Just got my Brembo caliper rebuild kits from the dealer. In the kit is a thin package of KLUBER lube for the seals.
I have to assume that it is compatible with DOT 4 but I'm not sure. I have always used DOT 4 as my assembly lube. Also in the kit is the two seals that go between the caliper halfs.
I have rebuilt dozens of brake calipers for cars trucks and bikes but have never yet cracked any open having been told by older mechanics "don't go there, not worth the hassle, those seals almost never fail"
What do you guys think about this assembly lube and cracking calipers in half?
Thanks,
Chris

First, in order to extract the pistons you don't have any other option than opening the calipers. The O'rings sealing the 2 parts are static and don't wear, but they could dry. This is a no brainer... replace them.
The lube provided by BMW in their kit in DOT 4 compatible.

I just use compressed air to blowout the piston out, never seperated a caliper yet.

I think you will find a tutorial from Ned detailing the procedure.

http://k100rt.aforumfree.com/tutorial-f17/rear-brembos-service-t1065.htm

Let me chime in here. I will always split the calliper because it is very easy to do and it gives you a chance to replace those tiny o rings which are very flat and hard by now.

It also gives you a chance to inspect the cylinders and pistons close up because you will definitely need to clean them up. I've dropped all the bits in a bucket of hot water with some dish wash detergent.

The grease is very thick in consistency and very slippery. It makes the assembly easy.

BTW the trick is to crack all bolts and connections including bleed nipples before you remove the calliper.

Don't forget to torque everything to specs.

Best to do this when SWMBO goes out and pop the bits into the dish washer just make sure she is not coming home in time to see them in there. Alternatively rally hot waters scrubbing and detergent is the best way to clean brake bits up really well. Finish off with a good rinse in boiling water and shake/blow as much water as you can out of all crevices. Being boiling hot makes sure they really dry well. I know Tom Cutter does not recommend splitting the two halves.
Regards,
K-BIKE

K-BIKE wrote:... I know Tom Cutter does not recommend splitting the two halves.
Regards,
K-BIKE

Any idea why? I ask because I am close to servicing the front brakes/forks.

I have split callipers on rally cars to fit spacers for to use vented discs. You end up with O rings each side of the spacer. Never had a problem with them.

Hi, all.

I had some squealy, 'draggy' brakes so I too bought and used the Brembo kit. Ned mentioned above that it's smart to start the screws out when the caliper is still on the bike. That's a smart tip I wish I had heard before I serviced my caliper. javascript:emoticonp('')
Anyway, the Kluber grease and new seals helped immensely, as did the thorough cleaning I gave the parts. It ended the squeal and the brake works fine now. Clymer manual instructions were helpful.

Bob

Hi Ned and All,
From what I recall of reading a bunch of exchanges on the subject of to split or not to split was that some callipers distort when bolted together and when separated they may not rejoin absolutely leak free.

Most car calliper rebuild instructions sternly warn not to split but they never (that I have seen anyway say why).

So where does that leave me in the split or not debate. If the calliper one is thinking about splitting has O rings available to go between the faces I cannot see a problem with separating them but if the calliper does not have O rings available I would not split them unless I absolutely could not avoid it.

This is because as was remarked above after 20 odd years the rubber in the O ring will be pretty stuffed as far as rebound elasticity is concerned I suspect hence may not seal properly when clamped back in a slightly different position.

So given I had the O rings to go between the faces as well as the rest of the seals I suspect I would probably split them if only because it enables one to microscopically check all parts of the bore really easily. I think I would be inclined to make sure that the piston went back into the same bore it came out of though (with a new seal of course).

Brake rebuild on our car brake systems always used to recommend that rubber grease was used but buying it was about as simple as buying billets of unobtanium or litres of mouse milk. But with Teutonic thoroughness the BMW kit comes with the grease and is well worth using.

In all seriousness the concept of replacing all of the old rubber bits in the brake system including hoses is a very wise thing since we or at least I tend to spend a lot of time concentrating on making sure the bike can and will go. However arguably the stopping bit is a wee bit more important especially as we are straddling a bike which will give a Porsche a run for its money in acceleration and with the 16 Valve is capable of over 140 mph and that is a heck of a lot of momentum to shed especially if one has to do it in an emergency.
Regards,
K-BIKE