85 fj1100 caliper issue

[bruce j]

1 have an 85 fj1100,it is all stock,the problem I am having is the front calipers drag on the rotors,you can barely push the bike,i rebuilt the calipers with seals and pistons from randy,same problem,didnt fix anything,any ideas??

[T Legg]

   If the rotor is warped bad enough it might cause that but it would be loose in one position.

[Tuned forks]

Another issue I've been warned about regarding autos is an internally collapsed brake hose.  They act like one way check valves.  Pressure goes to the caliper but can't be relieved when releasing the brake lever.  Try loosening the caliper bleeder screw.  If brake fluid squirts out and the wheel then spins easily then you have a brake pressure issue.  Maybe the brake lever is also not adjusted correctly?  If Pat sees this he's gonna tell you to replace those original brake hoses, provided they are old.

Joe

[Troyskie]

Has the master been serviced too?

As Joe said, change the lines if they're original.

[Pat Conlon]

The problem resides in the master cylinder....there is a relief port that is plugged.
Pull out the splash plate at the bottom of the reservoir, disassemble the seals and clean.

Also......Replace those 33 year old rubber brake lines!

[oldktmdude]

    What Pat said. The small return hole in the master cylinder corrodes and block the returning fluid.

[bruce j]

thanks guys,the brake hoses were replaced with braided ones from randy a few years ago,i am going to get a master cylinder rebuild kit from randy,thats great info about the relief valve,thanks again for the great advice

[red]

1 have an 85 fj1100,it is all stock,the problem I am having is the front calipers drag on the rotors,you can barely push the bike,i rebuilt the calipers with seals and pistons from randy,same problem,didnt fix anything,any ideas??

Bruce J,

In case the problem is not in the master cylinder, then it sounds like the calipers are not aligned with the rotors.  This problem is usually an easy nuts-and-bolts fix.

1. Loosen every fastener that holds the calipers, and the caliper mounting plates.  Work the calipers around, from side to side, to find where they want to be.  Use a heavy bungee cord for this next part.  Hook the bungee cord from the front brake lever, and go around the handgrip and the lever for as many turns as you have bungee cord, then hook the bungee end back to the the front brake lever.  The front brakes will be on, hard.  Tighten every fastener "snug" for the brake caliper mounting plates and the calipers.  Then on the next pass, make each of these bolts a little tighter.  Repeat this tightening sequence, until you get them all tight to the normal factory torque specs.  Release the bungee cord, and check the brakes.  They should be free-wheeling now.  

2. If not, loosen every fastener that holds the front fork tubes.  Hold the front wheel from steering to either side, and crank the handlebars for left and right turns.  By feel, find the place where the handlebars want to be, lined up with the straight front wheel.  Tighten all of the fork fasteners "snug", then working up to factory torque specs as before.  Then repeat the entire first procedure.

If these steps do not fix the problem, then you may have a front wheel with missing or misplaced spacers on the front axle.  Check the parts diagrams to be sure that all the right spacers are installed on that front axle, in all the right places, with the correct side of each spacer facing out from the wheel.  If you find anything installed wrong on the axle, get it set right, then repeat steps 1 & 2.

Do not assume that everything is fine, if it seems like the problem is fixed.  Test-ride the bike around a few blocks, then a few more blocks, without using the front brakes at all.  Check that the front disk rotors are not getting hot.  Warm is okay, but not blistering hot.  For the next few days, check the disk rotors for temperature after any short ride, when you have not touched the front brake lever on that ride.  If you have not applied the front brakes, hot rotors are a very serious problem.  There should always be some free play in the front brake lever.  If you ever put slight pressure on the brake lever, and there is NO free play (rock-hard lever), your disk rotors will be too hot to touch; STOP the bike immediately, instantly, and safely, before the brakes lock up, and let things cool off.  Do not ride the bike, if the brake rotors get hot like that.  Excessive heat at the brakes can and will lock the wheel, while riding.  The same applies to the rear brake, of course.

If you can ride the bike without using the front brakes, and the rotors stay cool (or just warm), then you should be okay there.  If you ever touch the front brake lever and there is no free play in the lever, stop the bike immediately.  Check for hot brake rotors.

Just FYI, old brake fluid can absorb moisture, and riding hard can boil that water in the brake fluid, causing hot rotors, and maybe a disaster.  Flush and bleed away all of the old the brake fluid on a regular basis, and any time you ever notice a brake lever with no free play after a hard ride.  Speedbleeders will make this job easy.

Keep us posted.

[bruce j]

thank you red ,for that information,i will check all that,thanks again

[bruce j]

I had some success ,the master cylinder was plugged up,and I tightened the caliper where it wanted to be,thanks a million guys