Brake pads

[Matt]

I think I generally am 18-24 months between pads, which is between 10 and 20k miles ish.

Ish.

[Phmode]

If my PR3/4's give less than 7,000 miles I would sell the bike.

If my pads ever needed changing I burn it.

[peterwbaker]

Interesting thread!

18K Service due next week and new pads all round as they down to the bottom of the groove - will go with OEM this time.

Rear PR4/Roadtec01 tyres on average just over 5K and 47 MPG all of which I am pretty happy with given the grin factor!

Peter

[TurboBevy]

Front pads now replaced which is a very straightforward job indeed thanks to the caliper pistons sliding back easily with the use of the special tool that is my big fat thumbs. Pads had just over 2mm of friction material remaining. Perhaps they were not brand new when I bought the bike in May last year? Rear pads were though, but I have history here as I use the back brake, a lot. 

Bit surprised that the BMW workshop manual makes no mention of reapplying thread locker to the brake caliper bolts, but then I only removed them as it makes the job easier and caliper cleaning more thorough.

Money spent on brakes & tyres is never money wasted. 

[Phmode]

And no one ever got fired for buying OEM 

[paulotex]

Great thread, I'm glad it was revived recently.

I got a 2010 K1300R a month ago, with 22k miles. I suspect I need a new rear disk, and so I'll be getting some new pads too. I was thinking I would go for:

Rear disk: Brembo Oro Part # 68.B407.C0
https://www.sportsbikeshop.co.uk/motorcycle_parts/content_prod/400195


Rear pads: Brembo Organic(?)
https://www.bmw-motorrad-bohling.com/uk/bmw-brake-pads-back-for-k1200s-k1200r-k1200r-sport-k1300r-k1300s.html

(Is this the OEM that you all have been mentioning?)

Is this the right combination?

Thanks.

PS:

And now some explanation why I think I need new pads:

The bike came with very little service history, unfortunately, so I took it to my local BMW to do a regular service. They warned me that the rear disk is a bit under spec (4.3 instead of 4.5mm), and that next time it will need replacement. However, I have noticed that the rear disk is always uncomfortably warm to the touch, even when the front disks are cool. I use the front brake more than the rear, so I find this strange. I already removed the rear caliper and cleaned it a bit. The pistons didn't seem stuck.

In addition, the rear disk does not seem straight when I slide it between my fingers, radially from the inside to the outside of the disk.

And that is why I suspect that there is a bit of warping, and that I might need to replace the rear disk.

[Phmode]

Disc warpage or run-out is one sure cause of an overheating disc, especially if you have freed the pistons and don't use it overly much. Most don't realise that the pads 'float' on the disc surface all the time, unless you get pad knock-back from a horrendous tank-slapper for instance, and so a warped disc will have them wobbling back and forth and getting hot in the process.

The arguments about which bits to buy will be going on long into the night but for my peace of mind and money I will always go for the genuine article from the nice Mr BMW.

[paulotex]

Just an update on replacing the rear disk and pads due to suspected warp/overheating:

I just went for a short ride with the new parts. After a 2 min ride at 60mph the rear disk is warm, but not uncomfortable. Previously, it would hurt to the touch after just 2 minutes of riding at 60 mph. Now it is simply warm. The front disk is still a bit cooler though. I will leave this for now, but will keep checking, specially after a few spirited longer runs.

[Phmode]

Did you do anything about the pistons? Did I miss it?

[paulotex]

When I removed the caliper, I could not tell that the pistons were stuck. They moved. So I cleaned and lubed them a bit (copper paste). Last weekend I went for a 200 mile trip under the heat (100 mile round trip to the coast) and everything went well. The rear disk is warm, almost uncomfortable, but does not burn. Before, with the old disk, it would hurt if touched for more than 1/2 second. So I think there is some improvement there.

I am worried about the rear new pads, though. I did go for sintered ones, because although I read they should not be used for the front brakes, I thought they are ok for the rear. I am not so sure now anymore, and I worry they might score the rear disk.

Can anyone confirm that I can use these sintered pads on the rear:
https://www.sportsbikeshop.co.uk/motorcycle_parts/content_prod/396237

If the answer is no, I will replace them. Better that than destroying a new disk...

Thanks!

[TomL]

When I removed the caliper, I could not tell that the pistons were stuck. They moved. So I cleaned and lubed them a bit (copper paste). Last weekend I went for a 200 mile trip under the heat (100 mile round trip to the coast) and everything went well. The rear disk is warm, almost uncomfortable, but does not burn. Before, with the old disk, it would hurt if touched for more than 1/2 second. So I think there is some improvement there.

I am worried about the rear new pads, though. I did go for sintered ones, because although I read they should not be used for the front brakes, I thought they are ok for the rear. I am not so sure now anymore, and I worry they might score the rear disk.

Can anyone confirm that I can use these sintered pads on the rear:
https://www.sportsbikeshop.co.uk/motorcycle_parts/content_prod/396237


If the answer is no, I will replace them. Better that than destroying a new disk...

Thanks!

You should not lube the pistons with copper paste. It might even bugger up the seals and piston rubber dust seals.

If you want to free off the pistons you can put a drop of brake fluid on the protruding piston and allow it to run down into the calliper body. Ease the piston in and carefully pump it out a few times cleaning the piston when it is out.

[stevel]

+1 on what Tom said - copper grease is a big no-no here. It will swell the seals, making them stiffer and adding to your problems. Worse, it could degrade the seals enough to cause them to fail under pressure. Not likely, but possible. Not a risk I'd want to take.

The correct product to lubricate pistons with is either a bit of brake fluid, although that doesn't last long, or some red rubber grease ( specially formulated not to harm rubber seals).

Reading back, your problem may well be that the seals have gone anyway, and aren't pulling the pads back from the disc as they should. Given the copper grease contamination, I would opt for a full overhaul of the calipers, with new seals. After that your brakes should work like new.

Steve

[Phmode]

And then I get some flak occasionally for saying only buy a K with a full dealer service history...

If you don't know how your bike works, take it to someone who does.

To enlarge on what Steve said about the seals, piston seals are designed to 'flex' when the brakes are applied, stretching outward ever so slightly. When you release the pressure, the seals return to their 'normal' shape and position in the groove, taking the piston back with them ever so slightly and if it works, this link shows you in a piccie...

https://goo.gl/images/TNLqeU

There are tons of images and good videos on the web showing how to do stuff properly, so please, either do it the right way or take it to someone who knows how, we can't afford to lose members to brake failure and make sure that you get the caliper stripped, cleaned and new seals fitted and if the pistons are corroded in the seal 'swept' area after a good clean up, then new pistons are in order too.

[black-k1]

And then I get some flak occasionally for saying only buy a K with a full dealer service history...

If you don't know how your bike works, take it to someone who does.

To enlarge on what Steve said about the seals, piston seals are designed to 'flex' when the brakes are applied, stretching outward ever so slightly. When you release the pressure, the seals return to their 'normal' shape and position in the groove, taking the piston back with them ever so slightly and if it works, this link shows you in a piccie...

https://goo.gl/images/TNLqeU

There are tons of images and good videos on the web showing how to do stuff properly, so please, either do it the right way or take it to someone who knows how, we can't afford to lose members to brake failure and make sure that you get the caliper stripped, cleaned and new seals fitted and if the pistons are corroded in the seal 'swept' area after a good clean up, then new pistons are in order too.

Just to give the other side of the picture

My K1300Ss have both been fully dealer serviced. After one such service, I picked up the bike, met with a friend and we then picked up my two sons for a long weekend in France looking at WW1 and WW2 sites. As I pulled off the A12 onto the M25 slip road, with my eldest son on the pillion, having been travelling at ... er ... speed, I slowed for the trafic lights on the round about and applied some brake. The lever came back to the bars and nothing happened. (Luckily I always use foot brake as well so slowing was done on the rear.) I pulled over to find the right hand front caliper swinging freely from the end of the brake line and totally separate to the "fork leg".  The new brake pads had been fitted correctly without the wrong type of grease but the caliper mounting bolts had not seen a torque wrench!

Just make sure you take your bike to someone who knows what they're doing!

[Blobby]

and just to throw another angle to this. Before setting off make sure your vehicle is roadworthy, lights etc. and if on a long journey have a look over all the components like axle bolts, chain slack (where fitted) and anything thing else you rely on..

and before you ask other than lights and do the wheels go round and tyres have no nails in them, I don't check anything i get on and ride mainly because i do all my own maintenance and my OCD prevents such errors, but yes the dealer should have checked the calliper bolt torques etc. and would be getting a very angry person in their showroom shouting from the roof tops if it were me.