Brakes
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Joined: Sep 2008
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Brakes
My son inlaw has a 2004 Road king, and has a brake problem. everyday riding the brakes work fine but when on a trip and going to high altitudes the brakes fade, he needs to pump them to get normal braking action. he has stopped and checked the fluid level its good. anyone know what might be going on?
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Joined: Sep 2010
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From: Phoenix '53, '88, '09 Big Twins
could be the seals in the master cylinder.
test:
on a slight slope
apply brakes lightly to hold the bike steady--- using a zip tie is good- as our hand will change it's grip.
and just sit there for a few minutes...does the bike want to roll or will it hold position.
if it moves, the fluid is seeping past the MC seals.
if any part of the system is 'wet' you have a leak.
old fluid will hold water which will react at elevation, change it
if water in the fluid freezes, it may lock up the brakes--- rare on a bike, 'cause who's riding in freezing weather. I've seen this on cars though...poorly maintained cars
mike
test:
on a slight slope
apply brakes lightly to hold the bike steady--- using a zip tie is good- as our hand will change it's grip.
and just sit there for a few minutes...does the bike want to roll or will it hold position.
if it moves, the fluid is seeping past the MC seals.
if any part of the system is 'wet' you have a leak.
old fluid will hold water which will react at elevation, change it
if water in the fluid freezes, it may lock up the brakes--- rare on a bike, 'cause who's riding in freezing weather. I've seen this on cars though...poorly maintained cars
mike
Last edited by mkguitar; Aug 18, 2014 at 09:27 PM.
Club Member
Joined: Jun 2007
Posts: 45,429
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From: Bedford UK
Start by flushing out the old brake fluid with new, something we should all do at least every other year. It sounds as if he has a little air in the system, which he has got used to at his normal altitude, but which is affecting braking at higher altitude, with lower atmospheric pressure.
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Road Master
Joined: Jan 2008
Posts: 959
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From: Oswego, IL
I agree that the fluid is most likely the problem.
There are other things to check on 10 yr old calipers. Lyndall does a great write up in their tech section about dirty pistons on the older calipers.
http://www.lyndallbrakes.com/service-tech/
There are other things to check on 10 yr old calipers. Lyndall does a great write up in their tech section about dirty pistons on the older calipers.
http://www.lyndallbrakes.com/service-tech/
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