No pressure on front brake.

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Pop H
Posts: 7
Joined: Sun Jan 09, 2011 10:42 pm
Location: Northampton

No pressure on front brake.

Post by Pop H »

Following a high speed slide off last summer (and now recovered from my injuries!) I'm just completing repairs to my '98 Firestorm to get it back on the road ready for the spring.
The bike went down hard on it's right hand side, snapping the front brake lever amongst other damage, and once I got the bike back in my garage, I noticed that there was a slight leak of brake fluid around the master cylinder. I have taken the cylinder apart, checked seals, replaced the master cylinder piston, cleaned all parts and despite using every technique I know to refill and bleed the system I don't appear to get any pressure at the lever. Any thoughts anyone?

Pop H
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lloydie
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Joined: Mon Jan 17, 2011 11:16 pm
Location: In the garage somewhere in Coventry

No pressure on front brake.

Post by lloydie »

Air air air in the pipes me thinks .
Disconnect the brake pipe from the master cylinder and put your finger over the hole .
to seal the hole and pump the brake lever and then slowly remove your finger .
if you feel the pressure release you know it ain't the master cylinder to blame .
Air in the pipes or a leek . Always use new copper washers on the joints .
but if you can't heat the old one up on the cooler untill they change colour and then cool them in cold water .
That should soften them up to get a good air tight seal .
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sirch345
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Re: No pressure on front brake.

Post by sirch345 »

You could try (if you've not already) either removing just the master cylinder, or handlebar complete, then with the master cylinder fully horizontal bleeding it again. They are not the easiest to get the air out of.

Chris.
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lloydie
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Joined: Mon Jan 17, 2011 11:16 pm
Location: In the garage somewhere in Coventry

No pressure on front brake.

Post by lloydie »

Image
Next time I service the brakes I will be fitting these on the master cylinder and calipers
tony.mon
Posts: 16290
Joined: Wed Jul 25, 2007 10:46 pm
Location: Norf Kent

Re: No pressure on front brake.

Post by tony.mon »

A while back I had a problem bleeding the clutch on a member's bike, same principle applies though.
We found that there was a slight air leak on the bleed nipple; this meant that pumping the lever just pulled enough air in at the lower end so that fluid would not pump down the tube.

So try that, but also fit a syringe with a length of airline tubing to the drain nipple and keep a vacuum going while trying to bled it.
Takes two people, but works.
It's not falling off, it's an upgrade opportunity.
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