There are a few things that will tell you that your front brake is stuck:
- Engine feels strong, but the bike is lacking pep
- After a short jaunt around the block, your front disc is burning hot
- The bike has been sitting for any prolonged period of time
To prove once and for all that your brake is stuck on, put the bike up on the center stand. Have a friend (or some other source of 200 lbs) sit on the passenger seat to get the front wheel off the ground. You should be able to easily spin the wheel by hand.
Whatcha gonna do about it?
This repair is much easier than you would think. Steps are as follows, pictures coming soon.
- Put the bike on the center stand.
- Take out the two bolts that attach the brake cylinder to its bracket.
- Slide off the brake cylinder.
- Push the pressure cylinder back into its housing
- Put everything back together
- Pump the system back up.
In theory, this isn’t necessary, but I would be afraid to work on the bike on the side stand.
There are four bolts here. Two hold the mounting bracket to the fork. Those aren’t the ones we’re looking at. The other two attach the cylinder itself to the mounting bracket.
This is probably the hardest part. The harder your brake is stuck on, the harder this is going to be to remove. Sometimes you can shake it loose. Trying to jostle it along the circumference is much more productive than perpendicular to the plane.
On my CX500, it came off in a couple seconds just jostling by hand. I did a CB450SC a couple months before and it required persuasion with a rubber mallet. Do not use a hard-faced hammer as you could mar the casing or worse, miss and mar the disc. Once you’ve got the cylinder out of the way, this is a good time to check out the brake pads.
The reason the brake is locked is that the pressure cylinder isn’t returning back into its housing when the brake lever is released. Generally, if you push it back once, it fixes the problem. If not, you’re looking at a brake cylinder rebuild which is beyond the scope of this document.
You can press the cylinder in with a C-clamp and some wood blocks or rags to avoid marring the surface or you can try neat leverage tricks using only a couple of wrenches.
That’s it really. The cylinder should go back on much easier than it came off now that you’ve pressed the cylinder back into its housing. Make sure the bolts go back in tight. This is your main brake, remember.
Moving the cylinder manually usually screws up the pressure in the system. Pump on the brake lever until it is once again firm and feels like a brake.