Rear brake on all the time.

[popa griffin]

When I try use my rear break it stays on. :angry:

I have a 2008 hyosung gt250r. :scooter:

Anyone know why it might be doing this and how can i fix it?



I tried to search the forum, but couldnt find any related topics specific to this. If there is any please supply link.

[JimO]

should still be under warranty?? take it back

[crazyhorse]

Why are you using the rear brake in the first place????

You should be using the front - I only use my rear when on shingle or if I need to brake in a hurry.

Take it back to the shop mate

[popa griffin]

should still be under warranty?? take it back

Tis out of warrenty by about 6months.

[JMemonic]

Heard of this before with these, isn't there some fault that causes this?

Someone will be on soon to say yes or no to that question.

If unsure of how to work on brakes get it to a shop, safer and simpler.

[popa griffin]

I know how to work on breaks. I just dont want to pull it all apart trying to find things, if someone might know whats wrong with it first. Would possibly save me a whole heap of trouble.

I cant be botherd doing it today as i been working all week and weekend. So ill probly start on it tomorow. But any info before hand would be nice. :yes:

[kewwig]

Check the adjustment of the pedal first to make sure the adjuster isn't holding it in the "on" position. If there's play in the pedal, it's likely to be a seized piston in the caliper (assuming rear disc brake). If you aren't confident with stripping the caliper - don't.

[riffer]

Jesus what a useless bunch of pricks you lot are.

Why bother posting in this forum if you don't know the answer? And as for not using half your brakes, give me a break... (pun intended).

Firstly, there's a few reasons the rear brake could be stuck. But the most likely one is that the pistons aren't retracting properly. It could be that you've got a fair bit of road gunk in there which has caused the pistons to get stuck on the outside.

You might actually use the rear a bit too. I use both brakes, especially trail braking when going into a corner to help tighten the line on the bike a bit.

Have a look at your brake pads. Can you see if they're worn or not? There should be at least a couple of mm pad on them - if less than that the pistons are probably sticking out so far they won't pop back in enough to stop working.

If the pads are okay but the caliper is filthy, take out the pads and give the whole shebang a good spray with CRC BrakeCleen. Then put the pads back in. If that doesn't work, try popping out the pistons and cleaning them - I'm not sure of the quality of the Hyosung brake pistons - it could be a bit of rust on the piston edges causing it to stick.

Have a good look at it then tell us what it looks like. Then we can help more.

[YellowDog]

When I try use my rear break it stays on. :angry:

I have a 2008 hyosung gt250r. :scooter:

Anyone know why it might be doing this and how can i fix it?



I tried to search the forum, but couldnt find any related topics specific to this. If there is any please supply link.
Come on mate, it's not rocket science. If the brake is engaging and not dissengaging; whatever is supposed to puch it backup isn't doing its job.

I am presuming that you are manually pulling the pedal back up to get it to go off?

If you've cleaned and lubed everything, you may need to look at whatever pishes it back up. It will be springs or little pistons. Are they connected and working. I suspect that cleaning will sort it all out.

If you follow it all the way through, you have a pedal at one end and a calliper pressing the pads on at the other. Just follow it from one end to the other.

AND always use your back brake, especially at low speeds; or you'll end up hitting the deck. And it does hurt.

[CookMySock]

One of our hyos did this. I pulled it all apart and tidied everything up. Washed it all out with brake fluid. Put some grease under the master cylinder boot to try keep the water out, and reassembled it with the same rubber, and it was mint.

If you are familiar with brakes at all, just whip the whole thing off as a unit and put it on the bench are rip into it. Theres no rocket science.

edit: IIRC the rubber boot just pulls off, and then theres a snap ring under that, and then it just all falls apart.

Steve

[kittytamer]

I had this exact problem. It turned out there was muck in the master cylinder that got into the small hole to the hose. It acted as a 1 way valve so the brake would go on but the fluid could not get back past the dirt so the brake stayed on. A good flush out with new fluid sorted it.
There is a clue in this picture that the rear brake wasn't behaving properly!

[Cheshire Cat]

Dust Anybody? no?
lol
dust seals??any other seals? ahh...its a hyobag? lol
take it to the shop?

Clean the brakes? brake fluid?

[WIO]

they must be really shitty bikes mine just locked on the rear brake, while taking it for a test ride after fixing another problem. Pulled mine apart and the master cylinder is full of rust, so it might be wise for hyobag owners to check theirs and prevent it from happening.

[CookMySock]

they must be really shitty bikes mine just locked on the rear brake, while taking it for a test ride after fixing another problem. Pulled mine apart and the master cylinder is full of rust, so it might be wise for hyobag owners to check theirs and prevent it from happening.Agreed. If you are happy with working on brakes, it's a simple fix.

Just pull the master cylinder off and strip and clean and lube it with brake fluid and reassemble with some grease under the boot. About an hours' work in total, if you take your time. No parts required - put all the old rubber back in, unless its really munted, but it wont be.

I've done two of these now. Don't be afraid of them - its all very simple.

edit: if you are not happy doing it yourself, then unbolt it and take it to any mechanic and get him to do it.

Steve

[p.dath]

edit: if you are not happy doing it yourself, then unbolt it and take it to any mechanic and get him to do it.

Wont that make it tricky stopping once you get to the mechanic? :laugh:

[CookMySock]

Wont that make it tricky stopping once you get to the mechanic? :laugh:Hehe nah just unbolt the master cylinder and put it in a plastic bag and go in another vehicle.

If you want to ride the bike with no rear brakes, remove the whole rear brake, caliper and all. Think ahead though - you will be surprised how much you rely on your rear brake.

Steve

[Ragingrob]

Hehe nah just unbolt the master cylinder and put it in a plastic bag and go in another vehicle.

If you want to ride the bike with no rear brakes, remove the whole rear brake, caliper and all. Think ahead though - you will be surprised how much you rely on your rear brake.

Steve

Really? I wouldn't think some people need to rely on their rear brake at all, some never use it!

Now riding a bike with no front brake, that's tricky, had to do it the other day haha bloody hard stopping on a downhill and needing to put left foot down with only the rear brake!

[izzyc]

Most people have got it right on here,about stripping the master cylinder and brake caliper, BUT dont just grease around the boots, put rubber grease [about $ 8 a tube] over the pistons,seals etc [internal on the caliper and master cylinder]..., ive done heaps of brakes in my time and yes they do need internal lubrcation.......

[CookMySock]

Most people have got it right on here,about stripping the master cylinder and brake caliper, BUT dont just grease around the boots, put rubber grease [about $ 8 a tube] over the pistons,seals etc [internal on the caliper and master cylinder]..., ive done heaps of brakes in my time and yes they do need internal lubrcation.......For real? I figured the grease would stuff up something in the hydraulics. Both these cylinders I did had perfect rubber in them - looked like they were perfectly well lubed. It was just the ferrous metal parts under the boot (outside the hydraulic internals) looked like it had never had any protection, so after cleaning it I filled it full of coppercoat.


Really? I wouldn't think some people need to rely on their rear brake at all, some never use it! It feels horrible braking the wet with only the front, but I'm referring more to little things, like slow speed stuff, and hill starts. It is usually taken as read the rear brake can be used, until suddenly it cannot. There is usually a confused moment, followed by an oh shit moment, followed by a crunch.

Steve

[mouldy]

Return hole in master cylinder will be blocked . remove and strip master cylinde and clean with brake clean and air or if needed a little piece of wire . rubber grease seals before reassembly

[Fub@r]

I have a similar problem at present with my Hyo.........except on all 3 calipers

After 25,000km my pads needed replacing. Went to mechanic got them all changed. 5,000km later they were grinding again. Go back to mechanic and the pad on the piston side of the caliper on all 3 calipers was completely gone.

So replaced the "destroyed" pads and off I went. So brakes sound as though they are sticking, all 3. Last night after 1,000km of this I pulled the front calipers off to check the brakes again. Pulled off the front left and noticed a bit of wear.

Now for the cracker..........pulled off the front right and there was no wear. Looking at the non-piston side pad I noticed a circular scratching on the back of the pad, then looked at the caliper and noticed about 1mm has been shaved off the caliper..........

When the caliper had been put back on the bike the pads the disk had gone up behind the pad and not in between the two pads. So for the last 1,000km one caliper has been braking using the caliper housing and the back of a brake pad!!!!!!!!!!!

To say the least I'm f'n furious right now.

[Hahn]

I have a similar problem at present with my Hyo.........except on all 3 calipers

After 25,000km my pads needed replacing. Went to mechanic got them all changed. 5,000km later they were grinding again. Go back to mechanic and the pad on the piston side of the caliper on all 3 calipers was completely gone.

So replaced the "destroyed" pads and off I went. So brakes sound as though they are sticking, all 3. Last night after 1,000km of this I pulled the front calipers off to check the brakes again. Pulled off the front left and noticed a bit of wear.

Now for the cracker..........pulled off the front right and there was no wear. Looking at the non-piston side pad I noticed a circular scratching on the back of the pad, then looked at the caliper and noticed about 1mm has been shaved off the caliper..........

When the caliper had been put back on the bike the pads the disk had gone up behind the pad and not in between the two pads. So for the last 1,000km one caliper has been braking using the caliper housing and the back of a brake pad!!!!!!!!!!!

To say the least I'm f'n furious right now.

That's fantastic!
What did your mechanic have to say for himself? Much damage to the disk/caliper?

[CookMySock]

When the caliper had been put back on the bike the pads the disk had gone up behind the pad and not in between the two pads. So for the last 1,000km one caliper has been braking using the caliper housing and the back of a brake pad!!!!!!!!!!Woops. Thats a bit embarrassing. I didn't think brakes could be assembled that "wrong".

... makes note to self. :banana:

Steve

[Fub@r]

Woops. Thats a bit embarrassing. I didn't think brakes could be assembled that "wrong".

... makes note to self. :banana:

Steve

I didn't think so either but tested it and it can easily be done.

Will post some photo's a bit later on for your enjoyment :)

[Fub@r]

Heres some pics:

[CookMySock]

LOL thats awesome.. :laugh:

Did a bike shop do that? It looks like you've been carrying your 200kg momma on it.

Oh well, its cheap enough to fix.. The hard part will be gettting the bolts out of the fucked discs.

Steve

[Fub@r]

LOL thats awesome.. :laugh:

Did a bike shop do that?

Yup was a bike shop

[Hadley]

I just took mine to the mechs, piston inside the master cylinder was poked, pitted and slightly corroded.
Had to order a new master cylinder from Richard Hyosong, will install when it arrives in a couple a days...