Rear Brake spongy

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SoCalFJR1300

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Had a local shop recently change my rear tire, now my rear brake is real spongy.

could the shop have done anything to cause this or get air in the brake line??

All they did was change the rear tire but I did notice this guy likes to let the brake caliper hang loose while he changes the tires, I've heard this is bad for the lines??

 
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Spongy brakes usually indicate air in the line, which requires bleeding.

A visual check of the area should reveal any brake fluid leaks. It's nasty stuff, so you'll want to be thorough.

If you find a leak, inform the shop immediately, and request that it be fixed at their expense. Be extra careful riding the bike until you sort out the problem.

Sloppy procedure to suspend the caliper by the brake line, and definitely not recommended. Ask the mechanic to please not do that, or better yet, do the wheel removal yourself.

 
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+1. Are the brakes actually spongy (soft pedal) or just don't provide normal stopping power?

If soft, How about when standing still? Are they soft the first time you press the pedal but then firm the second time? If so, he may have tweaked the brake disc causing excess runout. The wobbling disc can push the pads back into the caliper when you rotate the wheel.

As for hanging the calipers from the hoses, The calipers on motorcycles are pretty small and light. Letting them hang is not likely to cause a problem unless the hose is getting ready to go anyway, and in that case I'd rather make it crack while changing a tire than when out in BFE.

 
If a damaged hose caused the air to get into the line, it would seem that a good stiff push on the brake pedal would reveal a fluid leak in a hurry. There's a great deal of pressure in there, as you can guess. I'd lean on a mechanic loosening the bleed valve to compress the pucks, thus causing an air in the line problemmo. Bleeding the brake will flush out the air. Pretty simple to do. At least that will eliminate one variable.

Gary

 
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I would make sure any spacers or washers are in the proper location.
Spacers should look like shown in these pics (but not necessarily as dirty):

(Click on image for larger view)



The ABS sensor screw isn't firmed down in the second picture, yours should be.

Also check the ABS sensor plate is oriented as shown, it could be misaligned - that won't give spongy symptoms, but if you found a bodge-it-and-scarper mechanic, who knows?

 
My recommendation, Pump it a whole bunch of times. This will pump the rear pads to full contact with the disk. If it does not 'firm up' the pedal then look at air in the line as the cause.

BTW, always pump up your brakes, 'cause not doing so means the fist squeeze will do nothing! This can be disconcerting at the very least.

 
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If they opened the bleed screw to back out the piston (which is just STUPID, by the way) then you need to find someone else to work on your brakes!

But if you have to bleed them, remember that linked front pair of pistons..........

 
Ok I pumped up the brake pedal and after ONE pump it's firm for ONE push....then it gets spongy again with long travel.

I'm assuming there's air in the line and/or the master cylinder is going bad but the bike only has 16,000 miles on it.....but it is a 2008.

 
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Ok I pumped up the brake pedal and after ONE pump it's firm for ONE push....then it gets spongy again with long travel.I'm assuming there's air in the line and/or the master cylinder is going bad but the bike only has 16,000 miles on it.....but it is a 2008.
Definitely air in there. Bleeding is needed.
If the fluid's over two years old, replace it. Goes for the front brake as well.

 
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Ok I pumped up the brake pedal and after ONE pump it's firm for ONE push....then it gets spongy again with long travel.I'm assuming there's air in the line and/or the master cylinder is going bad but the bike only has 16,000 miles on it.....but it is a 2008.
Definitely air in there. Bleeding is needed.
If the fluid's over two years old, replace it. Goes for the front brake as well.
And the clutch...

 
Just changed rubber front and rear. Left the calipers dangling (it ain't heavy, it's my caliper). Brakes are just like I left them, not spongy at all.

But, I pull wheels myself, and take new tires and wheels to the shop for mounting and balance. $43 bucks for both.

I concur, you have air in the line.

PS: important tip - don't pump up any of the brakes until ALL of them are back together. Linked brakes! Duh!
weirdsmiley.gif


PPS: to open closed calipers, GENTLY pry apart with a thin tool, until you can get a smooth wrench in there to open them up enough to fit the disk.

 
PPS: to open closed calipers, GENTLY pry apart with a thin tool, until you can get a smooth wrench in there to open them up enough to fit the disk.
Know what I found works the best? Wooden door jamb wedges, the ones you'd use to level/plumb the framework if you were installing a new lightweight door, like for a bathroom or bedroom. They're cheap at your local hardware/home improvement store and are just a little wider at the fat end than the rotors. Just push them through to separate the brake pads, doing both fronts rotors at the same time. Plus they're soft enough to not have to worry about chipping or marring the pad surface.

 
Know what I found works the best? Wooden door jamb wedges, the ones you'd use to level/plumb the framework if you were installing a new lightweight door, like for a bathroom or bedroom. They're cheap at your local hardware/home improvement store and are just a little wider at the fat end than the rotors. Just push them through to separate the brake pads, doing both fronts rotors at the same time. Plus they're soft enough to not have to worry about chipping or marring the pad surface.
Yup. Me n Gfran used this method coupla weeks ago.

 
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