Help K9 Brakes

[Rafalynch]

Hello. I need some advice for my K9. One of the screws was rusty and I applied WD40 to several places, including near the rear brake caliper. Unfortunately, some WD40 fell into the brake disc and pads. To top it off, I couldn't think of anything else but to keep the motorcycle running and press the brakes to see if that would dry it out. Now when braking it gets stuck and takes a while to release the calipers... I've taken the motorcycle to the mechanic but it's still the same. When stopped, if you brake, it does recover and when you release the pedal, the wheel doesn't stay stuck... but when running, it does... How can I fix it? Thanks

 

[Snuffy]

Sounds like the wd-40 wasn’t the problem. It sounds like a sticky caliper. I would say a caliper rebuild is in order. Also check the pad as it may have uneven wear from the caliper sticking and it wasn’t noticeable until it got worse. Regardless I would suggest replacing the pads when you replace or rebuild the caliper. I would also recommend a different mechanic. IMO. Good luck

 

[Rafalynch]

Thank you for your reply and advice. I saw that they sell brake cleaning sprays and I thought that might solve the problem, although it is probably what I should have used when I realized that the brake disc had WD40 on it. Thank you.

 

[Sven]

Brake fluid is a basic routine flush-out every 2yrs. Probably was never done. Therefore, there is usually a goo that forms under the groove the quad seal seats in. The seal has memory and can retract the piston away from the pad. But this goo builds up under the seal and cannot go back to square. Thus the quad naming the seal.

Have to use a pick and brake clean to grind the goo out. That or dunk the caliper in vinegar for a day or two and then wipe the goo away with brake clean. Vinegar will expand rubber so no rubber when dipping.

Seal still looks fine and supple, I would reuse. Lawyerage print say replace with new... if you can find one.

 

[Rafalynch]

Thanks Sven. I'll tell my mechanic about it and see if he can fix it. Thanks

 

[Mikeinjersey]

Hello. I need some advice for my K9. One of the screws was rusty and I applied WD40 to several places, including near the rear brake caliper. Unfortunately, some WD40 fell into the brake disc and pads. To top it off, I couldn't think of anything else but to keep the motorcycle running and press the brakes to see if that would dry it out. Now when braking it gets stuck and takes a while to release the calipers... I've taken the motorcycle to the mechanic but it's still the same. When stopped, if you brake, it does recover and when you release the pedal, the wheel doesn't stay stuck... but when running, it does... How can I fix it? Thanks

Not sure which brake screws you were referring to but if the mechanic removed the mounting bolts he may have lost a shim or two and ended up cocking the caliper. Check to see your rotor is centered in the caliper.

 

[Jersey Big Mike]

Thank you for your reply and advice. I saw that they sell brake cleaning sprays and I thought that might solve the problem, although it is probably what I should have used when I realized that the brake disc had WD40 on it. Thank you.

rebuild the caliper and replace the pads. It's a pretty easy job to do. Make sure to use disc quiet when putting the new pads in..
Helps to have air compressor handy when rebuild to remove stuck pistons.

 

[Snuffy]

I realize you are in Spain which probably limits you greatly as far as competent mechanics with knowledge of big dogs but. You can do the caliper yourself as Mike said and save yourself some money. Learn a little and know it’s fixed right. If you have any problems or concerns you are at the right place for guidance. I go back to my original thoughts about the mechanic screwing it up to begin with or at the least not fixing it the first time around then why would you take it back? Good luck with it.

 

[SCC007]

Agree, just a simple rebuild of the caliper and pads and you will be right. If it has been a while or you don’t know when the last time it was done, recommend flushing all the fluid and maybe a master cylinder rebuild (gaskets), also not hard and can do it yourself just take your time and ask questions.

 

[Rafalynch]

Thank you very much for your helpful comments, I am in Spain and the most specialized mechanic for American motorcycles is two hours away. I don't dare to disassemble the brake calipers and I don't have the inch tool to do it either. I will wait to take the motorcycle to the mechanic and explain to him what you have told me here. Thank you and excuse my English.

 

[Mickmorris]

Thank you very much for your helpful comments, I am in Spain and the most specialized mechanic for American motorcycles is two hours away. I don't dare to disassemble the brake calipers and I don't have the inch tool to do it either. I will wait to take the motorcycle to the mechanic and explain to him what you have told me here. Thank you and excuse my English.

Make sure he uses DOT 5 brake fluid ONLY!! NO DOT 3 or 4!