Rear brake seized?

[TownsendsFJR1300]

Yes, the piston will stick out as the pads wear and will be visable. It's NOT going to retract fully or you'd need a lever that moves 6".

The best way to see how much drag the rear brake has is to take the chain off the rear sprocket, (secure it to the swingarm, out of the way), then just spin it(after retightening everything back to normal, pumping up the brake).

A little to some drag is normal, again, if it stops in a half a turn, somethings wrong/binding/pressurizing, etc.

With the chain on, its really hard to tell how much the brakes are/are not dragging.

Also, if you go for a ride (approx 40-50 MPH) and stop with the FRONT BRAKES ONLY, then quickly feel the rear rotor. It should be cold or ambient temp. If its hot, the brakes are dragging excessively. *Same procedure can be used for checking the front rotors

Making sure the brake slider bolts are clean with fresh brake grease is really important as they allow the entire caliper to center itself (with one piston and two pads, it slides to center itself for even pad wear). Hopefully you used Brake specific grease (won't fling off, super high heat resistance, etc)


BTW, did you find anything unusual inside, sliders stuck, anything?

 

[special_k_828]

Yes, the piston will stick out as the pads wear and will be visable. It's NOT going to retract fully or you'd need a lever that moves 6".

The best way to see how much drag the rear brake has is to take the chain off the rear sprocket, (secure it to the swingarm, out of the way), then just spin it(after retightening everything back to normal, pumping up the brake).

A little to some drag is normal, again, if it stops in a half a turn, somethings wrong/binding/pressurizing, etc.

With the chain on, its really hard to tell how much the brakes are/are not dragging.

Also, if you go for a ride (approx 40-50 MPH) and stop with the FRONT BRAKES ONLY, then quickly feel the rear rotor. It should be cold or ambient temp. If its hot, the brakes are dragging excessively. *Same procedure can be used for checking the front rotors

Making sure the brake slider bolts are clean with freash brake grease is really important as they allow the entire caliper to center itself (with one piston and two pads, it slides to center itself for even pad wear). Hopefully you used Brake specific grease (won't fling off, super high heat resistance, etc)


BTW, did you find anything unusual inside, sliders stuck, anything?

I did the test. The rear rotor and caliper were just a tad warm. Not hot. I did not find anything unusual when I took everything apart. The seals shape were a bit mushroom like as opposed to the new ones which were flat. I assume this is just how they wore.

The back brake bites a heck of a lot better than before now too. I used brake specific grease on the brake pad pin and that piece that slides back and forth.

I just ordered the front seals. I take it getting the pistons out will be a bit more difficult.

When I had the piston out in the back, icleaned everything with brake cleaner. Was I not supposed to do that?

 

[TownsendsFJR1300]

I did the test. The rear rotor and caliper were just a tad warm. Not hot. I did not find anything unusual when I took everything apart. The seals shape were a bit mushroom like as opposed to the new ones which were flat. I assume this is just how they wore.

The back brake bites a heck of a lot better than before now too. I used brake specific grease on the brake pad pin and that piece that slides back and forth.

I just ordered the front seals. I take it getting the pistons out will be a bit more difficult.

When I had the piston out in the back, icleaned everything with brake cleaner. Was I not supposed to do that?

I've never heard of the seals mushroom when worn, weird and definitly not right. Brake cleaner is fine (preferred actually, just make sure its fully evaporated)


Read this thread re the fronts:

http://www.600riders.com/forum/gara...cleaning-brake-calipers-need-little-help.html

Being there's 4 pistons on each side, I've found it alot easier if you have an air compressor (even a small with a burst of 100 PSI) to blow the pistons out (once the calipers are off the bike). One member was able to do it without an air compressor, hydralic pressure but once one piston pops, the hydralic pressure is lost..

Same procedure as the rear..

 

[trepetti]

I have the seal kits for my front and rear calipers. Planning to do them over the winter. Question. Do the seals go in a certain way ( do they have a lip or are they symmetrical )? Also, the Yamaha parts come with red grease. It this for the seals?

 

[TownsendsFJR1300]

I have the seal kits for my front and rear calipers. Planning to do them over the winter. Question. Do the seals go in a certain way ( do they have a lip or are they symmetrical )? Also, the Yamaha parts come with red grease. It this for the seals?

There are two slightly different sized pistons (not hard to see).

The seals I removed from my 07 FZ6 and 04 FJR(same caliper) all had square edges. One member recently ordered seals and some of the seals had a very slight bevel on the inside. Yamaha does NOT address this. I suspect it may be to make installation of the piston slightly easier.

And yes, the grease is (can be used) for the rubber seals. Ironic, but Yamaha again (both the S1 and S2 PDF shop manuals) does NOT address applying brake grease to the seals. The manual does state to use brake fluid on the seals.

Should you use the grease, just put a very light coating on the seals ONCE THEIR INSTALLED. It does make installation of the pistons a bit easier. Apply grease lightly to the retainer pins.

Actually, once the pistons and pads are out fully, the new, rubber seals (much more flexible than the old, hardened up seals) are PULLING the pistons back in, the grease is NOT.

I have used and NOT used brake grease on the seals at different times. I've found that the grease tends to collect more crap on the pistons. I don't use the grease and strictly use brake fluid when re-assembling (per the manual).

 

[special_k_828]

I just used brake fluid as well. The seals I bought were symmetrical...maybe the previous seal had that bevel that I described as mushroom shaped? I dipped the seals in new fluid and just popped them in. They went in easy and like they were perfectly made for that spot.