Topic: Front brake lever slack (fixed!)

[JDrider]

I have a 1975 cb550k1
When pulling the front brake lever there at least an inch of movement in before
Engaging the brake. Is this normal?
If not, how to fix.
I already replaced the master cylinder.
Install new brake lines.
Checked the caliper and cleaned inside.
Bled the system many times.
Got more air out of the top.

Maybe this is the way brakes worked on these bikes.
I don’t know because since I got it last year the front brake didn’t work.

[willbird]

I have a 1975 cb550k1
When pulling the front brake lever there at least an inch of movement in before
Engaging the brake. Is this normal?
If not, how to fix.
I already replaced the master cylinder.
Install new brake lines.
Checked the caliper and cleaned inside.
Bled the system many times.
Got more air out of the top.

Maybe this is the way brakes worked on these bikes.
I don’t know because since I got it last year the front brake didn’t work.

Usually this is the cause of the opposite condition, brakes dragging. But when you cleaned inside the caliper I presume you had the piston out ?? Was the O ring groove totally cleaned of any crusty residue ?? The square section O ring by design  deforms under pressure in this system. When the pressure is released the O ring relaxing is what retracts the piston so it does not drag. There is a spec on the width of the O ring groove probably. I'd probably rebuild the caliper with new parts, from what you said I'm thinking you did not ?

Bill

[grcamna2]

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[JDrider]

When I re did the whole system, I ordered a new piston and ring but
Didn’t realize it wasn’t original brakes, it was an aftermarket.
Also the insides and piston and ring seemed new. I cleaned up and reused.
The replacement didn’t fit inside. Was a hair larger.

The the calipers are after market.

[Don R]

 It's not normal. Air in the lines maybe? If so, leaving rubber bands on the lever overnight has helped me. The air bubbles get smaller under pressure and float up to the bleed hole in the M/C.
 A smaller than stock master cyl. will require more travel to operate but should not travel that much.

[CycleRanger]

It's not normal. Air in the lines maybe? If so, leaving rubber bands on the lever overnight has helped me. The air bubbles get smaller under pressure and float up to the bleed hole in the M/C.
 A smaller than stock master cyl. will require more travel to operate but should not travel that much.

If you do this follow this technique.

[JDrider]

So, someone in this forum mentioned pumping the lever to get the piston
To move mostly out and then push all the way back in by hand.
I did this a couple times.
Also I greased around the brake pad, so it glides better.
Put everything back together and the brakes seem to be feeling normal now.
So I’m happy. Thanks everyone.