1100G brake question I can't answer???

[jimfj]

82 1100G with stainless lines.

I have completely gone through everything in the front brake system.
M/C rebuilt
New lines
Bled at every connection
Calipers removed and cleaned
Correct brake fluid
No leaks ar bubbles from anywhere.

The problem;
My brake lever has about a half inch of play before the pads actually start to come in contact with the rotors. I have even replaced the rubber piece that goes on the end of the "slide" for the calipers.

I have read in previous posts that removing the calipers and squeezing the lever till the pads just barely fit over the rotors then putting it all back together will solve the problem,,,,which it does.....for a time. After a while the problem just reoccurs. Its frustrating to say the least.

I bought a 650GL for a fixer upper and the brake on that one just feels a thousand times better, and its had been neglected for alot of years.

The actual stopping power is okay, the lever travel just gets worse over time.

This problem has been persisitant since I purchased the bike.

Any ideas on how to fix and what is actually loosening up?

 

[49er]

82 1100G with stainless lines.

I have completely gone through everything in the front brake system.
M/C rebuilt
New lines
Bled at every connection
Calipers removed and cleaned
Correct brake fluid
No leaks ar bubbles from anywhere.

The problem;
My brake lever has about a half inch of play before the pads actually start to come in contact with the rotors. I have even replaced the rubber piece that goes on the end of the "slide" for the calipers.

I have read in previous posts that removing the calipers and squeezing the lever till the pads just barely fit over the rotors then putting it all back together will solve the problem,,,,which it does.....for a time. After a while the problem just reoccurs. Its frustrating to say the least.

I bought a 650GL for a fixer upper and the brake on that one just feels a thousand times better, and its had been neglected for alot of years.

The actual stopping power is okay, the lever travel just gets worse over time.

This problem has been persisitant since I purchased the bike.

Any ideas on how to fix and what is actually loosening up?

Sounds like you still have some air in your brake system. Time for another bleeding session.

 

[jimfj]

No, Its not air. I don't mean to ask advice and not take it but

removing the calipers and squeezing the lever till the pads just barely fit over the rotors then putting it all back together will solve the problem,,,,which it does.....for a time. After a while the problem just reoccurs. Its frustrating to say the least.

I have dealt with plenty of systems with air still in them and they feel spongy. A system filled with air will allow the lever to be pulled almost to the handle bar as the air compresses. This is not the case at all. Once the pads come in contact with the rotors, I can lock them with two fingers if needed.

 

[DanTheMan]

Are your rotors worn down excessively? Have you measured them? Another point to consider would be the brake lever itself, if it is worn or damaged where it contacts the piston pushrod.

 

[dueller]

I was thinking rotors as well, but more on the lines they are warped. So when you set it up the first time the pads are right there, but as you ride it and the warped rotor runs between the pads it pushes the pads back as the high spot of the rotor runs thru the gap between the pads pushing them back in a bit every time and creating more gap than normal. Maybe?

 

[Stahlgrau333]

Warped rotors is exactly what I was thinking, as well.

 

[jimfj]

I have not measured the rotors but certainly will and report back.

I do noit believe they are warped. No pulsing feel to them at all. I will check runout there as well.

I have have not checked the wear on the lever.

Thanks for the suggestions.

 

[Buffalo Bill]

Never been there but, R & R the master cylinder?

Never been there but, R & R the master cylinder?

Well, maybe replace what's left: master cylinder, then brake calipers.
Or, maybe those new stainless lines are bum?
How did it brake before you replaced anything would be the strongest clue.

My 1100G has some room until the brake bites, all original parts, 36000 miles. It does bite, but it's a three finger job, it's a 550 lb. bike you know.

A 650G is about 100 lb lighter, not a bike the 1100G could out-brake.

When I do replace the lines in my bike, it will be with OEM.

Bill

 

[jimfj]

There is no comparision between OEM lines and stainless. When I grabbed the lever, I could see the rubber lines getting fatter. With the stainless it feels like you pull till you hit a block of wood. then you just decide how much you want to squeeze that block.

I would highly reccomend the stainless lines over OEM.

 

[bwringer]

This might sound off the wall, but...

I've had similar trouble when using shonky low-rent aftermarket brake caliper parts. The ill-fitting seal pulls the piston back too far.

The seal's elasticity is supposed to pull the piston back just a hair.

Rebuilding with OEM parts solved it.


Could also be disc runout, but this is fairly easy to spot -- just raise the front wheel and spin...

 

[jimfj]

I measured the rotors and they are within spec.

No, or very very little warping that I can see. I dont have a real good stand for my micrometer or runout guage but it's not moving the needle much at all.

I am leaning towards the Bwringer explaination. I will try and get some original parts and go from there.

any other ideas?

Jim

 

[gtsg01]

You mentioned changing the rubber boot on the caliper axle.

Do the axles float without resistance?

If the caliper is not floating as it should, it could put pressure on the piston.

Kind of a stretch, but stranger things have happened.