the last few days I have noticed that when I press the brake
>> pedal more than three times one after another it appears like the
>> brake pedals gets a "bricky" feel. And it does need far more
>> strength from my foot to stop the car.
>>
>> I have just changed the brake pump but I fear that the servo is
>> damaged. While changing the brake pump yesterday I noticed that
>> while removing the old pump from the servo there was a very strong
>> hiss from the servo. Was this due to leakage from the servo's
>> diaphragm which cause the loss of assistance to the pump and
>> therefore the "bricky" feel when I step on the brakes repeatedly
>> over a very short time?
>>
>> I will also be changing the pads because they must be on their way
>> out.
>>
>> Thanks for your input
>> Pantelis
>>
>>
>
> It certainly sounds like you are losing vacuum somewhere. Normally
> the vacuum pump can keep up, but as you have aleady replaced that
> it would be reasonably safe to assume that the problem is either
> the plumbing or the servo. If the servo was completely knackerd
> (they tend to either work or not) then, with your foot on the
> brake, starting the engine the pedal will not go down a bit as
> it should. Before condemming the servo, check there are no leaks
> in the vacuum pipe, or the joints.
>
> Richard

Does this one have a vacuum pump on the back of the altenator? I wonder if that
could keep up as well as an induction manifold connection?

--
"He who says it cannot be done would be well advised not to interrupt
her doing it."

The fiend of my fiend is my enema!

pantellis .

i have just changed the servo unit on my 90 defender[ 300tdi ] .

i had same problem as you, i could also hear a hiss when i switched
engine off but couldnt find where it came from .

in the end i put a pipe into the servo hole and blew air into it, and
with some soapy water i found that the servo casing was cracked just
next to the mounting points for the master cylinder studs .

i have the large diameter and thin servo unit which is fitted to all
300tdis .

on the servo front there is a 125mm diameter circle , which the master
cylinder sits on , and on the edges of the circle just to each side of
the mounting studs mine was cracked , where the bend in the plate of
the casing is .

it is all caused by the brake cylinder weight and bouncing up and down
when driving which makes the servo case crack in these 2 places .

if you replace servo then also change the master cylinder at same time
..


servo is easy to change , its just a little fiddly to remove the pin in
the rear fork of servo , dont drop pin into the hole .

you do not need to remove the pedal box, the master cylinder and servo
will come off from the front .

remember that there is an O-RING on the master cylinder to seal it
when fitted to servo .


mine now brakes very well .

Richard thanks.

I will perform the foot on brake pedal while starting the engine test and
then check the "plumbing" for leaks.

Thanks again
Pantelis

"beamendsltd" <[email protected]> wrote in message
news:9088b7244e%[email protected]...
> In message <[email protected]>
> "Pantelis Giamarellos" <[email protected]> wrote:
>
> > People Hi,
> >
> > I would be grateful to have your input on the following problem.
> > The car is a 1994 evented Camel Trophy Discovery 200Tdi with 82.000 Km
on
> > its clock.
> >
> > Over the last few days I have noticed that when I press the brake pedal
more
> > than three times one after another it appears like the brake pedals gets
a
> > "bricky" feel. And it does need far more strength from my foot to stop
the
> > car.
> >
> > I have just changed the brake pump but I fear that the servo is damaged.
> > While changing the brake pump yesterday I noticed that while removing
the
> > old pump from the servo there was a very strong hiss from the servo. Was
> > this due to leakage from the servo's diaphragm which cause the loss of
> > assistance to the pump and therefore the "bricky" feel when I step on
the
> > brakes repeatedly over a very short time?
> >
> > I will also be changing the pads because they must be on their way out.
> >
> > Thanks for your input
> > Pantelis
> >
> >
>
> It certainly sounds like you are losing vacuum somewhere. Normally
> the vacuum pump can keep up, but as you have aleady replaced that
> it would be reasonably safe to assume that the problem is either
> the plumbing or the servo. If the servo was completely knackerd
> (they tend to either work or not) then, with your foot on the
> brake, starting the engine the pedal will not go down a bit as
> it should. Before condemming the servo, check there are no leaks
> in the vacuum pipe, or the joints.
>
> Richard
>
> --
> www.beamends-lrspares.co.uk [email protected]
> RISC-OS - Where have all the good guys gone?
> Boycott the Yorkshire Dales - No Play, No Pay

Thanks to everybody for providing your valued input on this case.

I have just performed the test and the brake pedal does go down when I start
the engine. In fact it progressively goes down as long as I keep my foot
pressing the brake pedal.

It also has some travel when the engine is switched off. It goes up and
gets harder upon the second and third pressing (with the engine switched
off)

BUT those tests revealed that my second camel does have a problem since the
brake pedal is rock hard when the engine is switched off.
The pedal goes down when I start the engine though. So the secondhand one
(in very good condition bought from a friend here in Greece) I bought will
be useful.

Thanks again.
Pantelis



"m0bcg" <[email protected]> wrote in message
news:[email protected]...
> pantellis .
>
> i have just changed the servo unit on my 90 defender[ 300tdi ] .
>
> i had same problem as you, i could also hear a hiss when i switched
> engine off but couldnt find where it came from .
>
> in the end i put a pipe into the servo hole and blew air into it, and
> with some soapy water i found that the servo casing was cracked just
> next to the mounting points for the master cylinder studs .
>
> i have the large diameter and thin servo unit which is fitted to all
> 300tdis .
>
> on the servo front there is a 125mm diameter circle , which the master
> cylinder sits on , and on the edges of the circle just to each side of
> the mounting studs mine was cracked , where the bend in the plate of
> the casing is .
>
> it is all caused by the brake cylinder weight and bouncing up and down
> when driving which makes the servo case crack in these 2 places .
>
> if you replace servo then also change the master cylinder at same time
> .
>
>
> servo is easy to change , its just a little fiddly to remove the pin in
> the rear fork of servo , dont drop pin into the hole .
>
> you do not need to remove the pedal box, the master cylinder and servo
> will come off from the front .
>
> remember that there is an O-RING on the master cylinder to seal it
> when fitted to servo .
>
>
> mine now brakes very well .
>

The vacuum pump is on the engine's side, not on the back of the alternator.

Take care
Pantelis

"GbH" <[email protected]> wrote in message
news:[email protected]...
> beamendsltd wrote:
> > In message <[email protected]>
> > "Pantelis Giamarellos" <[email protected]> wrote:
> >
> >> People Hi,
> >>
> >> I would be grateful to have your input on the following problem.
> >> The car is a 1994 evented Camel Trophy Discovery 200Tdi with 82.000
> >> Km on its clock.
> >>
> >> Over the last few days I have noticed that when I press the brake
> >> pedal more than three times one after another it appears like the
> >> brake pedals gets a "bricky" feel. And it does need far more
> >> strength from my foot to stop the car.
> >>
> >> I have just changed the brake pump but I fear that the servo is
> >> damaged. While changing the brake pump yesterday I noticed that
> >> while removing the old pump from the servo there was a very strong
> >> hiss from the servo. Was this due to leakage from the servo's
> >> diaphragm which cause the loss of assistance to the pump and
> >> therefore the "bricky" feel when I step on the brakes repeatedly
> >> over a very short time?
> >>
> >> I will also be changing the pads because they must be on their way
> >> out.
> >>
> >> Thanks for your input
> >> Pantelis
> >>
> >>
> >
> > It certainly sounds like you are losing vacuum somewhere. Normally
> > the vacuum pump can keep up, but as you have aleady replaced that
> > it would be reasonably safe to assume that the problem is either
> > the plumbing or the servo. If the servo was completely knackerd
> > (they tend to either work or not) then, with your foot on the
> > brake, starting the engine the pedal will not go down a bit as
> > it should. Before condemming the servo, check there are no leaks
> > in the vacuum pipe, or the joints.
> >
> > Richard
>
> Does this one have a vacuum pump on the back of the altenator? I wonder if
that
> could keep up as well as an induction manifold connection?
>
> --
> "He who says it cannot be done would be well advised not to interrupt
> her doing it."
>
> The fiend of my fiend is my enema!
>
>

On or around Thu, 11 May 2006 10:22:22 +0300, "Pantelis Giamarellos"
<[email protected]> enlightened us thusly:

>It also has some travel when the engine is switched off. It goes up and
>gets harder upon the second and third pressing (with the engine switched
>off)

that's normal. what happens if you leave it for say half an hour or and
hour, then press the pedal without having started the engine? You should
get some residual vacuum in the servo - if the servo is leaking you'll get a
hard pedal almost immediately.

depending on the brake system, you exhaust the servo vacuum in anything from
about 2 to 5 brake applications.
--
Austin Shackles. www.ddol-las.net my opinions are just that
"There is plenty of time to win this game, and to thrash the Spaniards
too" Sir Francis Drake (1540? - 1596) Attr. saying when the Armarda was
sighted, 20th July 1588

Austin Hi,

It does go down with the engine switched off for several hours.
And it does give about three brake applications before the pedal gets this
"bricky" feel.
So I guess the 1994 Disco is OK.

Testing revealed that the 1993 one does have a faulty servo though.

Thanks to everybody for helping into sorting this out

Take care and have a nice weekend
Pantelis

"Austin Shackles" <[email protected]> wrote in message
news:[email protected]...
> On or around Thu, 11 May 2006 10:22:22 +0300, "Pantelis Giamarellos"
> <[email protected]> enlightened us thusly:
>
> >It also has some travel when the engine is switched off. It goes up and
> >gets harder upon the second and third pressing (with the engine switched
> >off)
>
> that's normal. what happens if you leave it for say half an hour or and
> hour, then press the pedal without having started the engine? You should
> get some residual vacuum in the servo - if the servo is leaking you'll get
a
> hard pedal almost immediately.
>
> depending on the brake system, you exhaust the servo vacuum in anything
from
> about 2 to 5 brake applications.
> --
> Austin Shackles. www.ddol-las.net my opinions are just that
> "There is plenty of time to win this game, and to thrash the Spaniards
> too" Sir Francis Drake (1540? - 1596) Attr. saying when the Armarda was
> sighted, 20th July 1588