Just bought me a gs500 - front brake isn't very good

[zirconx]

Hello. I'm back after selling my old gs500e in 2004.  I just bought a 2005 gs500f tonight.  4600 miles.

One thing I noticed when driving it home is that the front brake doesn't stop the bike very well.  I'm gripping it pretty hard and its only slowing the bike down.  I also drove my friend's Ninja 500r tonight, and his front brake feels like it will lock up the front tire pretty easily.  It really stops the bike.  Shouldn't mine be like that?  What might be wrong?

I don't think there is air in the line because the lever feels very firm.  Its almost like its too firm, like the caliper doesn't want to move.  Any ideas?

Thanks!

[zirconx]

ok after reading through some of the old messages here, I decided to lube the pivot bolt.  That didn't seem to help, but as I was playing with it I think it might actually be spongy.  So maybe its just the old brake fluid.  I will change it and see if it helps.

[black and silver twin]

Bleed the brakes, the f model brakes are stupendous. if that doesn't fix it and your sure there's no old fluid/air in the system, then you may need a new brake line. if that's the case get a braided steel line. Also while your at it take the caliper off and inspect the pads if there worn replace them, if they appear to have grease on them replace them. then clean it all up with brake cleaner and a rag then lube the slide pins on the caliper. That should get the brakes up to snuff.

Ill bet its just air in the lines though.

good luck.

[Twism86]

Squeezing and it not stopping sounds like you need to bleed the brakes. New fluid and no air in the line should get them working. I would replace the pads for S&Gs too (unless they have been done recently).

[zirconx]

Only 4600 miles, should the pads even be close to replacement?  I could see there is some material left but I'm not sure how much is supposed to be there.

I hope bleeding helps, I will probably do it tonight and see.  Does the bike have a hydraulic clutch?  Any idea how much brake fluid I should buy for the front + rear brake and the clutch if needed?

[romulux]

Clutch is not hydraulic.

One bottle of fluid is more than enough to bleed both the front and rear.

[SAFE-T]

Brakes that had air in the lines would allow the lever to come back more than normal, and feel squishy.

Brakes that have stuck brake caliper pistons or some other mechanical problem like being designed by Harley Davidson  will be hard to squeeze, have little brake feel and even less effect on slowing the bike down.

[burning1]

It could be:

1. Stuck caliper piston (or two)
2. Oil on the pads
3. Glazed pads
4. Bad fluid.

The F series brake is plenty strong for the bike. I'd start by replacing the pads, and scrubbing the rotor. Follow up with fresh fluid. If that doesn't work, consider rebuilding the calliper.

[zirconx]

The lever feels spongy but it doesn't seem like its going back very far.

How hard is it to rebuild the caliper?  The bike only has 4600 miles I don't know why the caliper would need rebuilt already.  Maybe from not being used enough?  It is 6 years old.

Is there anything I could take apart on the caliper and clean easily?  A caliper rebuild doesn't sound like something I want to get into.

[burning1]

I wouldn't expect the caliper to go at 5600 miles. The one on my 93 still worked fine, after sitting for years.

The first thing I'd do is replace the pads. It's easy enough to ruin a pair.

If you decide to rebuild the calipers though, it's fairly trivial. Pop out the old pistons using brake pressure, air pressure, or a puller. Use a pick to remove the old seals. Clean thoroughly, and install fresh seals and fresh pistons. It costs about $30 for the rebuild kit. The hardest part of the job is getting the old pistons out. The most annoying part of the job is dealing with the brake fluid.

[zirconx]

Well I bled the brakes.  I think its a little better.  Its still not near as good as my friend's Ninja 500r I rode the other night.  But maybe this is as good as they get on a GS500.

[black and silver twin]

how does the lever feel?
it should build pressure quickly and become fairly stiff, should feel like squeezing a piece of wood almost.

How far does the lever move?
It shouldn't move much even with all your might.

if you pull the lever hard it should stop you like yesterday. the gs500f has the some of firmest brakes ive felt on a stock bike.

[zirconx]

how does the lever feel?
it should build pressure quickly and become fairly stiff, should feel like squeezing a piece of wood almost.

How far does the lever move?
It shouldn't move much even with all your might.

if you pull the lever hard it should stop you like yesterday. the gs500f has the some of firmest brakes ive felt on a stock bike.

Yes it becomes stiff very quickly, and doesn't travel very far.  I think it is stopping the bike much better now after I bled it.  Maybe the one on the Ninja 500r just takes less effort, so it feels like its easier to stop the bike with it.

[black and silver twin]

m/c-to-caliper piston-ratios could account for the difference in effort required, but the gsf brakes will park you now with a firm hand and good tires.

[zirconx]

m/c-to-caliper piston-ratios could account for the difference in effort required, but the gsf brakes will park you now with a firm hand and good tires.

Yes I think his lever travels a little farther so that makes sense that its the ratio.

[bombjack]

The GS500 brakes are strong enough to lock up your front wheel if you squeeze hard enough.
Don't ask how I know 

[bill14224]

Only 4600 miles, should the pads even be close to replacement?  I could see there is some material left but I'm not sure how much is supposed to be there.

I hope bleeding helps, I will probably do it tonight and see.  Does the bike have a hydraulic clutch?  Any idea how much brake fluid I should buy for the front + rear brake and the clutch if needed?

Perhaps the PO replaced the brake pads.  That would explain what's going on here.  Until the new pads wear into the grooves on the rotor it won't stop very well.  If I'm right in a few months it will be stopping great again.  And no, this bike's clutch is not hydraulic.

[zirconx]

BTW I used DOT3 fluid, will that be ok?  From everything I read DOT3 and DOT4 are compatible, its just that DOT4 has a higher boiling point.

[bidle]

I just recently bought a 2004 with 8,500 miles. I bled the brakes and looked at the pads to find they were a little thin, but not too bad. Lever was still too soft and it didn't stop the way I would like. A new set of standard EBC pads fixed the problem right away. No it stops on a dime, with great feel and feedback at the lever.

[marc]

My '91 is now breaking perfectly:
I replaced:
- Steel braided hose (it's a must, and its cheap, under $30)
- DOT5 liquid. Not expensive. ($9 a bottle)
- EBC doubleH pads. (it's a must for me: I'm used to brake with a single finger, find cheap at ebay.)
- After all these, I was not happy, and ended rebuilding the master cylinder and caliper (seals and dustseals) but what was causing trouble was a bent front axle!

Check all this.