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'72 Roadster - front brake

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I have the front master brake upgrade Grimeca kit 13-1600 from Andover Norton fitted to my bike.

The lever nearly comes back to the bar and I've replaced the fluid and bleed the brakes twice - I don't think there is any air in the system.

The lever seems to do nothing until half its travel has been used, at which point it starts to bite and then is fully on as it touches the bar - not ideal!

I've also stripped the caliper and replaced the seals and pads - just the same.

Any ideas?

Regards - Paul.

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Paul,

Normal bleeding is not enough. The brake hose that comes with this kit has a very small internal diameter, and we have found it needs to be drained with vacuum draining equipment to get all the air out. It sounds as if you still got an air bubble somewhere.

I have the system on my "Three cylinder Commando" (the Dougg Hele balancer engine bike), and my son has it on his Commando, plus several (local) friends of mine have it on. The initial draining was found to be crucial, and the kit should have come with instructions that stress the fact normal bleeding by hand will not do.

Regards

Joe

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I have no knowledge of this particular kit, but I found out many years ago that in many brake systems the tiny bubbles can be helped to rise up overnight. After bleeding, that includes easing the lever forward as slowly as possible on the last few pumps, tighten everyting up and pull the lever back hard wrapping a FAT rubber band around it and the grip - a piece of inner tube makes a nice big rubber band. The theory is that the tiny bubbles can rise up the hoses and pass through the open master cylinder ports. In the morning you might find it much better.

Norm.

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Thanks for the tips - I'll try the band method first.

Joe - what's the best place to get a vacuum draining kit?

Regards - Paul.

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Paul,

You can either go to a garage and let them bleed it, or buy a system that works with your compressor (if you have one); very cheap these days from people like Gericke and other accessory places, about 20 to 30 Ponds if I remember correctly.

 



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