Front break handle, how much movement

[rocks]

Hi Folks,
I took the bike offroad and took a tumble. The front brake banjo bolt was knocked and allowed the front brake to seep some brake fluid.

So today I topped up the front resevior, with fresh fluid, BUT..not sure I have put enough in or not or if there is still air trapped in the pipe somewhere.

There are no visible leaks anymore. And when i pull the lever in, it comes back toward the grip quite a way, but feels firm, though i seem to beable topull it a lot tighter in than i used too or so i think..

I havent had the bike out for a run yet. Probably going to try to put some more fluid into the resevior tomorrow as it was dark when i tried it today and so couldnt quite see the final level. My problem is I cannot remember how far I could pull the lever in, before the tumble..

 

[Colban]

ABS/non ABS?.
Have you knocked the brake lever span adjuster?.

 

[Psycho]

So today I topped up the front resevior, with fresh fluid, BUT..not sure I have put enough in or not or if there is still air trapped in the pipe somewhere. ..

1)To get any last bubbles out of the system , try tying back the brake lever over night then gently pump the lever the next day with the cover removed v slowly to get rid of the final bubbles which should have gone to the top of the system over night then top up, jobs a good in

or

2) take to BWM who have just charged me £78 on top of a service (how we love BWM) for a full fluid change must use liquid gold

 

[rocks]

Better..

I did the trick of tieing up the lever over night, during the week before i topped the resevior up. Topped it up on friday afternoon and still a bit spongy than I recalled. So topped it up again today to a higher level, and much better, but then hit a problem with oil light (seperate issue..lol.. dont you just love em..).

So bike is going in for a service next weekend, will get them to check it there. Costly yes, but I dont have the time to faff or experience to really know what i am doing with em and no time at present to learn. So hopefully problem solved..next weekend I hope!

 

[Steptoe]

. So topped it up again today to a higher level, and much better,

or experience to really know what i am doing with em and no time at present to learn. !

It makes no difference the the pressure by just "topping" up the reservoir, unless it was empty.

I think it's a wise decision to let someone else look at it

 

[rocks]

Cheers Niel..

Arh well goes to show how little I know of such things.. I thought the air gap due to lack of liquid in the reseviour would allow compression of the air, instead of fluid being driven, thus spongy feeling.

It feels more positive since topping it up, and i cannot locate any leakage, so if its not air in the reseviour, i take it must be air in the pipe??

(Its a non abs, standard 1150.. for the record)
Well its due in for a service, will ask them to kindly drain my wallet some more and look at it, just getting it over there is going to be fun.

PS Niel, sent PM about brake pads.

 

[zerocool]

I could be wrong but I believe when you apply the lever it isolates the resevoir from the brake line so that any air in the resevoir doesnt matter but im sure you are right that air would just compress if it were in there and the brakeline wasnt isolated.

Ive had a tank slapper or 2 in the time ive been riding and funny enough I foudn that after a particularily bad one my front brakes went terrible for the next few mile. I believe that the heavy shaking put air from the resevoir into my brake lines and then when I braked the air was compressing stopping the brakes from working properly.

Ive heard alot of people suggesting the "cable tie your brake lever" method for removing air but ive also heard that once thats done before releasing it you should go around the system tapping the lines and calipers to make any trapped formed air float to the top and be released into the resevoir when you take off the cable ties.

Would be interesting to hear if any of these myths are actually true!!! If in doubt though, take it to BMW, its brakes so they are kinda important to get right first time round!

the ZC

 

[flooky]

If you have a bad tank slapper the pistons are pushed back in by the pads,/discs..you should always test the brakes after a front end flap about.
(pump them back out)