Question regarding front breaks...

[Mbarna]

... Is there a lead caliper? or do both calipers apply equally? My problem is that when i take my bike out for a ride, as i slowly stop and go, it appears as though one disc gets particularly warm, while the other stays cool... any particular reason why this happens or should i begin investigating?

also, can a caliper simply be cleaned and replaced if it is frozen (if this is the answer to my problem), or must i replace the caliper piston seals? (can't find em...)


thanks!

[Ken Talbot]

The caliper that is warming up could simply need a good cleaning. When you take it off, you will see how the caliper slides back and forth a bit on the caliper holder, and you'll probably see a lot dirt and grit. Clean it up with brake cleaner, and lube just those sliding areas (not the disc) with disc bake lubricant. This is a heavy silicone grease made for keeping the calipers slisding smoothly. Once you've done the one hat has been getting warm, it would be a good idea to clean the other one up too.

You should not have to remove the piston from the caliper for this job, unless there is a lot of cr@p under the rubber seal.

[Mbarna]

The rubber seals are gone and the caliper shows some rust. how much pressure should be required to move the caliper piston in and out of the assembly? should the piston rotate with the assistance of channel locks?

[Ken Talbot]

The piston should feel fairly tight in the caliper, but it should turn readily with a pair of channel-locks. It will feel hard to push back into the bore because there is only a small bleed-off orifice for the displaced brake fluid to pass through.

[COOL TOM]

Brakes

On the XJ the left front and the rear works off the rear brake lever. The right front works off the handle bar master cly. So if one side is getting warm you might be using one brake more than the other.

[CatatonicBug]

You should be able to securely stop the bike using ONLY the pedal (rear and left front calipers). Using the hand brake should also stop the bike, but not quite as securely. If that is not the case, then you should probably take a look at the brakes in more detail.

Remember, you should ALWAYS use BOTH the pedal AND the hand brake when stopping.