Some help on brakes

[Irons]

Hoping someone can help here.

 

For context, I have a GT Zaskar Comp 2015, and I took in my rear wheel to LBS for a tubeless burp repair, and on fitting the wheel and heading out for a ride, I discovered I have almost no power in the rear brakes.

 

There is pressure on the lever, but it hardly applies any stopping power and creaks horribly under severe braking. While not sitting on the bike, it locks up perfectly. I've also had a look at the pads, and they seem to be sitting in the correct position.

 

Any guidance would be appreciated.

[Pulse]

My guess would be that something (brake fluid/oil) got spilled on either the disk or pads.

 

You can try to clean the disks with alcohol/spirits/something similar, but if the pads have absorbed an oily substance, its almost impossible to geat clean.

 

Perhaps do a searh on here or google for cleaning disks/pads

[igg]

+1 on contamination.

If you only took your rear wheel in, either they cleaned the hell out of the rotor and removed all the pad material, meaning you'll have to rebed your brakes or (more likely) grease or oil ended up on the rotor which has now transferred to the pad.

 

If this is the case, your best bet is to clean the rotor with isopropyl alcohol, and sand the top layer of the pads off, then bed them again. If the pads are too contaminated they'll have to be replaced.

[BaGearA]

IF resin pads throw them away and replace

 

IF metal pads soak them in acetone for a few hours then burm off excess and lightly sand with like 1000grit

[HowardSteele]

I'm reading you removed and took in only the wheel so the frame stayed at home?

if so no way they could dirty up your pads.Just let it stand for a day or so it might firm up if not just do a little bleed.

[Pulse]

I'm reading you removed and took in only the wheel so the frame stayed at home?

if so no way they could dirty up your pads.Just let it stand for a day or so it might firm up if not just do a little bleed.

OP indicates the brake is firm, so bleeding won't make a difference

[PeterF]

Probably got some oil or grease on the rotor which transferred to the brake pads. As BaGear said if they are metal pads you can soak in acetone, I have used meths, and then burn them clean.

[Irons]

Thanks for the response everyone - will get to that. When I refitted the wheel, the cassette was quite dry, so lubed the chain again, and in the process, the lid on the bottle broke and chain lube ended up all over the cassette and disc, so this could well be the cause.

 

Thanks again. Will revert once I've attempted a fix.

[Eugene Brown]

Thanks for the response everyone - will get to that. When I refitted the wheel, the cassette was quite dry, so lubed the chain again, and in the process, the lid on the bottle broke and chain lube ended up all over the cassette and disc, so this could well be the cause.

 

Thanks again. Will revert once I've attempted a fix.

Clean the disc 1000% with acetone, or a few times with degreaser and a good rinse, and then fit new pads. These after all are the bits that are going to stop you, so I wouldn't take a chance! For the price of pads, not worth it IMO

[porqui]

Thanks for the response everyone - will get to that. When I refitted the wheel, the cassette was quite dry, so lubed the chain again, and in the process, the lid on the bottle broke and chain lube ended up all over the cassette and disc, so this could well be the cause.

 

Thanks again. Will revert once I've attempted a fix.

 

You have your answer - clean.

If it is dry lube you might have to replace your pads.

[Mountain_Goat]

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