S1 Calipers on a 2008 FZ6 S2 rotor?

[Marcin]

S2 calipers have different mounting points - I believe the distance between the bolts is 100mm while here it's around 80mm ( the numbers might be incorrect, but I am sure they differ quite a lot ). That's why you surely have got S1 front forks and calipers.

 

[tyler2011]

There are other sites that have parts schematics, but I linked to one below that shows an exploded view of the front caliper assembly for an 2005 S1 model. Parts 8 and 17 are the slide pins (greenish bolts). The should back out and have a threaded portion, then along smooth portion with areas slightly removed for grease. They have special caliper slide pin grease (many cars have slide pins as well), but with that being said I use a good wheel bearing grease. As previously mentioned, the caliper should slide independent of the mounting bracket in plane with the front axle.

Partzilla Front caliper schematic

 

[TownsendsFJR1300]

Photobucket pic's accidentally deleted...

 

[TownsendsFJR1300]

To add. forgetting about the drag, can you actually bolt up the brake calipers to the forks completly?

If so (it appear so), try pushing the pistons in slightly in each caliper. They should move in fairly easily. put the calipers back on (DON'T PUMP THE BRAKES UP) and check for spinning.

If it FREE SPINS easily, your caliper seals have failed and are not allowing the brake pistons to retract and release the brakes... Brake seal sticking (from old age use) is not un-common. Yamaha recommends brake seal replacement every TWO YEARS


Bottom line, it appears to me, you have S1(old style) brakes/forks on your S2 bike.

And unfortunatly, the brake calipers need rebuilding (not just cleaning, new seals).

It is possible the master cylinder (especially if those after market levers are chinese knock offs), some have had issues with the brake lever NOT releasing pressure.

Simply cracking the bleeder screw at the caliper, would release excess pressure and release the brakes.

If the seals/pistons are stuck/old, releasing the bleeder screw won't make a difference..

***Re-reading your first post, you had rust INSIDE THE CALIPER. That is not good, nor acceptable. You should replace the piston(s) (if you keep the current front end/brake set up). Just cleaning 6 year old seals, will help, but WILL NOT CUT IT. I've done it also, it helped some, but barely, and that was with spotless pistons, etc. You need new brake seals (their not terribly expensive)**

Also, pull the "flotaing bolts" out, clean spotless, if rusty, address it. Spend the couple of $'s for brake specific grease and lube those bolts, inside the caliper, inside those boots, it needs to slide very easily. The brake specific grease will hold up to much more heat than regular grease and WILL NOT fling off (causing other issues)

 

[tigrtraps]

Tons of useful info in here guys, I really appreciate all the help. As there is plenty to do for my bike I'm gonna try to narrow down my exact issues on the front wheel. Though Townsend I'm betting you are right about rebuilding/replacing the calipers.

The brakes can be fully bolted to the forks no problem. The front wheel is just locked at that point and will not spin whats-so-ever.

I didn't mention it before cause I knew it wasn't hurting anything, but when I took apart those calipers to clean them there was an empty spider nest hidden between the 2 pistons. It was an omen of the ****ty equipment! Ha.

To add. forgetting about the drag, can you actually bolt up the brake calipers to the forks completly?

***Re-reading your first post, you had rust INSIDE THE CALIPER. That is not good, nor acceptable. You should replace the piston(s) (if you keep the current front end/brake set up). Just cleaning 6 year old seals, will help, but WILL NOT CUT IT. I've done it also, it helped some, but barely, and that was with spotless pistons, etc. You need new brake seals (their not terribly expensive)**

Also, pull the "flotaing bolts" out, clean spotless, if rusty, address it. Spend the couple of $'s for brake specific grease and lube those bolts, inside the caliper, inside those boots, it needs to slide very easily. The brake specific grease will hold up to much more heat than regular grease and WILL NOT fling off (causing other issues)

 

[TownsendsFJR1300]

Tons of useful info in here guys, I really appreciate all the help. As there is plenty to do for my bike I'm gonna try to narrow down my exact issues on the front wheel. Though Townsend I'm betting you are right about rebuilding/replacing the calipers.

The brakes can be fully bolted to the forks no problem. The front wheel is just locked at that point and will not spin whats-so-ever.

I didn't mention it before cause I knew it wasn't hurting anything, but when I took apart those calipers to clean them there was an empty spider nest hidden between the 2 pistons. It was an omen of the ****ty equipment! Ha.

Just to confirm, with the pistons retracted (and pads), you CAN BOLT ON the calipers and spin the wheel easily? Nothing dragging at that point?

 

[tigrtraps]

Just to confirm, with the pistons retracted (and pads), you CAN BOLT ON the calipers and spin the wheel easily? Nothing dragging at that point?

Fully retracted and I haven't pumped the brake lever yet? Haven't tried specifically that yet. At the last time I had my hands on it, once the calipers are on and the bolts are loosely on (hand loose) there was drag to where the wheel could only do a 1/2 spin. If I tighten those bolts to spec, which I've been using 29ft lb and have also tried looser and looser settings, the front wheel is locked. I think that makes sense? I'm new to all the wrenching part of bikes so I may certainly be explaining wrong.


First on my testing list is take off the calipers and see if the wheel freely spins. Next is making sure the pistons are pushed in and to mount the calipers BEFORE priming the brake handle for wheel spin, then prime the brake handle and check wheel spin.

That should help me narrow down the exact cause of the wheel lock. Well at least narrow down where I need to focus my effort. I'll grab more pics as well since I'm making you guys take shots in the dark.

 

[FinalImpact]

Pull the pads out, mount the caliper and then take note regarding the opening in the floating section of the caliper.
- When bolted down, the floating section that holds the pads should move freely in and out.
- It should NOT contact the rotor when centered.
- You should be able to center it over the rotor (it moves based on pad thickness), but it should easily slide.
- If they slide and the pistons can be depressed, and the caliper hangers do not contact the rotors, it points to a hydraulic issue like the MC return port being block. However, that doesnt explain why it spins when the bolts are loose.
- i would advise you bleed the brakes also. With the caliper bleeders open, you can/should be able too collapse the pistons easily and insert the pads. If you open the bleeders, do move forward and bleed them w/New DOT 4 fluid.
Also, please don't get discouraged here we all just want you safe. That said, you need the proper fender/improved hardware so that fender doesnt jump into the tire and ruin more than the bike. Thats safety issue.

Good luck!
Ps R6 forks are very nice!

 

[TownsendsFJR1300]

Fully retracted and I haven't pumped the brake lever yet? Haven't tried specifically that yet.

First on my testing list is take off the calipers and see if the wheel freely spins. Next is making sure the pistons are pushed in and to mount the calipers BEFORE priming the brake handle for wheel spin, then prime the brake handle and check wheel spin.

That should help me narrow down the exact cause of the wheel lock. Well at least narrow down where I need to focus my effort. I'll grab more pics as well since I'm making you guys take shots in the dark.

Exactly!

We're trying to narrow down that there's nothing physically jambing up between the dics/fork/caliper.

DO NOT PUMP up the brakes at this time..(as I suspect thats whats causing the dragging). If all assembled, STILL NOT PUMPED, and it rotates fine, thats good.

Once thats cleared and we know its ok, the issue is likely in the calipers (needing rebuilds) sticking (not unusual at all). That is the most common cause. NOW you can pump the brakes and check drag. With the rust you had on ths piston(s) and the OLD seals, their VERY likely NOT releasing, causing the drag

There's some other things it could be, (cheap chinese levers not releasing the pressure, the master cylinder-pretty rare) but PLEASE, do the other checks first. (One step at a time)

And +1 on removing that fender, thats an accident waiting to happen..

Please post what you come up with..

 

[tigrtraps]

I'm back helpful people on the internet! Finally got me some money back thanks to American Express. Keeping that card foooorever now.

Parts are on order, and I'll likely have a new thread as I'm replacing the forks with R6S forks, and jumping up to the 07-09 calipers.

Why replace the forks? Yea I don't think I mentioned before, at my 200lbs (with gear) those forks don't move an inch if you sit on the bike and try to bounce them. Solid as rocks. It also looks like a fun project to do and will let me replace the front fender as well.

Since I never came back after some troubleshooting, though it's moot now, I took the calipers completely off and spun the wheel to see if the bearings/axle were still good. Wheel spun a minimum of 5 revolutions every time I gave it a push. So that's at least good. Tried more fiddling with those old calipers and I think it just comes down to they are dead. The pistons don't release correctly, they can't be bolted on right. I'm still lucky I didn't ride for any real amount of time on them!

After I fix it up the real problem will be deciding to sell it, or make it a track bike.