Weak Rear Brake

[hawncase]

My 2001 xr250r rear brake just seems weak.  I've changed out the caliper, brake line, master and resevoir to some effect.  I think my original caliper and master were shot, but the part out brake parts now have the rear brake working, but it just doesn't lock up the rear wheel the way I'd like them to. 

 

I had a 650L that had the same problem a few years ago.  It was common among the brp's.  Are xr250r's the same?

Edited November 2, 2013 by hawncase

[cpetz24]

I'm assuming you have bled the brakes.  With replacing all the parts that you have you could have introduced air in the system.  Air compresses, giving the brakes a weak, spongy feel, brake fluid doesn't. 

[Oil Baron]

Have you tried different pads?

 

I heard some aftermarket pads are more grabby and that stock pads are smoother.

 

I like smooth because I use my rear brake to go faster through turns.

 

For quick stops, use both brakes. 

[Zimman]

does it work better if you pump the rear brake ?

I know my XR 650 L does even after bleeding and new pads 

 

I have a master and caliper rebuild kit on the way from the TT store  since right after I do a bleed they work great  but back to weak in no time unless I pump it a few times 

 

and going down steep trails  I would like the rear brake to be 100%

Edited November 2, 2013 by Zimman

[Trailryder42]

What is the thickness of the rotor?

 

I once worn mine down below the minimum spec thickness and couldn't get the braking it should have had, even with new pads, until I replaced the rotor.

[campdirt]

check your rear brake pivot for wear.mine is so sloppy that it has added about 1/2" to my pedal travel.

[MadMat]

What is the thickness of the rotor?

 

I once worn mine down below the minimum spec thickness and couldn't get the braking it should have had, even with new pads, until I replaced the rotor.

 

+1

 

I had to replace the rotor to get the rear wheel to lock and lubricate the caliper pin because brakes were dragging and overheating.

[Fishin Scott]

Mine (90 model) was poopy and reluctant to lock wheel when really asked to ,

but a new set of pads made a huge difference in my case.

I was surprised because old pads have usually worked right up till

the death in the past

Cheers ?

[mudguy]

Mine (90 model) was poopy and reluctant to lock wheel when really asked to ,

but a new set of pads made a huge difference in my case.

I was surprised because old pads have usually worked right up till

the death in the past

Cheers ?

 

Usually the pads get glazed, pull them out and rub them aggresively in a figure eight pattern on concrete, it will deglaze them and they will work like new.

 

Then spray the pads and rotor with brake cleaner, and scrub the rotor with a scotch brite pad to clean any grease off.

 

I deglaze my pads every 4-5 rides especially the front, if you are tucking the front on downhill braking it is often because the pads are glazed and have to be pressed too hard against the rotor, and they will grab intermittently causing the front to lose traction and tuck.

 

If you have air in your brake lines the pads will glaze almost immediately, when the air heats up the pads don't retract from the wheels, rub, and get cooked, I completely locked up the front end on my CRF once when I didn't get all the air out of the lines, the pads heated up so much it boiled the fluid and the bike came to a stop nearly chucking me over the handlebars.