My front brake drags just slightly when I push the bike around.  I only know because I can hear it, and it doesn't impede the motion of the bike.  When I'm done riding however, the front rotor is very hot, too hot to touch.   The rear rotor is not even close to that hot.  Should I be concerned?  What can I do to address this if it's not normal?

The front rotor gets pretty hot just from normal use..... it's tough to say if yours is getting "too" hot. If possible, try taking a relaxed ride through the neighborhood with just using your back brake, and maybe see if the front rotor is still getting hot?

Oh yeah: how old is your brake fluid? I'm wondering if some moisture got in the fluid and is boiling it to the point it's putting pressure on your caliper pistons.

Take the caliper off and compress the piston. It shoud go in fairly easily. Carefully pump the master and extend the piston slightly past where it was stiing. Look at the sides of thje piston. If they are grungy, clean them and try compressing the piston again. If it compresses more easily then that is most likely your problem. I used scotch brite and some motor oil and cleaned mine, both front and rear , but I did have to replace the rear brake hose. My is a 1989 and all of the brake parts were original. Working fine so far.

regards
Mech

Brake line is a new stainless steel HEL, fluid is new when the line was put on last year and still looks clear through the looking glass. Caliper is a newish take off from an SV650 from eBay.  I will clean the pistons and flush the brake lines again and see if it helps.

Look into this soon !

If the front brake seizes while riding, it will be a wild ride.  I had a Honda that did that.  The piston started having surface rust and didn't release the way it should.  Yes, clean up the piston and your problem may be solved.

I had a 40 year old Yamaha TX-500, didn't get around to changing the break fluid after fight with every thing to get the motor to run, so after many months in the garage I forgot, took it out for a few test rides and I was stoked that it was running, suddenly I went from 40MPH to 5 in what felt like a second.

The TX had a smaller non vented rotor single piston caliper and 20+ year old fluid in there, a proper GS front break should be able to lift the rear tire in the air! I wouldn't chance it, remove the caliper clean it up, and change the fluid.

I'm assuming you've had the front wheel off the ground & checked everything for correct rotation & operation?

I had my front rotor turn blue twice on my 97 GS and completely fade out once on long fast downhill runs in the mountains when running EBC organic pads, went to HH pads after that.  I think most GS riders using mostly front brakes will find the front rotor considerably hotter than the rear after a ride.

If there is any crud built up on the caliper pistons they can get a little tighter with each application until they lock up, had that happen once early on with the 97 riding year around here in NE OH.  Since then for most of the 180k GS miles on both the 97 and 02 GSs I've popped the pistons out and thoroughly cleaned them each time I've changed pads.  Quick easy bleed if you fill the calipers as you assemble them.

Pads are supposed to drag lightly on the rotors to wipe them free of water in the rain so they function immediately.  You should be able to hang the front end and spin the wheel with your hand and have it go a turn or two if it's not too tight.  Facing forward with bike on center stand and my right knee against the left fork slider I reach over and grab the right fork slider with my right hand and lift front end and spin the wheel with my left hand to check.

Checked by putting the bike on the center stand, holding it up and spinning the wheel.  It spun 5 or 6 times before it stopped and there was a pretty consistent brake drag noise.  I'm thinking it's probably ok, but I'm going to go ahead and bleed the system because the feel of the brake has never been the greatest since I put on the new caliper and steel line.  I'll also clean the piston as best I can.

I bled the front brakes with the engine running to help get any bubbles of air out.  I also took the caliper, brake pads, and slider bracket off the bike and pushed the pistons (I have two pistons with the sv650 OEM caliper) out a little with the lever.  Then I cleaned a little gunk off the pistons with some brake cleaner and a scotchbrite pad (as much of the pistons as I could reach).  They both moved out with the lever and in with just my hand squeezing easy enough even before cleaning, so I think everything was ok before .  Anyway...I cleaned everything up and lubed the slider pins, faces of the pistons, and areas that contact the back of the pad with permatex synthetic caliper lube.  I also went ahead and bled the rear brake since I had brake fluid and once it's open you can't use it for long.  I cleaned the back of the rear pads and lubed them as well.

Went for a ride and everything worked great.  More power and feel from both brakes from what I could tell.  Running the engine while bleeding the brakes really helped get the air out better.  At the end of my ride I rode around the neighborhood and only used the rear brake.  When I got off, the front rotor was completely cool to the touch and the rear was hot.  I think what I was seeing before was completely normal!  Oh well, now my brakes are good to go for a while longer.  Probably only 40% left on my pads though.

Unless your over due for a carb sync, running the motor while bleeding your brakes should not do any thing on a gs, they are not vacuum operated brakes.

Glad it worked out for you! 


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Make sure you didn't over-fill the brake fluid. It'll expand when hot, which can cause the system to over-fill and put pressure on the brake pistons.

Some drag is normal. Your brakes will be hot after use, even when you get off the bike. As other posters have mentioned, try going for a short (slow) ride around the neighborhood using only the rear brake. If it's still hot, you have a problem.

Quote from: robfriedenberger on May 10, 2014, 05:58:53 PM
Unless your over due for a carb sync, running the motor while bleeding your brakes should not do any thing on a gs, they are not vacuum operated brakes.

Glad it worked out for you! 

Running the engine creates some added vibration that can help move stubborn air bubbles along. I'm sure this was why he used this approach.


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Quote from: jdoorn14 on May 10, 2014, 07:14:39 PM

Quote from: robfriedenberger on May 10, 2014, 05:58:53 PM
Unless your over due for a carb sync, running the motor while bleeding your brakes should not do any thing on a gs, they are not vacuum operated brakes.

Glad it worked out for you! 

Running the engine creates some added vibration that can help move stubborn air bubbles along. I'm sure this was why he used this approach.


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Correct!

Quote from: burning1 on May 10, 2014, 06:08:37 PM
Make sure you didn't over-fill the brake fluid. It'll expand when hot, which can cause the system to over-fill and put pressure on the brake pistons.

Some drag is normal. Your brakes will be hot after use, even when you get off the bike. As other posters have mentioned, try going for a short (slow) ride around the neighborhood using only the rear brake. If it's still hot, you have a problem.

Thanks for the warning.  I made sure not to overfill.

Had the same problem. Fix for me was to pop the pistons, clean them and replace the piston and dust seals. Brakes freed up after doing that.

If the pistons are really corroded, cut, scratched or pitted it's worth buying new ones; they're cheap as chips and you mitigate the risk of the pistons damaging the seal, potentially letting brake fluid leak out and onto your pads and disks, which wouldn't end well. If you do change the seals, make sure you get them the right way around!