[GerryH]

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The rear master cylinder wouldn't release and the brakes locked up resulting in the rotor warping. I have since rebuilt the master cylinder and caliper, backed off the brake adjustment to little or no brake function. Now when the weather is hot out, 90 f today, the rear caliper tends to expand and lock up the rotor. This happened today with the bike just sitting in the sun. When I went to move it back into the garage after it was outside all day the rear brake was almost too tight to move the bike. I have a replacement rotor for this bike but until I solve this self expansion of the caliper I don't want to put it on and risk over heating it as well.
Does anyone have any suggestions?
Thanks
GerryH

 

[DaveO430]

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It is probably the return hole in the master cylinder plugged not letting the pressure off. You have to remove the plastic fitting on the MC and clean out the tiny hole that is in the bottom of a larger hole.

 

[GerryH]

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I will check on this in the morning, thank you very much.
GerryH

 

[oharaLTD]

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If the caliper and master cylinder have been rebuilt, the only likely culprit will be the hose. The inside fail and do not allow fluid to return to M/C. If you release the bleeder and the wheel frees up, the trouble is most likely the hose with the recent rebuild of the caliper and M/C.

 

[GregForesi]

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I get a lot of mileage out of this photo. The red arrow points to the return orifice from the caliper back to the reservoir (the "spooge" hole). It's only .015" in diameter and when it's clogged it causes the brakes to lock. A broken guitar string is the tool of choice to clean it out. It's really hard to see even with the master out of the bike.It's located at the bottom of a larger diameter blind hole. When the bike is sitting in the sun the brake fluid can heat up and expand. If itcan'tget back to the reservoirit can push the pistons out at thecaliper.

The interior of the brake line can be an issue buta clogged spooge hole is far and away themost common cause. The front master has a spooge hole also.

 

[bojong]

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Hi,

I'm new to GL 1800. I used to own a Street Glide-Harley Davidson 2008. I bought my GL1800 from my uncle, 2010 model with 1720 mile.

Question: when I hit the front break on a bumpy road, I hears a squeky sound (very little). is it normal? If not what could be problem.

thanks before for any replies.

 

[brianinmaine]

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bojong wrote:

Hi,

I'm new to GL 1800. I used to own a Street Glide-Harley Davidson 2008. I bought my GL1800 from my uncle, 2010 model with 1720 mile.

Question: when I hit the front break on a bumpy road, I hears a squeky sound (very little). is it normal? If not what could be problem.

thanks before for any replies.

I'm not familiar with your problem, but if you hit the button "new topic" instead of reply to this thread, more people will be able to help you.

Welcome to the forum, and good luck!

 

[sandcastcb750]

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Also, check the rear caliper seal and piston. Any corrosion will not allow the piston to go back into the caliper and release the rotor.

The piston should actually be sucked back into the caliper when you release the brake.If the brake still holds after you open the bleeder valve, the piston is stuck. Should be very easy to roll the bike around, and even spin the tire on the center stand.

Also, as you ride and the piston is constantly touching the rotor, it will heat, expand the rotor until it really does lock up.

Sure check the master cylinder release hole as others said. If no satisfaction there, remove the piston and clean the corrosion out.

Good luck