I changed all my discs/ pads after suffering low speed pulsing. 
The original rear brake pulsed as well as the fronts.
 Not a happy bunny..... low speed pulsing is back again, although the new rear disc is good, so just the front .
The front wheel doesnt appear to be out, but I need to borrow  a dial gauge.
The front brake action is very grabby. Hopefully two caliper kits and fresh fluid will cure it. Will check the brake lever pivot arm. The pulsing is very annoying, its like one side is braking then the other. 
Is there anyway the ABS system could be "Pulsing ". The Red lamp goes out when i apply the brakes as it should. 
Any other ideas?
Bob

just tape a piece of plastic to the frt fork and have it touch the disc.
then rotate the wheel. should be obvious if you rotor is warped.
i use the handle of a cheap plastic kid's paintbrush.

Hi Kartoo,
not sure of the chances of a new disc being warped, but I guess it can happen, they are floating discs which I had hoped would be better. I will set the wheel on stands and check disc runout and the wheel itself. I will also check the alignment of the forks too. I have a new set of non sintered ebc pads so will try them to see if the effect is reduced. The HH sintered pads are very grabby. Caliper seal kits have been ordered,will then check the master cylinder seals and hoses. Cannot expect to have no niggles on a 25 year bike, but seems a lot of people have experienced this and has taken a lot of time/ money to cure it.
Happy days.....

I cannot imagine that this problem has anything to do with the ABS system.  If the problem cannot be solved, then it may be ameliorated by removing the bolts and rotating one disc with respect to the other and then retightening things.  That changes the phases of the pulsing of the two discs, and may help to cancel out the worst of it.

when you fitted the new disc was everything very clean where the disc bolts on, possibly not seated completely to wheel making the disc slightly out of true.

HI Guys thanks for both replies.
I guess the ABS being at fault was a long shot. Seems as though the fault has transferred to the new discs. I shall have the unit on the bench later so will check both discs and wheel for run out. I will try moving one disc around its hub fixing at a time to see if the effect is reduced, that is a good idea. Pen and paper at the ready.
Both sets of new sintered pads have a nice even contact on them . They are very grabby , not something I am used to. I do have an unused set of non sintered ebc pads, so may try them at some point.
I did make sure everything was clean prior to assembly, I may try and check for run out where  the disc sits the on the hub.The spindle seems to be ok. The front wheel bearings do have very slight movement, will change them too. The fork action is very harsh, as if there is too much fluid in there. Will drain out measure quantities, and refill with correct amount.
Better get on with the rear caliper overhaul before I move onto the fronts. Happy days
Bob

Anyone know the torque setting for the caliper body to body  bolts before i bolt her up, and why only one seal in the repair kit?

audibob wrote:Anyone know the torque setting for the caliper body to body  bolts

30 Nm +/- 5 Nm.

Only 1 seal?.......it should be 2 of each of the 3 different seals in the set.

Thanks Inge, 
I think I read someone else commented on only getting one "O" ring.  He found the correct type and size so will find the thread and order  some spares .

O-ring : 6,6 x 1,8 mm

Thanks Inge,
I will phone moterwerks uk and ask why the repair kit contained only one 0 ring.

Busy day.
Rotated discs around the hub, but pulsing constant.
 Fork oils drained ( 330ml) and refilled with 300ml which has made the front end nicer. Upper and lower leg bolts replaced, someone must have used an english set on this bike..just had enough grip to remove them. 
Front brake fluid changed. Inspected both front calipers for piston movement, and found someone had tried to get one out with a pair of molegrips, the face that pushes the pad was really chewed up, why would anyone do this??. I wonder whether the chewed piston may be pushing the pad out of line slightly,  to create the pulsing. I need to remove it and see if the face is still flat.
 Most of the seals were a yellow colour, would these be original or just age related
 I will probably end up replacing the front pistons and seals . 
I have fitted a new set of non sintered ebc pads for the time being. 
Next weekend will be a more in depth look at the wheel, and see if the disc seat hubs are true, and the new discs of course.
Good fun....

The 'yellow' dust seals sound like the (better) silicon seals. The black ones are not so heat resistant.

Paul.

Thanks Paul, I was beginning to wonder how old my bike really is....

After fitting the non sintered pads,  there is feel to the front brakes again, too early to say but doesnt seem be any pulsing. I intend to remove the front pistons, fit new seals, and  replace the damaged piston with the  good one from my rear caliper, which will have two new ones. If the front hoses are original, and they probably are, then as everyone suggests that they might be collapsing, will change those too. 
Will  check the wheel for straightness too , not quite like painting the Forth road bridge......but seems never ending at the moment, all part of the fun I keep telling myself, cant wait the change the head bearings...
infamy infamy its got it in for me...

I keep telling myself, cant wait the change the head bearings...
infamy infamy its got it in for me...

If you are also a full member of the BMW Club (UK), then they have a Tool Hire service. It includes a suitable slide hammer extractor for the bearing cups, so the job is easy.

Mike

HI Mike,
 thanks for that info, anything to make the job easier.
Bob

Stripped both front Calipers, cleaned , red rubber grease on  seals and  pistons etc, refitted and bled. I decide to refit the HH sintered pads again .  Checked both calipers for actuation and retraction when I released the brake lever, and found all pistons acting  together.
The brake action is now much smoother, very positive due to using the HH pads again, with only a slight hint of any pulsing.  Must have done something right!!
There is slight play at the brake lever before actuation, but this may be normal. I can certainly get her nose diving just using two fingers on the lever...So for the time being I am happy. 
I will check the wheel itself at some point.
Now where was I with the list "to do"
Bob

As a side point, sintered pads are known for giving less 'feel' but better braking