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View Full Version : Front Brakes, From hell's heart I stab at thee...



RockyMtnRoadRash
03-28-2005, 01:10 PM
*Sigh* I'm so over this old bike.

Saturday, in a fit of gratuitous overindulgence, I went skiing for the morning and riding in the afternoon. It started as a gentle rattle of my front fender.

It got worse and turned back into the the crappy pulsing brakes I thought Mike has exorcised by cleaning out the system.

When I got home I got down to get a closer look at the system. The area around where the hose attaches looked inexplicably wetter/shinier than the rest of the caliper, though there was no liquid to speak of, and the grime smelled like the normal rubber/earth/metallic tinge of roadgrime.

So, what are my possible culprits here? The gradual re-surfacing of the pulsing seems to point toward something in the lines, since every other part should be all or nothing, whereas the lines have a variable amount of fluid moving through them...

Where/what should I be inspecting in particular?

MarcS
03-28-2005, 01:51 PM
Where should you be inspecting? Your local dealership.
What should you be inspecting? Well, you'll figure it out.

:) :) :)

MikeInSLC
03-28-2005, 02:57 PM
could be that your hoses, fittings and banjo bolts, being older than the Earth, are letting air and crud into the system...remember when we bled your brakes and the fluid looked like coffee? that ain't right.

MarcS is right.

KZ-Rob
03-28-2005, 08:43 PM
warped rotors. Hydrulics dont pulse on their own. Air in the system would produce a spongey feel. A leak and the lever would "sink".

MikeInSLC
03-28-2005, 08:52 PM
That was my thought too at first, but after cleaning out the calipers and rotors and bleeding them, the puslation went away....only to return....

KZ-Rob
03-29-2005, 06:30 AM
did you take the caliper and or rotor off the bike? does it have single or dual disc?

MikeInSLC
03-29-2005, 07:12 AM
didn't take the rotor off....but did pull off the caliper to viausally inspect and clean....didn't take them apart. wiped down the rotors with brake cleaner. dual disc, both single pot calipers.

Bandalero
03-29-2005, 09:19 AM
:lolup: :lol2: :lolup:

Nothing to add except I love the title of this thread.

dcom
03-29-2005, 12:32 PM
Rob's right, hydralic brakes don't pulsate unless you're dealing with a warped or off-center rotor. Pulling the calipers then putting them back on probably reset their position on the rotor but if something's not right with the rotor, the vibration may come back, which it did. I'd look at that as the culprit. Check the rotor mounting and if you can, replace the rotor and check the pads to make sure they're wearing evenly.

The pulsing could be causing the pistons to force more back pressure on the fluid and if that may have caused a small amount of to leak out the fitting at the calipers enough to coat the area around the fitting but not enough to drip.

RockyMtnRoadRash
03-29-2005, 08:15 PM
On that note, I've happened across some rotors from an '80 on ebay that I can get on the cheap. Previous bike parts I've bid on have been sold to me for minimum bid, so I'm quite hopeful. There are a few upsides to having a really old bike.

Now I just have to hold out until July, then it's happy birthday to me with a shiny Volusia.

2 bucks for a spraycan of black primer, 2 bucks for some sandpaper, and my Ratitude will become official.

subvetSSN606
03-29-2005, 08:38 PM
I gotta agree... pulsing has to be the rotor warped or not aligned.
I've never run into it, but I throw this out for thought... or maybe someone has run into it, is it possible that a problem with the caliper combined with a problem with the rotor mount could pull the rotor out of alignment under the right conditions? I dunno... but might explain the problem disappearing and coming back.

Tom

KZ-Rob
03-30-2005, 07:02 AM
I gotta agree... pulsing has to be the rotor warped or not aligned.
I've never run into it, but I throw this out for thought... or maybe someone has run into it, is it possible that a problem with the caliper combined with a problem with the rotor mount could pull the rotor out of alignment under the right conditions? I dunno... but might explain the problem disappearing and coming back.

Tom
Its possible with a sliding caliper that doesn't slide, but not likely. Usually one pad will wear alot more than the other. Shudderbug had the answer.

RockyMtnRoadRash
04-04-2005, 10:34 AM
New rotors are on their way, courtesy of a parted out GS750 from 1980 on Ebay. Keeping my fingers crossed this set is better.

More bullitens as events warrent.