Caliper Overhaul.

[stuartb]

Seals and pistons should be delivered Mon/Tues.. thought I'd pop out caliper seals in the meantime...these wee picks are spot on.

Seals are square cross section so no chance of a **** up and subsequent messy bowel evacuation.

One thing I did notice, I expected the piston seal to be a closer fit on the piston (outside the pot) theres a noticeable gap, I'll check the new seals against the new pistons when they arrive.

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[stuartb]

Arrived today.....

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[Carsonr6]

Stuart do you have the part numbers just for the seals alone?

 

[stuartb]

Stuart do you have the part numbers just for the seals alone?

Rob, not sure of your build date... https://www.realoem.com/bmw/enUS/select?product=M&archive=0&series=

Jump on and use the drop downs.. I save the front page on my desktop so I just click, it takes me right to my model..

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[stuartb]

Great service direct from Germany OE ....this is where I got mine

https://www.kfm-motorraeder.de/cms/en/genuine-spare-parts/bmw-spare-parts?smode=modelselect

Had a super quick gander there couldnt spot a seal kit, but no doubt it will be there somewhere...

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[stuartb]

Cleaned and rebuilt calipers. Washed them down with clean Paraffin, washed in soapy water then blow dried thoroughly with compressed air before installing seals.

Seals slipped in very snugly, used a strong LED light and the blunt end of a pick to assist, theres no chance of inverting a seal, I tried to roll one in my fingers but it sprung back to its original form.

The Brembo mounting gel supplied is absolutely superb, I used the small plastic trays supplied to bathe the seals and pistons in preparation for mounting.

Had the luxury of sitting in my kitchen installing the seals and pads...



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[Flyingscotsman]

Nice write up Stuart. Thanks for posting.

The calipers look like new!

 

[stuartb]

I'm looking to improve the performance of my brakes Rob, I've felt them degrade over the last few years...I thought new seals, pistons, fluid and pads would be a reasonable gamble, oh and new discs fitted a few thou ago...all of this in effect bringing that part of the system back to as new... hope I notice the difference...

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[stuartb]

Used about 400 mil of fluid purging those lines and calipers....feel as though if I have a good "pedal" !..... good lever just doesn't sound right does it ?.. so we'll wait and see how they perform...

Get the impression these pads are pretty grippy even by just spinning the wheel and applying moderate pressure...

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[DrIoannis]

Did you use GS911 to bleed the brakes. I found out that it was the only way (and official BMW service) to get all the air out of the system.

 

[stuartb]

I dont have one, thats interesting.... how does that work then ? Hmmmm Rob Carsons just bought one lol

I'll look up the user instructions, are they online ?


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[Flyingscotsman]

The GS-911Pulses the ABS system so that you flush out all the fluid in the ABS pump/valves. Provided you don’t have any air in the ABS pump a manual bleed should be OK but you will still have some old fluid in the ABS pump that will come out in use. If you can get hold of GS911 worth a go. I’ve done both ways and didn’t find any difference.

 

[stuartb]

So I've never been overly happy with my front brakes, for example I can if I try hard, pull the lever against my grip... in practice this hopefully would result in the ABS kicking in... but I feel I shouldn't be able to do this.

Walked by an RSV in Ducati a few weeks ago and tried the brake lever, it felt as it should...solid after a few Centimetres of travel....no chance of hitting the bar with it....also had a blast on an MT10 decatted and remapped, the front brakes were utterly superb..great feel and progressive... as a side issue it wheelied like **** lol.. amazing fun...

I don't remember my brakes being any different even when new...


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[alex]

Stu, my nissin mc would fail under hard use, lever moved way too far.

I think you should use a Brembo 19RCS if you're still unhappy

- Alex

 

[stuartb]

Alex I asked about that MC on here a while back to be told it might not improve the braking but was certainly better for adjustment/span etc..which did surprise me. I've never tried one so I wouldn't know

Confused.com

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[stuartb]

Anyone on here got one fitted, if so is there a marked improvement in overall performance

Some of the reservoir locations look a bit sus too, the Rizoma sits really high up in the cockpit..

I'll buy one if recommended...

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[fast_ryan]

Brembo RCS

I’ve used Brembo RCS master cylinders on other bikes and to be honest they were good but nothing particularly special. From experience the higher specification front master cylinders available from Brembo are significantly better but they are twice the price. Suffice to say I never bothered fitting an RCS to my previous Gen 3 as I never felt the need. That said I use Castrol SRF fluid and Brembo Z04 brake pads on track which are both absolutely superb.

 

[Carsonr6]

I’ve just fitted an RCS to the Gen 3 track bike. Not ridden it yet but the brake lever feels nice and firm at the minute.

I never bothered purging the ABS pump but I understand the theory behind the thoughts.


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[DrIoannis]

So I've never been overly happy with my front brakes, for example I can if I try hard, pull the lever against my grip... in practice this hopefully would result in the ABS kicking in... but I feel I shouldn't be able to do this.

Walked by an RSV in Ducati a few weeks ago and tried the brake lever, it felt as it should...solid after a few Centimetres of travel....no chance of hitting the bar with it....also had a blast on an MT10 decatted and remapped, the front brakes were utterly superb..great feel and progressive... as a side issue it wheelied like **** lol.. amazing fun...

I don't remember my brakes being any different even when new...


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This does not sound like S1000RR brakes. You had/have air in the system. When I install my M4 calipers and new front brake lines I tried to bleed the air out of the system. When I say I tried, I used 1lt of brake fluid. It did not work. It felt exactly as you describe it. I bought a GS 911 and finished the job in 1min. The brakes felt perfect. The S1000RR brakes are very very good. Go for a gs911 and you can also do more things on your bike.

 

[stuartb]

Cheers all, got me thinking !...

Rob might take a nip round to yours and get a look over that MC see how it feels if your OK with that, you can let me know mate.

Bikes due in to dealers next week to get that multiplug grafted into the loom, just noticed "service due " popped up on my dash yesterday, might get dealer to bleed.

Always liked the idea of a GS911 but resisted buying one as so far I've never needed...



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