Pulsing Brakes

Hi all,

Got a brake problem with a 1986 90. I know it is
my fault but have no idea how to sole it!

I recently upgraded to stainless steel brake
hoses, new drums & shoes (new springs too), and
new pads on the front.

Having made the changes I used a pressure bleeding
system. Lots of air and much crud was removed.
About a litre and a half of fluid passed through
the system.

The brakes are working fine - but the pedal, when
pressed 'hard' pulses. I assume that this is air.
Bled the system again but no air seen. Still
pulsing so bled again. This time with lots of
pumps of the brake pedal as well as the pressure
bleeder. Again no air removed - just good clean
fluid running through the system.

Brake pedal still 'pulses' under heavy braking -
Land Rover stops with wheels locked and in a
straight line. Light braking has no pulsing effect.

I'd appreciate suggestions on how to remedy this
problem.....

Regards

Richard

RichardB wrote:

>
> Hi all,
>
> Got a brake problem with a 1986 90. I know it is my fault but have no
> idea how to sole it!
>
> I recently upgraded to stainless steel brake hoses, new drums & shoes
> (new springs too), and new pads on the front.
>
> Having made the changes I used a pressure bleeding system. Lots of air
> and much crud was removed. About a litre and a half of fluid passed
> through the system.
>
> The brakes are working fine - but the pedal, when pressed 'hard' pulses.
> I assume that this is air. Bled the system again but no air seen. Still
> pulsing so bled again. This time with lots of pumps of the brake pedal
> as well as the pressure bleeder. Again no air removed - just good clean
> fluid running through the system.
>
> Brake pedal still 'pulses' under heavy braking - Land Rover stops with
> wheels locked and in a straight line. Light braking has no pulsing effect.
>
> I'd appreciate suggestions on how to remedy this problem.....
>
> Regards
>
> Richard

Richard - could you define your meaning of 'pulses'?

Do you mean that the pedal feels a bit spongy when pressed or are you
saying that when held stationary something is pushing the pedal back at you?

Does it only happen when you are braking with the wheels turning?

The front discs I assume are the originals and have not been
repositioned on the hubs.

RichardB wrote:

>
> Hi all,
>
> Got a brake problem with a 1986 90. I know it is
> my fault but have no idea how to sole it!
>
> I recently upgraded to stainless steel brake
> hoses, new drums & shoes (new springs too), and
> new pads on the front.
>
> Having made the changes I used a pressure bleeding
> system. Lots of air and much crud was removed.
> About a litre and a half of fluid passed through
> the system.
>
> The brakes are working fine - but the pedal, when
> pressed 'hard' pulses. I assume that this is air.
> Bled the system again but no air seen. Still
> pulsing so bled again. This time with lots of
> pumps of the brake pedal as well as the pressure
> bleeder. Again no air removed - just good clean
> fluid running through the system.
>
> Brake pedal still 'pulses' under heavy braking -
> Land Rover stops with wheels locked and in a
> straight line. Light braking has no pulsing effect.
>
> I'd appreciate suggestions on how to remedy this
> problem.....
>
> Regards
>
> Richard

If by pulsing you mean a rhythmic pushing against your foot when braking,
this will not be related to air in the system. It is usually due to damaged
or distorted discs or drums. (could be only one, and could be front or
back)
JD

"RichardB" <rDOTbush@btconnectDOTcom> wrote in message
news:[email protected]...
>
> Hi all,
>
> Got a brake problem with a 1986 90. I know it is my fault but have no idea
> how to sole it!
>
> I recently upgraded to stainless steel brake hoses, new drums & shoes (new
> springs too), and new pads on the front.
>
> Having made the changes I used a pressure bleeding system. Lots of air and
> much crud was removed. About a litre and a half of fluid passed through
> the system.
>
> The brakes are working fine - but the pedal, when pressed 'hard' pulses. I
> assume that this is air. Bled the system again but no air seen. Still
> pulsing so bled again. This time with lots of pumps of the brake pedal as
> well as the pressure bleeder. Again no air removed - just good clean fluid
> running through the system.
>
> Brake pedal still 'pulses' under heavy braking - Land Rover stops with
> wheels locked and in a straight line. Light braking has no pulsing effect.
>
> I'd appreciate suggestions on how to remedy this problem.....
>
> Regards
>
> Richard

Sounds like warped rotors. Have them checked and/or recut. If replacing be
sure to use proper tightening sequencing, star pattern, and tighten to the
right torque spec.

On 2006-04-21, Jack <[email protected]> wrote:

> Sounds like warped rotors. Have them checked and/or recut. If replacing be
> sure to use proper tightening sequencing, star pattern, and tighten to the
> right torque spec.

Warped discs are quite probably a myth, I've met a few people
personally who've cleaned "warped" discs and measured them with proper
engineering gauges at small increments and found them to be within
tolerance once they've been cleaned. Have a quick read of the
following.

http://www.stoptech.com/tech_info/wp_warped_brakedisk.shtml

--
Blast off and strike the evil Bydo empire!

"RichardB" <rDOTbush@btconnectDOTcom> wrote in message
news:[email protected]...
>
> Hi all,
>
> Got a brake problem with a 1986 90. I know it is
> my fault but have no idea how to sole it!
>
> I recently upgraded to stainless steel brake
> hoses, new drums & shoes (new springs too), and
> new pads on the front.
>
> Having made the changes I used a pressure bleeding
> system. Lots of air and much crud was removed.
> About a litre and a half of fluid passed through
> the system.
>
> The brakes are working fine - but the pedal, when
> pressed 'hard' pulses. I assume that this is air.
> Bled the system again but no air seen. Still
> pulsing so bled again. This time with lots of
> pumps of the brake pedal as well as the pressure
> bleeder. Again no air removed - just good clean
> fluid running through the system.
>
> Brake pedal still 'pulses' under heavy braking -
> Land Rover stops with wheels locked and in a
> straight line. Light braking has no pulsing effect.
>
> I'd appreciate suggestions on how to remedy this
> problem.....
>
> Regards
>
> Richard

The first thing to do is to establish which brake is the troublesome one
which involves clamping each flexible pipe in turn to see which one removes
the fault when clamped whilst driving. As you have fitted stainless
flexibles then this makes things a little difficult as you will damage them
by clamping. You can disconnect and block each one in turn by refitting an
old rubber flexi with the clamp on that (or a pair of mole grips) and
carrying out the same test. Failing that just check that you have removed
all the rusty lumps from the discs before fitting new pads but I think it's
more likely that the new drums at the rear are not seated on the hubs
properly since these are the only ones you have replaced, so take them off
again and check. If you jack up each wheel in turn and spin them gently by
hand you may be able to feel a tight spot on one of them to identify the
problem. Finally you could also have a new drum which is faulty and you
could find this by putting the old one back on to see what happens and, if
so, send it back for a replacement.

HTH Martin

>>
>> Brake pedal still 'pulses' under heavy braking -
>> Land Rover stops with wheels locked and in a
>> straight line. Light braking has no pulsing effect.
>>
>> I'd appreciate suggestions on how to remedy this
>> problem.....
>>
>> Regards
>>
>> Richard
>
> The first thing to do is to establish which brake is the troublesome one
> which involves clamping each flexible pipe in turn to see which one removes
> the fault when clamped whilst driving. As you have fitted stainless
> flexibles then this makes things a little difficult as you will damage them
> by clamping. You can disconnect and block each one in turn by refitting an
> old rubber flexi with the clamp on that (or a pair of mole grips) and
> carrying out the same test. Failing that just check that you have removed
> all the rusty lumps from the discs before fitting new pads but I think it's
> more likely that the new drums at the rear are not seated on the hubs
> properly since these are the only ones you have replaced, so take them off
> again and check. If you jack up each wheel in turn and spin them gently by
> hand you may be able to feel a tight spot on one of them to identify the
> problem. Finally you could also have a new drum which is faulty and you
> could find this by putting the old one back on to see what happens and, if
> so, send it back for a replacement.
>
> HTH Martin
>
>

Hi All,

Thanks for all the replies. Pulsing - by that I
mean that the brake pedal is pushing back at my
foot as I apply pressure to it. It only does this
when I brake hard. Gentle braking does not cause
this. The pedal feels hard at all times.

The front pads were changed a couple of months ago
and no problems then so they can be eliminated
from the equation.

Noted that it is not likely to be air in the
system. So that eliminates the new brake hoses too.

So the culprit has to be the rear braking system -
New shoes and new drums at the same time as the hoses.

I've backed off the brake adjusters a couple of
times and spun the wheels - they spin freely.

The conclusion then is that one of the rear brake
drums is at fault - Action required then is to
remove drums and check them for seating and any
obvious distortion.

Finally is this an issue - If a drum is distorted
is it necessary to replace it?

I'll report back when I've done the checking.

Many thanks for the comprehensive replies and
pointers.

Regards

Richard