2009 Shimano XT disc brakes...
type_grim
Posts: 54
Good evening chaps,
Been a lurker on here for a while, and most of the time, i can find the answer to any question i have needed help on!
I own a 2007 Specialized Rockhopper disc, and in the last month, i upgraded to 2009 Shimano XT disc brakes... The Avid Juicy Three's were pretty poor.
I have cycled over 100 miles with the XT brakes, with no problems. They have seemed to bed in nicely and i am very pleased with their performance.
On Friday, i was out riding with a mate. We did about 40 miles across country, all hills/climbs, no jumps etc. It was raining all day and the bikes were caked in mud, beyond belief! The brakes sounded like they were covered in grit and mud.. that rubbing sound! Nevertheless, they were still operating fine.
Towards the end of the ride, my pal's brakes more or less stopped working. He could pull the levers back to the bars, and they wouldn't fully engage.
Mine however, were fine.,, Until this morning. I went out for a ride, on the road and did about 20 miles. The front brake was great (i run a 180mm rotor up front, and 160mm rear).
If i used the rear brake, i could pull the lever more or less back to the bar, and felt 'spongy' to the point, that it wouldn't even lock the back wheel up!
I took the rear wheel out, inspected the pads, wiped over the caliper/rotor with brake cleaner, and it is the same?
There is no wear on the pads, and i can't see any fluid leaking anywhere?
It's kind of annoying, as i have only cycled a few hundred miles on them, and the rear one is playing up?
My father suggested i may have boiled the fluid?
I am sorry to be so long winded, but any help would be mostly appreciated!
All the best,
Graham
Been a lurker on here for a while, and most of the time, i can find the answer to any question i have needed help on!
I own a 2007 Specialized Rockhopper disc, and in the last month, i upgraded to 2009 Shimano XT disc brakes... The Avid Juicy Three's were pretty poor.
I have cycled over 100 miles with the XT brakes, with no problems. They have seemed to bed in nicely and i am very pleased with their performance.
On Friday, i was out riding with a mate. We did about 40 miles across country, all hills/climbs, no jumps etc. It was raining all day and the bikes were caked in mud, beyond belief! The brakes sounded like they were covered in grit and mud.. that rubbing sound! Nevertheless, they were still operating fine.
Towards the end of the ride, my pal's brakes more or less stopped working. He could pull the levers back to the bars, and they wouldn't fully engage.
Mine however, were fine.,, Until this morning. I went out for a ride, on the road and did about 20 miles. The front brake was great (i run a 180mm rotor up front, and 160mm rear).
If i used the rear brake, i could pull the lever more or less back to the bar, and felt 'spongy' to the point, that it wouldn't even lock the back wheel up!
I took the rear wheel out, inspected the pads, wiped over the caliper/rotor with brake cleaner, and it is the same?
There is no wear on the pads, and i can't see any fluid leaking anywhere?
It's kind of annoying, as i have only cycled a few hundred miles on them, and the rear one is playing up?
My father suggested i may have boiled the fluid?
I am sorry to be so long winded, but any help would be mostly appreciated!
All the best,
Graham
0
Comments
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so to sum up.
rear brake lever is spongy?
pads are touching the rotor but the lever still moves?
yep?
air is the system or as Dad says boiled.
more reading here.
http://www.bikeradar.com/forum/viewtopic.php?t=12537260"Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
Parktools :?:SheldonBrown0 -
Thanks for that...I will order a bleed kit and give it the full monte!
Out of interest, how could air suddenly get into the system? And also, how would i have boiled the fluid?
I believe it has factory mineral oil, so is there anything out there i could use instead, to prevent this happening in the future?
Cheers,
G0 -
How hard to say without seeing the bike/you ride.
Mineral oil only i am afraid.
Please make sure that the caliper/pistons/rotor are all in the expected place and...are not just pushing each other about causing the lever to feel mushy."Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
Parktools :?:SheldonBrown0 -
I ride 40 miles during the week, and 40-50 of a weekend.
Week day riding is on road, and weekend, off road.
I think i have done, at most, 200 miles on these brakes...which were brand new when purchased.
Should they need to be bled this early on having covered not that much distance?
Or could there be a fault with the system?0 -
it depends on how you have used them not how far.
Like i said IF everything is in the right place at the rear they need a bled.
why no one on the net can say.
Like i said either air has got in or you have boiled them."Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
Parktools :?:SheldonBrown0
