Front brake issue

[vettrick]

I went for a nice Sunday afternoon ride on my '09 FZ6, 10K miles on the clock.
All was good. About 30 minutes into the ride I grab some front brake but the lever goes down right to the handle bar with no effect. I could pump it up but then it went right down again. I limped home with no front brake. I did feel some something in the front end like the brakes were dragging a bit or something like that.
Checked the pads and they still have some meat. Checked the level and it was high.
What gives? Is the master cylinder at the brake lever gone? Those things are expensive! Is this a common problem?

 

[FinalImpact]

Danger Will Robinson! That's scary! Glad your OK!

Any chance you put new levers on it? If there are no fluid leaks anywhere it has to do with adjustment.

If it lost fluid from either the calipers or the MC, you need parts. You could have ballooned a line, just haven't seen that happen yet.

Inspect MC

• Confirm no leaks out of boot.
• Confirm its full of fluid. If empty, the pads should be shot or you have a leak.
• Inspect lever - see if there is a gap for the plunger.
• If there is NO gap and NO free play for the plunger, adjust it, or free it up so the black rod with the ball has a small gap. REMOVE the lever for complete inspection!. Having free play allows the reservoir to fill the the piston area and move the caliper pistons. IF the LEVER is partially depressed, fluid is NOT getting into the piston and it may initially have brake but run out of lever travel before being effective.

I really want to know what changed over nite? Has anything been done to it? If not, your pre-ride inspection has let you down.

When is the last time the brakes were bled, fluid replaced?

If the line set balloons when pulling the lever, new lines are in order.
If the pads are worn to nothing, fluid level could be the gating factor that you simply wore it out without topping off the fluid.
If the pads are good but the fluid is low, that's neglect.
Confirm there are no leaks at the calipers.

After that, need more details about the conditions of all things. This could have ended very badly, Again, glad your safe! I'd likely be over cliff if mine failed.

 

[DeepBlueRider]

Check if your brakes are not dragging. From your description it sound like it's possible you've boiled brake fluid.

Other than than I would go through FinalImpact's list. If nothing would show up, I would suspect master cylinder to be due rebuild as you might have INTERNAL leak on master cylinder piston.

 

[Carlos840]

Could i be something simple, like the pistons not coming back freely and causing drag?

On my 2009 the pistons were so full of crap some of hem barely moved in or out anymore.
I took the calipers and pads of pumped the brakes a bit to release the pistons and get them out of the caliper enough to see the clean line (don't pump to much, you can push them in manually if one gets out to much) and then use soapy water and brake cleaner with a tooth brush till the pistons are clean.

Just doing that greatly decreased drag on my brakes


This is a video that's pretty good on the subject:

[ame=http://www.youtube.com/watch?v=FNz00OTRLzM]Delboy's Garage, Essential Winter brake caliper cleaning. - YouTube[/ame]


Not sure that's the problem but it can't hurt to try! Also as the other guys say, make sure your lines are ok, your master cylinder full and your lines bled!

 

[TownsendsFJR1300]

+1 on both posts above..

Also, Yamaha like the brake calipers rebuilt at 2 years.

I've found you can get 4-5 years before the caliper seals start hanging up causing excessive drag on the rotors. IF, they were dragging more than usual (even under normal riding) they'll heat up the calipers and brake fluid and as posted above, boil the fluid losing all the brakes.

With the bike cooled down now, do you have any brakes? If so, please put the bike on the centerstand, a sizzoe jack under the header to get the front wheel in the air. Give the front wheel a good hard spin by hand. You should get at least 3/4 a turn. If it stops immediatly, either the seals are hanging up or the MC is keeping pressure on the calipers(most likely the first).

To verify its the calipers, crack the bleeder screws loose, ANY RESIDUAL PRESSURE in the system will be RELEASED. If the brakes still drag bad, its caliper rebuild time. You'll also find if you place a thin, long screwdriver inbetween the brake pads and the rotor, one or more (you have 4 on each rotor) pistons, (two on each side) will be hanging up and be very hesitant to release.

 

[Carlos840]

+1 on both posts above..

Also, Yamaha like the brake calipers rebuilt at 2 years.

I've found you can get 4-5 years before the caliper seals start hanging up causing excessive drag on the rotors. IF, they were dragging more than usual (even under normal riding) they'll heat up the calipers and brake fluid and as posted above, boil the fluid losing all the brakes.

With the bike cooled down now, do you have any brakes? If so, please put the bike on the centerstand, a sizzoe jack under the header to get the front wheel in the air. Give the front wheel a good hard spin by hand. You should get at least 3/4 a turn. If it stops immediatly, either the seals are hanging up or the MC is keeping pressure on the calipers(most likely the first).

To verify its the calipers, crack the bleeder screws loose, ANY RESIDUAL PRESSURE in the system will be RELEASED. If the brakes still drag bad, its caliper rebuild time. You'll also find if you place a thin, long screwdriver inbetween the brake pads and the rotor, one or more (you have 4 on each rotor) pistons, (two on each side) will be hanging up and be very hesitant to release.

After the below pic is open, click again to enlarge it further..

How hard is it to change the seals? I have done quite a bit of work on cars and on my FZ6 but never something like caliper rebuild!
I mean, i did my own fork oil change and always do my services and things like pads, throttle body sync etc, do you think i will be able to do the seals, or does it take special tools and actual mechanical knowledge?

 

[TownsendsFJR1300]

How hard is it to change the seals? I have done quite a bit of work on cars and on my FZ6 but never something like caliper rebuild!
I mean, i did my own fork oil change and always do my services and things like pads, throttle body sync etc, do you think i will be able to do the seals, or does it take special tools and actual mechanical knowledge?

If you've done that and have an air compressor (even a small one) its not hard to do... You'll spend more time bleeding the dry brake system than swapping seals... The 04-06 have 2 sets of seals per caliper, the 07 and up, 4 seals per caliper. (the 2009 model, ((same as the 07 and 08 is shown below))

There's numerous threads on it. On my 07, before re-building the calipers, they spun maybe 1/2 turn. As of yesterday (doing some maintainance), I'm getting 2.5 full turns..

If you go for a ride, 40-50 MPH, stop with the REAR BRAKE ONLY, then feel the front rotors by hand. If their hot or very warm, their dragging too much and need attention. You can check the rear the same way but its rare (I still have the original rear seal in mine) for it to bind up like the fronts. I guess with the multiple pistons, there's not much movement and of course the fronts get hotter (harder on the rubber seals) and wear faster. The front seals tend to NOT retract, stay extended out, and thus drag with time/mileage..

 

[Carlos840]

If you've done that and have an air compressor (even a small one) its not hard to do... You'll spend more time bleeding the dry brake system than swapping seals... The 04-06 have 2 sets of seals per caliper, the 07 and up, 4 seals per caliper. (the 2009 model, ((same as the 07 and 08 is shown below))

There's numerous threads on it. On my 07, before re-building the calipers, they spun maybe 1/2 turn. As of yesterday (doing some maintainance), I'm getting 2.5 full turns..

If you go for a ride, 40-50 MPH, stop with the REAR BRAKE ONLY, then feel the front rotors by hand. If their hot or very warm, their dragging too much and need attention. You can check the rear the same way but its rare (I still have the original rear seal in mine) for it to bind up like the fronts. I guess with the multiple pistons, there's not much movement and of course the fronts get hotter (harder on the rubber seals) and wear faster. The front seals tend to NOT retract, stay extended out, and thus drag with time/mileage..

Good to know thanks!

I think they are ok for the moment, after cleaning them properly i get a bit more than a full turn... But since the bike is 4 years old i guess it will have to be done next year sometime!

 

[TownsendsFJR1300]

Good to know thanks!

I think they are ok for the moment, after cleaning them properly i get a bit more than a full turn... But since the bike is 4 years old i guess it will have to be done next year sometime!

If you got a full turn, I wouldn't mess with it (unless your bored, have $100 to spend and a couple of hours) :thumbup:

 

[Carlos840]

If you got a full turn, I wouldn't mess with it (unless your bored, have $100 to spend and a couple of hours) :thumbup:

Yeah, if it's not broken, don't fix it!

I will wait until i get in the 3/4 to 1/2 turn zone and then do it.

To the OP, before i did the clean like in the video i posted i had less than half a turn. After clean (took about 45 min) i get about a turn and a half, so it is really worth doing!

 

[vettrick]

Danger Will Robinson! That's scary! Glad your OK!

Any chance you put new levers on it? If there are no fluid leaks anywhere it has to do with adjustment.

If it lost fluid from either the calipers or the MC, you need parts. You could have ballooned a line, just haven't seen that happen yet.

Inspect MC

• Confirm no leaks out of boot.
• Confirm its full of fluid. If empty, the pads should be shot or you have a leak.
• Inspect lever - see if there is a gap for the plunger.
• If there is NO gap and NO free play for the plunger, adjust it, or free it up so the black rod with the ball has a small gap. REMOVE the lever for complete inspection!. Having free play allows the reservoir to fill the the piston area and move the caliper pistons. IF the LEVER is partially depressed, fluid is NOT getting into the piston and it may initially have brake but run out of lever travel before being effective.

I really want to know what changed over nite? Has anything been done to it? If not, your pre-ride inspection has let you down.

When is the last time the brakes were bled, fluid replaced?

If the line set balloons when pulling the lever, new lines are in order.
If the pads are worn to nothing, fluid level could be the gating factor that you simply wore it out without topping off the fluid.
If the pads are good but the fluid is low, that's neglect.
Confirm there are no leaks at the calipers.

After that, need more details about the conditions of all things. This could have ended very badly, Again, glad your safe! I'd likely be over cliff if mine failed.

No new lever, no leaks that I could see, nothing done to them. It just happened out of the blue.
I had never ridden without a front brake before.. You are right that it isn't comfortable at all! I headed straight home and went very slow.
Thanks all for the ideas. I will check the calipers and the rod free-play. Nothing has been done to them since new so they probably need some attention. I will let you all know what I find. It feels fine sitting in the garage but I don't dare take it out again until I figure it out.

 

[TownsendsFJR1300]

If their working correctly NOW (still check the other things), at the very least, do a brake fluid change / flush.