Hi All,
          Apologies if this topic was covered before, but I think my front Brembo brake pistons/seals are leaking. I have noticed a very light "spray" around the front wheel rims of late and suspect the seals are perished. My question: is this a relatively easy job to replace the seals and pistons? Must I split the callipers in half? Any other pitfalls to be aware of??

Many thanks

Trapper

Easy job
If you know what you are doing
If not: look for soemeone who has done that befor

Get the relapair kit 2x
And.... do the brake overhaul once but complete
Incl new hoses and cleaning the pump

I don't know whether it's possible to get the pistons out without splitting the caliper halves.

What I do know is that getting both pistons per side out is tricky - an air line will push the out the one nearest to the brake fluid gallery leaving one in place.

That said, I was dealing with seized pistons.

What I would do is to remove one pad, hold the remaining one (or a suitably thin piece of wood) between the pistons while they are still attached to the brake lines. Then operate the brake lever to push the pistons out partially (far enough to be able to grip them later).

With the calipers split you should be able to pull the pistons out (especially if the seals are failing).

As you've probably already found Trapper, the four-piston seal kit includes new pistons so as long as you don't damage the caliper you can be fairly brutal with the old ones.

Splitting the calipers is not really an issue, getting the screws out might be after so many years. Just be certain that the mating surfaces are clean when you reassemble the caliper halves. I use a smear of red brake grease to hold the o-rings in place during reassembly.

Hi All,
          Enormous thanks for your very helpful comments - much appreciated.

Best wishes
Trapper

I have found that so long as you dont damage the old pistons they will be ok. They are hard anodized aluminium so dont grab them with pliers or it will be like glass splintering and a big chip comes off.
I have done 2 sets and both times had to split them to make it easy to get them out with compressed air.
Use a big wad of rag don't try to just hold your hand to catch them if they come out fast they will hurt to say the least.

If you blow the piston/s out with compressed air, place it in a plastic bag and this will stop crap spraying everywhere.  Or rags as Rick suggests.  Or maybe in a box, or ....

Thanks Guys - I think I should put in an order for a bullet proof vest while I'm at it 

Trapper

Hi I have had trouble resealing after splitting them and I now change the seals without splitting its fairly easy hardest part is getting the piston out a bit of compressed air works just be careful they can pop pretty hard. AB

Brake kit number 34112331631 is £55.80 from Motorworks or Motobins, that works out at €66, plus potage and packing.
Went into the BMW dealer in my local town and asked for a price - €61! Ordered two kits and they will be here next week, no postage charge.
Money saved, thank you BMW.

Trapper

Pm sent re caliper kits

Hi,
        Enormous thanks for the heads-up on these. Unfortunately I got sorted last week  Hopefully there will be several members very interested in this offer.
Still looking for a K1 (not the Black version) Tank Bag - that will not mean flogging the house for it. The one currently on Ebay is way over-priced.

Trapper

ausbrick wrote:Hi I have had trouble resealing after splitting them and I now change the seals without splitting its fairly easy hardest part is getting the piston out a bit of compressed air works just be careful they can pop pretty hard. AB

Have been watching this thread with interest,I recently bought a 1990 K100rs 16v with the same front brake calipers.I found the front caliper pistons were sticking but the 2 long allen bolts holding the calipers together totally immovable,although I managed to get them useable by working pistons in and out etc,I am pleased to find piston removal without splitting is possible: thank you! Shame it only seems possible to buy seals together with pistons