[MBreinin]

My brake fluid was at the low line yesterday. So, I add enough to bring it up right beneath the full line. I rode the bike today for about 100 miles and I noticed about halfway through, when I stopped for gas, that the front caliper was dripping. Not a steady drip...but some brake fluid had definitely leaked out and puddled inside the caliper. Also did a nice job of spraying all over the outside edge of my tire.

I can't see where the leak is coming from. Any ideas? The front brake isn't soft, but I certainly want to find the source of the leak.

For the record, it never leaked until I filled up the reservoir.

Mike

 

[ceeco]

Well you got a few things to worry about here...surley your brake pads are now contaminated and in general I would not ride a bike with leaky front brakes till their fixed!

Suggest you clean every trace of brake fluid from the bike, use some rubbing alcohol and be sure to get the banjo fittings, bleed nipple, and brake line extremley clean. Take a strap/bungi of some type and wrap tightly around brake lever and handlebars to simulate a good braking effort. Sit back and watch for the fluid to leak...it should not matter if the bikes being ridden or not. If the caliper pistons are leaking that should be obvious too as it will leak from inside the caliper. Only thing that I can think of that would be intermitent would be a small cut in brake line that only leaks when hose/fork extends enough?? Bounce forks around if you see nothing when its still.

You will need new brake pads and the rotor should be cleaned very well with alcohol before final assembley.

Hope this helps...Good Luck!

 

[fredzeppelin]

you might not need new front brake pads.

don't know about the source of your leak... but i had my fork seals leak all over my front brake. definitely got oil all over the pads. tried brake cleaner. nothing. dealer had no sm pads in stock. then i got some emery cloth (from my plumbing kit) and hand sanded all four of the pads down until that dull looking color caused by the oil was gone. put em back together and it was better, but still not good. got on the road and dragged the front brake for 1/8 mile a couple times to get it real hot. then i did panic stops about as hard as i dared about 10 times. after that, all is right again. use at your own risk. your results may vary.

 

[MBreinin]

you might not need new front brake pads.

don't know about the source of your leak... but i had my fork seals leak all over my front brake. definitely got oil all over the pads. tried brake cleaner. nothing. dealer had no sm pads in stock. then i got some emery cloth (from my plumbing kit) and hand sanded all four of the pads down until that dull looking color caused by the oil was gone. put em back together and it was better, but still not good. got on the road and dragged the front brake for 1/8 mile a couple times to get it real hot. then i did panic stops about as hard as i dared about 10 times. after that, all is right again. use at your own risk. your results may vary.

I hear you. I need to find the source of the leak first and foremost. The bike continues to stop plenty hard. I am not a big brake user anyway. The motor provides so much compression braking that I only have to tap the brakes at most when riding and use them for final stop. However, I DO have to figure out what is up here. I had no leak or anything even remotely close until I added fluid to the reservoir. I haven't ridden it since I put it away yesterday though. I tried squeezing the brake hard and pushing down on the forks, but no leaking.

Mike

Mike

 

[ceeco]

Weird?? I guess you checked out the fork seals as suggested (good one FredZep).

Ok what about this...overfill brake resv. with fluid, ride bike brakes gets hot fluid expands, and the only/easiest place for fluid to release is the caliper piston seals. I have seen it happen on a bicycle hydro disc brake, but from atmospheric pressure while on a plane.

If you can't tell I enjoy the sport of trouble shooting:hmmm:

 

[MBreinin]

Weird?? I guess you checked out the fork seals as suggested (good one FredZep).

Ok what about this...overfill brake resv. with fluid, ride bike brakes gets hot fluid expands, and the only/easiest place for fluid to release is the caliper piston seals. I have seen it happen on a bicycle hydro disc brake, but from atmospheric pressure while on a plane.

If you can't tell I enjoy the sport of trouble shooting:hmmm:

I have not. I don't know how to, to be honest. The brake reservoir was at the low line. However, it never leaked or lost fluid. I filled it to just below the full line (with the cap on) with a synthetic DOT4 fluid. Then, I got a leak. It has to be something to do with the fluid level. I can't imagine I blew a fork seal, I wasn't jumping or anything like that. I may drain some brake fluid out and take it for a spirited ride and see what that does.

Mike

 

[ceeco]

Yeah, on the fork seals it would be pretty obvious. Look at the area where the two tubes slide together, if theres no sign of oil and the black seal is dry you should be fine. might as well take a look at the fork bottoms too make sure compression adjusters aren't leaking.

You could pull the caliper off and remove the brake pads for contamination inspection. Would allow you to inspect pistons as well, look for wet brake fluid, cracked pistons, etc..

I would not ride the bike till you figure it out, who knows when a car or worse a child runs out and you need every bit that Brembo can give. Theres no good enough when dealing with brakes.

I know you will fix it right in the end but careful on the test rides :thumbup:

 

[motorcycle2]

Just another thing to look out for... I have the exact same bike. One day I noticed fork oil all over the bottom of the fork leg that had dripped all over the brake rotor, tire, wheel etc. It was not the fork seals as I had just had them replaced for that ride. It was leaking where the fork tube threads into the lug. I pulled the forks and took them to ohlins. Upon dissasembly it stripped the threads at that connection due to the set screw design, but more importantly, the tube was never (from the factory) threaded all the way down into the lug. I could tell since the threads inside the lug were only halfway used, and the other half was still that gold color. It is important for the tube to be threaded all the way down since there is a rubber seal ring on the bottom of the tube that mates up in the bottom of the lug. Thanks a lot Marzocchi! :2hard

Anyhoo, I hope the same drunk on the assembly line didn't put both of our forks together. If that is your problem, let me know. I can help.