Rear brake seized?

[special_k_828]

Hey FZ6ers,

I'm having a rear brake issue. While I was riding into work this morning, the back brake seized up on me. I was getting considerable drag. I turned around to head home. Bike was struggling to accelerate due to the increased drag from the back. All of the sudden, the back brake let go. I no longer had any pressure from the pedal though. By the time I got home, I pumped it a few times and pressure was restored, as was normal operation from the back brake. What happened? Piston seized?

I don't think any of the brake service (every 2 years) was performed on this 2007 I have. Thoughts? Give it a cleaning? Full rebuild all around?

Cheers,
K

 

[trepetti]

If there is any component that deserves to be over maintained, it is the brakes. I am betting that you had the piston seized in the caliper, but my guess don't count. It is your but on the line. Rebuild the caliper and flush with fresh fluid. You will sleep better. And do the fronts as well.

 

[greg]

it's pretty easy to take apart, i'd consider getting a new seal, giving the piston and seal seats a good clean (but don't scratch them), and refitting it with plenty of red rubber grease

I find a brass dremel took good for the seal seats, and metal polish + a cloth for the pistons works well. Wash any residue off with brake cleaner though.

 

[redballs]

Check your rear master cylinder, bolt is most likely overtightened. I had a similar experience when I let a unexperienced mechanic adjust my rearsets. The master cylinder would seize up and eventually become functional as the bike had time to sit.

 

[fastar1]

Seen this happen before with old brake fluid. Just change the fluid like was supposed to be done 4 years ago.

 

[Nelly]

This happened to me a couple of years back. I was losing power and having trouble to accelerate. I thought the rear brake had gone west on me.
In actual fact the rubber from the main stand had got caught in between the rotor and swing arm. It wasn't a brake issue at all.

Neil

 

[special_k_828]

I ordered the seals. I figured I might as well do it all....any of the things mentioned in this thread could be a factor. The fluid is definitely old and the calipers could use a cleaning.

Have others found the 2-year interval for changing the seals to hold true? I've just never heard of such a schedule on any other bike before. Seems excessive. Maybe a good cleaning and a fluid flush but a rebuild every two years?

 

[trepetti]

I ordered the seals. I figured I might as well do it all....any of the things mentioned in this thread could be a factor. The fluid is definitely old and the calipers could use a cleaning.

Have others found the 2-year interval for changing the seals to hold true? I've just never heard of such a schedule on any other bike before. Seems excessive. Maybe a good cleaning and a fluid flush but a rebuild every two years?

I bought an 05 last year and over the winter I ordered the seals but never did the rebuild. I let all my friends talk me out of it :spank:.

However each new season starts with a flush and bleed of the brake fluid. I will be rebuilding the calibers this winter for sure.

 

[TownsendsFJR1300]

The rear brake seals seems to last longer than the fronts. The two year replacement recommendation, IMHO, really isn't realistic.

I've found on my old FJR (same 4 piston calipers) and current FZ, I can get 4 maybe 5 years out of the front brake seals before the rubber seals just harden up over time, wear and tear, etc and need replacement (that's including yearly fluid changes).

To follow up on an above post, did you do any changes/adjustments to the rear brake adjustment shaft very recently? If the MC doesn't release the pressure fully, it'll eventually build up and apply the brakes as if you pushed the brake pedal...

**The dragging is one thing, the "sudden breaking loose" would concern me and I'd have to know what EXACTLY is going on inside that caliper (so it doesn't happen again).

BTW, being you have an 07 model, you have 4 piston front brake calipers. Even thou its not the current issue, keep an eye on the ft wheel "free spin". Once it gets below aprox 1/2 - 3/4 a rotation (ft end lifted, spin it by hand as hard as you can), your seals are sticking and will need attention. After rebuilding the fronts, I went form about 3/4 of ""free spin" to over 4 FULL SPINS.

 

[special_k_828]

The rear brake seals seems to last longer than the fronts. The two year replacement recommendation, IMHO, really isn't realistic.

I've found on my old FJR (same 4 piston calipers) and current FZ, I can get 4 maybe 5 years out of the front brake seals before the rubber seals just harden up over time, wear and tear, etc and need replacement (that's including yearly fluid changes).

To follow up on an above post, did you do any changes/adjustments to the rear brake adjustment shaft very recently? If the MC doesn't release the pressure fully, it'll eventually build up and apply the brakes as if you pushed the brake pedal...

**The dragging is one thing, the "sudden breaking loose" would concern me and I'd have to know what EXACTLY is going on inside that caliper (so it doesn't happen again).

BTW, being you have an 07 model, you have 4 piston front brake calipers. Even thou its not the current issue, keep an eye on the ft wheel "free spin". Once it gets below aprox 1/2 - 3/4 a rotation (ft end lifted, spin it by hand as hard as you can), your seals are sticking and will need attention. After rebuilding the fronts, I went form about 3/4 of ""free spin" to over 4 FULL SPINS.

Thanks for the information. I tested both wheels and have drag from both. When I spin them, I can hear a constant hiss/grind from the brakes. The front is giving me about 1/2 a turn...back is a bit worse. I will have to order the front seals as well.

What's the going rate on the front seals?

 

[TownsendsFJR1300]

Thanks for the information. I tested both wheels and have drag from both. When I spin them, I can hear a constant hiss/grind from the brakes. The front is giving me about 1/2 a turn...back is a bit worse. I will have to order the front seals as well.

What's the going rate on the front seals?

I paid $80 shipped to my door, 8-30-12 (for just the fronts, rear seal is original).

About a month ago, another member paid $100 to their door(US). Per that member, Yamaha changed the part #(which isn't unusual).

If you order thru Partzilla, I'd call them direct and tell them what you need. Yamaha has it somewhat confusing when you look at the parts fisch on what you need (see below link).

If you go thru a dealer, expect to pay well over $130.00 just for the fronts (that was for my FJR back in 2008-09 or so)

I got mine thru Partzilla before they changed their name:

Yamaha Motorcycle Parts 2007 FZ6 - FZS6W FRONT BRAKE CALIPER Diagram

 

[trepetti]

They are pricey unfortunately. You might want to look at Shs powersports. If you use the code freesept you get free shipping on orders over $50.00. I use them all the time and have never had a problem.

 

[greg]

i'd recommend going OEM, cheap Chinese seals might not fit correctly

 

[FinalImpact]

You never mentioned the condition of rotor or pads? Were the pads smoking, did the rotor turn blue or change color? Is the rotor still flat?

Also the rear is a floating caliper. That is, its a single sided piston so for the pads to wear evenly when that single piston extends to apply pressure, the caliper holding the adjacent pad must move inward (float) and center itself over the rotor. If its doesn't float in the slides it will bend the rotor and junk it.

When you go through the caliper, take the slide apart and clean it completely. Regrease and assemble.

The fronts rely on equal pressure being applied from all pistons to wear the pads evenly. The caliper is fixed in position and only the pistons move.

 

[special_k_828]

You never mentioned the condition of rotor or pads? Were the pads smoking, did the rotor turn blue or change color? Is the rotor still flat?

Also the rear is a floating caliper. That is, its a single sided piston so for the pads to wear evenly when that single piston extends to apply pressure, the caliper holding the adjacent pad must move inward (float) and center itself over the rotor. If its doesn't float in the slides it will bend the rotor and junk it.

When you go through the caliper, take the slide apart and clean it completely. Regrease and assemble.

The fronts rely on equal pressure being applied from all pistons to wear the pads evenly. The caliper is fixed in position and only the pistons move.

Ah, good to know. The rotors have not changed colour from what I can see. I don't know if it's warped though because I haven't gone for a ride since the brakes seized and released on me.

I don't know if the pads were smoking or not...I thought I smelled something burning though when this was happening. I will go for a ride tonight and assess the condition of the rear rotor, see if there is any pulsing, etc.

The front brake pads are nearing their limit...there looks be to quite a bit of meat left on the back.

I forgot to mention. There was a periodic clunking noise coming from the back brake prior to this failure. I should have given it my attention earlier.

 

[FinalImpact]

I would want to KNOW WHY THIS HAPPENED BEFORE RIDING AGAIN!

Thus, I would not ride as means of qualifying its acceptance! ** It was unacceptable as something was wrong! ** Find out what and WHY before riding or you may pay a bigger price! A dragging brake over some loose debris and BOOOOOM, your down! Not worth it IMO.

 

[TownsendsFJR1300]

Ah, good to know. The rotors have not changed colour from what I can see. I don't know if it's warped though because I haven't gone for a ride since the brakes seized and released on me.

I don't know if the pads were smoking or not...I thought I smelled something burning though when this was happening. I will go for a ride tonight and assess the condition of the rear rotor, see if there is any pulsing, etc.

The front brake pads are nearing their limit...there looks be to quite a bit of meat left on the back.

I forgot to mention. There was a periodic clunking noise coming from the back brake prior to this failure. I should have given it my attention earlier.

Also, when you check/service the two floating pins, make sure you use BRAKE SPECIFIC GREASE. Those pins/sliders do gum up with time, uneven rear brake pad wear is is a sure sign their hanging up as well..

You can likely just smell the pads once their out. If their not too bad, a quick scruffing on a nice flat sidewalk will remove any glazing. If the rotor is NOT warped, a light scuffing with sand paper wouldn't hurt either..

BTW, did you have the rear wheel off prior to this or have any work done to the bike recently?

 

[special_k_828]

Also, when you check/service the two floating pins, make sure you use BRAKE SPECIFIC GREASE. Those pins/sliders do gum up with time, uneven rear brake pad wear is is a sure sign their hanging up as well..

You can likely just smell the pads once their out. If their not too bad, a quick scruffing on a nice flat sidewalk will remove any glazing. If the rotor is NOT warped, a light scuffing with sand paper wouldn't hurt either..

BTW, did you have the rear wheel off prior to this or have any work done to the bike recently?

No. Bought the bike in the spring and rode it this season with it just the way it is. The bike was not very well maintained at all by the previous owner who had it for 2 years.

I'm usually a stickler on maintenance, especially for my bikes. I had a CBR600 F4 earlier in the season that I dumped a bunch of money into and sold before buying the FZ6. Buying this bike, I knew some things needed attention but wanted to leave everything to the off season to deal with. Winters are long here in Toronto.

The rear brake issue forces me to deal with it now. There is probably a month left of riding left.

Thanks for all the information. Your thread on the front seals will be useful when I do mine soon.

 

[deeptekkie]

I think your piston probably ****ed. (I've had cars to do this same thing) If it ever happens again apply the rear brake while carefully turning the wheel backwards. (This will usually un**** the piston and let it return to it's normal position. I got my car home this way) On a car it's got nothing to do with the fluid or hoses but everything to do with wear. (Many cars use plastic pistons but when you buy a replacement caliper it comes with a metal one)

 

[special_k_828]

Ok...my seals came in and I just finished installing them...new EBC Dot 4 in there as well. The rear brake continues to rub a little bit. I can hear it a bit when the bike is being walked. It's about the same as this guys:

[ame=http://www.youtube.com/watch?v=gjom8OxDHeM]Rear Brake Rub FZ6 - YouTube[/ame]

Is this ok? Is the piston supposed to retract all the way back? I can see some of the gold of the piston when the brake is not applied still.

Checked alignment...all the notches line up.