Rear brake problems

Hello fellow Swingers

I have a 2007 silverwing 400 with 53.000kms on it.
The day after I bought the bike I went for a long ride and noticed a dragging sound from the rear, so I stopped and touched the rear disc and now I have no fingerprints(hot hot).
I told the mechanic to change everything and fix it for good, so he did: Rebuild the brake caliper, changed brake fluid, installed new oem parking caliber with new pads and new brake disc.

But I still think its grinding and the disc still gets insane hot.

When I press the brake caliper in towards the wheel with my hand, it seems to loosen up and the rear wheel starts running freely.

I would think he did everything correct and has greased what need to be greased, but it is if the caliber is not moving enough or something?

Do you guys experince hot rear brake disc and a low sliding sound from all the things spinning in the rear?

Sorry for spelling, english is not my main language

Hi Anders L.
I have had that problem on my bikes in the past.
Turned out to be to much fluid in the Master cylinder.
When the brakes got warm the fluid had no where to expand to so it gently put the brakes on further compounding the problem.
Rear is worse because it's heated front and back because of the "combined braking".
I now leave a gap of air at the top of the sight glass when checking fluids.

Hope this helps.

Be safe, be seen!

I have had a similar issue (that I caused)with my ST1300; in that instance the problem was caused by bad assembly in that I (somehow) cross-threaded the main caliper slide pin. This mean that the two pins that support the calliper were no longer parallel; as the pin was tightened it pulled the back pad onto the disc. My only solution was to replace the mounting plate that the calliper mounts to (with a used part).

One other test that you can do is when your brake is dragging on the disc, crack open the fluid bleed nipple slightly and see if that releases the drag. If so, you probably have an issue at the master cylinder that is preventing fluid pressure releasing when you let off the brake.

Hello
too much brake fluid or bad brake hoses
think that the brake pistons only move a few tenths of a millimeter when you brake and release

Hello,

What an absolute panel of good people and silverwing nerds! Love it, thank you so much.
Im gonna try to drain a little brake fluid later today and take it for a spin. Fingers crossed.

Hello Swingers
It didnt help with less brake fluid. Im dropping the bike off at the mechanic one of these days, he need to change my front tire anyway and he says he will look into it so that damn brake gets as its supposed to be. Its been an ongoing problem from 2020 and still very much is.
I can actually feel the bike is slower because of the dragging/grinding rear brake.
I really hope he can fix it this time!
Il let you know when theres any new

Hi Anders L.
Just an after thought, have you checked it's not the hand brake caliper binding on.
Put the bike on centre stand and un bolt the hand brake caliper and lift off the disc then see is the back wheel spins freely.
The hand brake worm screw can gunge up but gives no indication using the hand brake.

Hope this helps.

Be safe, be seen!

Sometimes the caliper pistons will stick in the bore or seals, if the surface of piston has dried up road grime or corrosion, pitting, etc., seen it many times, where pistons are pushed back in without inspecting/cleaning/polishing exposed area and brakes binding, the pistons will corrode outside of seal area and when you push the rough area into seal, it can cause a bind. Sorry for over explaining, had similar experience on the small piston for combined brake on front caliper, causing brake drag, new piston fixed it.

Hi guys, just an update.
Status is that the silverwing has got a new oem parking brake caliper with new pads, new rear disc, new pads front and back, new fluids and rebuilded caliper front and back. But it still drags. So now im waiting for a new oem brake distribution valve, and its not here before about 4 weeks. If that doesnt solve my problems im gonna get a nervous breakdown!!

Truly intriguing. I don't know of many faulty distribution valves with the SW but I stand to be corrected.

Setting the the parking brake is a fiddly business. When you 'tweek up' the locknut the wormgear tightens slightly. Try 'test-riding' with the parking brake pads set right back so that the parking brake lever has no effect. Don't forget to make the parking brake effective afterwards.

Apart from too much fluid in the reservoir, it's got me baffled.

The rear brake drags even without the parking brake caliper mounted

P-21179 wrote:

Hello
too much brake fluid or bad brake hoses
think that the brake pistons only move a few tenths of a millimeter when you brake and release

Did your mechanic check the brake lines and hoses for free flow both ways?  My old truck had similar issue, but it was dragging the front disk brakes on and off for several years, went thru several sets of rotors and brake pads, replaced both calipers, master cylinder, etc. one day my front right brake started smoking and literally locked up when I pulled over   . So, I took my brake parts (calipers, rotors, pads, etc.) to auto parts for warranty exchange. They gave me new parts, but recommended changing front brake lines and hoses, he said is not common, but the hoses sometimes swell and collapse internally, lines rust internally, etc., when fluid is not replaced regularly, blocking fluid return when brake is released. IAC (In Any Case), I did, problem fixed

Hey mr. ZRX (beautiful bike)
Yes he told me the lines are fine. But if the new valve doesnt solve the problem the brake lines is the only thing left to replace. But I sure hope the valve does the trick. When slowly applying pressure to the lever I can bottom it out. But fast pull operates like normal and doesnt even come close to the grip. So it could seem that the rings in the valve doesnt do there job good anymore. But new brake lines for sure, your right, they are from 2007 so could defently use knew, but I hope I can push that at least till next year.

Hi Anders L

You make no mention in your posts if you also had the Rear brake Master cylinder overhauled.

I'm gonna stick my neck out and say, if the answer is No, your problem will be bloated rubbers in the Master cylinder.

Hope this helps

Be safe, be seen.

Hey johny,
No im sorry I dont know why I didnt mention that, but yes that is done, it was rebuild last year with one of those rebuild kits.

I too have had the slow pull of the lever all the way back to the stop with no resistance, but a fast pull operates the brake normally.

I put a new piston kit in the rear reservoir and solved that particular issue.

Hi Anders, thanks for the update.

I have one more question about the Master cylinder.
Was the recon kit a Honda kit or aftermarket ?
I tried an aftermarket set first because of the cost of an original from Honda, but it made it worse so I shelled out for the Honda kit which cured it !
Seemed the aftermarket rubbers were a tad to big and not well formed.

Hope this helps.

Be safe, be seen.
Here's the genuine kits.

Hey Johny,
Im not actually sure, but just to be sure I just ordered a oem honda kit from cmsnl, just like on your picture, same part number. Gonna get that installed together with the new valve when the parts turn up.
I'l guess in about 4 weeks time or so I will be back with an update, hopefully that update includes a perfect functioning rear brake that doesnt drag!

So, sorry the long wait!
The silverwing hos gotten new brake dual valve thing, new brake fluids not topped all the way up to max, rebuild the rear brake master cylinder with oem parts, new brakepads and new rear brakedisc and new headbearing and tires. And damn it can stop now. Jesus. I dont think we proper realise how bad brakes we drive around with before they get rebuild. Damn it works. An also the caliper thread got drilled out and a helicoil was inserted instead, so the rear caliper could be proper torqued. And new bolts and groms and rubber boots and grease and all that for the rear caliper.
Now it doesnt drag anymore, but it still grinds just a bit. Im just gone drive it till it wears in, crooked or not, im not gonna bother anymore with that scooter.
Now I just need a new front tire again because its defect from factory, and thats the second tire they sent me. Jumps all over the road. Never bridgestone again for me.
So thats the update, sorry its a writing mess but im on road on the silverwing, just wanned to give a quick update

I'm glad it wasn't just me then! When I bought my 2001 SW the brakes 'worked'?. Rode through France to Belgium and back plus loads of local riding, with pillion!

When I decided to start checking out my SW properly, I was horrified at the state of both front and back brakes. Corroded pistons; sticky sliders, worn rubbers and dodgy pads. Discs also on the limit and gungy fluid.

Over time I replaced or repaired all the parts required and, like you, I realized how lousy my brakes had been. I watch them like a Hawk now and regularly take them off to keep them in peak proficiency. Also, I have a cleaned up rear caliper with stainless steel pistons in the garage, along with all the new seals, nipple, banjo bolt and washers. The existing caliper has stripped threads on the pad retainer pin which the helicoil didn't quite fix because of the blind stop. However, it's in, it's solid and is working for now.

I'll feel much happier when the replacement caliper is on the bike. For now, the brakes are the best they've ever been