Brake pedal stiff

[mralex714]

My brake pedal has been stiff since I bought the bike ,along with poor braking. When I apply the brake pedal there is very little braking until I press very hard and it feels like all the braking is from the front brake.. I have bled the brakes several times, it feels better but not as good as my 89. Any thoughts?

[MiCarl]

Stiff probably isn't because they need to be bled.

 

Check the rear caliper. Look for the backing plates on the pads to have worn a slot on the front side of the caliper. If they're hanging up there it'll greatly reduce rear braking force.

[Marcarl]

Sounds like the brake system needs a complete tear-down and check over. I wouldn't want to trust my life on a brake system that shows problems. An 86 with never any service brings lots of problems to the table. Stainless lines would really improve the performance of the whole system as well.

[turtle]

Had same problem on mine the pivot point on rear pedal needed to be greased didn't find problem till it started sticking and dragging

[Ozlander]

Here's how I fixed mine.

 

http://i24.photobucket.com/albums/c33/Ozlander/BrakePedalzerk.jpg

[Prairiehammer]

Duane,

When you describe the pedal as "stiff", are you describing the action of the pedal? Does the pedal return easily after it is depressed? If not, a cleaning and lube is in order. Then clean and lube and adjust as needed the other pivot points in the rear brake linkage.

 

If your description of stiff has more to do with the feel of the braking when depressing the pedal forcibly, what some have described as a "wooden" brake pedal, you will have to investigate all the components of the hydraulic system to determine if there may be a blockage somewhere. If there is a blockage in the hydraulics, the pedal may feel 'hard' and the rear brake may seem ineffective.

 

Perhaps the rear brake caliper is not receiving the hydraulic pressure generated when the brake pedal is depressed.

 

Try to confirm that the proportioning valve attached to the rear master cylinder is clean, full of fluid (no air) and is allowing fluid flow to the rear caliper.

 

To check for this: loosen the rear caliper bleeder while depressing the brake pedal; as soon as you crack the bleeder, fluid should emit and the pedal should begin sinking. If you find that this does not occur, then move to the next point. The next point is the banjo bolt fitting on the rear caliper. Test as before. If there is noticeable fluid emission and the pedal sinks, then the problem probably lies in the caliper. If there is no fluid emission when the banjo bolt is cracked and the pedal depressed, you must move to the next joint; the banjo bolt connection on the proportioning valve where the hose to the rear caliper attaches. Repeat the test as before. If, fluid emits now, then the problem lies in the rear brake hose; some have found deteriorated inner lining of the brake hose has blocked fluid flow.

 

If at any of the mentioned connections you fail to get fluid when the pedal is depressed, the proportioning valve is faulty, dirty or blocked. It is possible that the proportioning valve has been disassembled by others and was re-assembled incorrectly. The proportioning valve can also appear to be perfect internally and yet not perform as intended, DAHIK.

[mralex714]

Duane,

When you describe the pedal as "stiff", are you describing the action of the pedal? Does the pedal return easily after it is depressed? If not, a cleaning and lube is in order. Then clean and lube and adjust as needed the other pivot points in the rear brake linkage.

 

If your description of stiff has more to do with the feel of the braking when depressing the pedal forcibly, what some have described as a "wooden" brake pedal, you will have to investigate all the components of the hydraulic system to determine if there may be a blockage somewhere. If there is a blockage in the hydraulics, the pedal may feel 'hard' and the rear brake may seem ineffective.

 

Perhaps the rear brake caliper is not receiving the hydraulic pressure generated when the brake pedal is depressed.

 

Try to confirm that the proportioning valve attached to the rear master cylinder is clean, full of fluid (no air) and is allowing fluid flow to the rear caliper.

 

To check for this: loosen the rear caliper bleeder while depressing the brake pedal; as soon as you crack the bleeder, fluid should emit and the pedal should begin sinking. If you find that this does not occur, then move to the next point. The next point is the banjo bolt fitting on the rear caliper. Test as before. If there is noticeable fluid emission and the pedal sinks, then the problem probably lies in the caliper. If there is no fluid emission when the banjo bolt is cracked and the pedal depressed, you must move to the next joint; the banjo bolt connection on the proportioning valve where the hose to the rear caliper attaches. Repeat the test as before. If, fluid emits now, then the problem lies in the rear brake hose; some have found deteriorated inner lining of the brake hose has blocked fluid flow.

 

If at any of the mentioned connections you fail to get fluid when the pedal is depressed, the proportioning valve is faulty, dirty or blocked. It is possible that the proportioning valve has been disassembled by others and was re-assembled incorrectly. The proportioning valve can also appear to be perfect internally and yet not perform as intended, DAHIK.

 

The action of the pedal is fine, it requires a lot of force to get braking.

[mralex714]

Stiff probably isn't because they need to be bled.

 

Check the rear caliper. Look for the backing plates on the pads to have worn a slot on the front side of the caliper. If they're hanging up there it'll greatly reduce rear braking force.

 

I did find a raised area on the caliper when I changed the pads. I filed it down it seems to move freely.

[mralex714]

My brake pedal has been stiff since I bought the bike ,along with poor braking. When I apply the brake pedal there is very little braking until I press very hard and it feels like all the braking is from the front brake.. I have bled the brakes several times, it feels better but not as good as my 89. Any thoughts?

The brakes seemed to be better some day than others and really bad by the end o a ride. I finally rebuilt the rear master cylinder and so far that seems to have done the trick

[Ben Rollins]

Rebuilt my rear master last Sunday and so far so good as well. I was having to bleed every 2-3 days before. Wasn't as hard as I thought, although I did pull brake line out with master rather than taking it off master.