[nimster]

I've stored my bike in my condo for the winter and haven't started it up in a few months. I took the cover off today to look at the beauty and tested the front brake level. I can depress the lever all the way with no resistance as if there's no fluid in there (it bounces back as it should though). The front brake reservoir shows the same level as it was before. I pumped the brakes a few times but nothing changed.
I can only hope its because it has been parked for as long as it has but I can't imagine why it feels this way; but then the system is supposed to be airtight.

Does anyone have any tips?

 

[sro]

Try flushing your fluid.

 

[nimster]

I was gonna take it out and run it, see if the abs pump running would pressurize the system. But I'm guessing at that point I will have air in there too..
It'll have to wait till April to flush anything. I'll do it when I replace my oil before the season.

 

[nimster]

flushed the front. it was good for a day. and pretty much back to the same. there's no fluid anywhere around/on the bike. The reservoir level hasnt changed. Not sure what to try next

 

[netaron]

May be a leak, but also, your master cylinder may have gone the way of the dodo. If there's no fluid leaking anywhere, it seems like the MC isn't creating the necessary pressure to push fluid through the system. I have not taken an MC apart, so not certain what to look for. But if there's no pressure.....

 

[netaron]

One other item, it seems you have the hp4, I recently replaced my stock MC with a brembo RCS19, if you don't mind spending the dough, impo it is the best money spent on brakes as it has been suggested to me on this forum. The front brake no longer has the initial crazy bite, and is much closer to my other bike's feel, and the "feel" or initial bite is adjustable.

 

[sro]

I'm wondering if you have a warped rotor. This might be pushing a piston in.

 

[Bangkok_rider]

have you felt just under the master cylinder? If your seal is damaged you will get a tiny amount of fluid there and sometimes it doesn't drop on the bike.

I've also had a problem once with a reservoir tank that wasn't sealing right. The fluid would be fine immediately after I changed the fluid but then moisture would get in and within 2 or 3 days it was exactly as you described. (had the reservoir issue on my HP4)

 

[nimster]

I have the Rizoma front reservoir; used to have a bit of wet nipple situation under the reservoir but fixed that last year. No leaks anywhere i can see since then. i'll take the seat off and check the ABS pump seals where the brake line joins and check for leaks. I will flush the front again completely.

I wouldn't mind spending money, after all bikes are a money pit! lol but I would go for the billet MC rather than the RCS, heard better things about the billet vs RCS although I don't track the bike so I'm not sure if I wanna spend 2x as much as RCS MC. Thoughts?

@sro even if the rotor was warped I'd feel it when braking (pulsing brakes/ bike rattle/noise); that doesnt seem to be the case although I'll check it in the light tomorrow.

This is my front reservoir setup: https://www.s1000rrforum.com/forum/...818-mounting-rizoma-front-reservoir-help.html

Will update the thread with findings..

 

[aloosh]

i've had this happen before and ended up cleaning and flushing the entire brake system and the MC, turned out to be the aftermarket levers i had were not hitting the little pin thats inside the MC. Not sure if that helps

 

[netaron]

I have the Rizoma front reservoir; used to have a bit of wet nipple situation under the reservoir but fixed that last year. No leaks anywhere i can see since then. i'll take the seat off and check the ABS pump seals where the brake line joins and check for leaks. I will flush the front again completely.

I wouldn't mind spending money, after all bikes are a money pit! lol but I would go for the billet MC rather than the RCS, heard better things about the billet vs RCS although I don't track the bike so I'm not sure if I wanna spend 2x as much as RCS MC. Thoughts?

@sro even if the rotor was warped I'd feel it when braking (pulsing brakes/ bike rattle/noise); that doesnt seem to be the case although I'll check it in the light tomorrow.

This is my front reservoir setup: https://www.s1000rrforum.com/forum/...818-mounting-rizoma-front-reservoir-help.html

Will update the thread with findings..

The actual brand is probably irrelevant, as long as you know you can minimize the initial bite to your liking, it was just a model that worked for me, but I guess I should've been a bit more clear. Regardless, if you are planning on flushing the entire system, I'd suggest a GS911 to help flush out the abs pump.

 

[Bangkok_rider]

I have the Rizoma front reservoir;

Yep - that was what I had on mine causing the grief. My issue started about 30 days after installing the Rizoma reservoir. Went back to stock and no more issues.

 

[nimster]

But I've had the reservoir for like 3yrs and literally haven't touched it. I dont understand why would it cause issues and how, especially that i dont see any leaks.. puzzling

 

[wfo439]

But I've had the reservoir for like 3yrs and literally haven't touched it. I dont understand why would it cause issues and how, especially that i dont see any leaks.. puzzling

After 42 years of fixing all stuff mechanical and electrical, 30 years as a stationary engineer, (building trade) I've learned not everything has a plausible explanation. Or an explanation that makes sense to you. Sometimes after running out of ideas, you try something you don't think will work but it won't hurt and suddenly the problem is fixed. In those cases, I usually tell myself it's better to be lucky than good.

You have to start your trouble shooting process somewhere. Stock or Brembo res seems like your cheapest option. And based on what you have said the only non stock component. Only other options are MC, brake lines or calipers.

 

[nimster]

I totally understand what you're explaining. I've been in IT for some 20yrs and every once in a while we'd run into an issue that gets fixed by trying something unrelated!
I'll change back to the stock reservoir and give it a shot.

I might also add, the brake lines are spiegler, not stock. MC, calipers and pads are stock. 22000km and counting.

 

[DrIoannis]

Try to bleed the air out of the system with GS911/BMW tool. I think you have air in the system.

 

[nimster]

If I may admit, I've taken it to the BMW dealer for the bleeding. I have never been brave enough to try anything to do with brakes but I'm okay doing most other mods/maintenance on my own. Hopefully they do use their own version of GS911 to get it sorted. But it is also the second time the bike is going back so we'll see what they say.

 

[bennymx]

New master cylinder.

 

[nimster]

New master cylinder.

1- F**K
2- Okay, I can go for that
3- But why?
4- Which vendor can help?
5- Will I need to switch back to ugly reservoir?

 

[bennymx]

1- F**K
2- Okay, I can go for that
3- But why?
4- Which vendor can help?
5- Will I need to switch back to ugly reservoir?

1. lol
2. Good
3. They do fail. What year is your bike? Seals may have perished. There is also history of these bikes failing master cylinders. They can be bled back to life and sometimes last only a small while before they fail again.
4. Various vendors. Manny can get you a Brembo MC.
5. Hoses should fit different master cylinders if the barbs are the same size.